Article

Limitation of African Wild Dogs by Competition with Larger Carnivores

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Abstract

African wild dogs (Lycaon pictus) are endangered largely because their population-density is low under all conditions. Interspecific competition with larger carnivores may be a factor limiting wild dog density. The density of wild dogs on a 2600-km² area of the Selous Game Reserve (Tanzania) was 0.04 adults/km². Spotted hyaena (Crocuta crocuta) density for the same area was estimated by audio playbacks as 0.32 hyaenas/km². Lion (Panthera leo) density, determined from the ratio of hyaenas to lions, was 0.11 lions/km². Across six ecosystems including Selous, there were strong negative correlations between wild dog and hyaena densities (r = −0.92; p = 0.01) and between wild dog and lion densities (r = −0.91; p = 0.03). Hyaenas out-numbered wild dogs by ratios ranging from 8:1 to 122:1. Ratios of lions to wild dogs ranged from 3:1 to 21:1. The diets of hyaenas and wild dogs overlap extensively; those of wild dogs and lions show less overlap. Where hyaenas are common and visibility is good, interference competition from hyaenas at wild dog kills is common and reduces wild dogs’ feeding time. Where hyaena density is lower and visibility is poor, interference competition at wild dog kills is rare. Wild dogs are commonly killed by lions and occasionally by hyaenas. These data suggest that competition with spotted hyaenas may limit or exclude wild dogs when hyaena density is high. Competition with lions appears less intense, but direct predation by lions on wild dogs is important. Competition and predation by larger carnivores may be of broad importance to the conservation of wild dogs and other medium-sized carnivores.

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... The population density of dominant competitors such as lions (Panthera leo) is strongly correlated with prey density, and decreases in response to prey depletion [67,69]. Densities of subordinate competitors such as wild dogs (Lycaon pictus) and cheetah (Acinonyx jubatus) are not tightly correlated with prey density, but are negatively correlated with the density of their dominant competitors [11,30,36,47,48,63]. Recent research has shown that the reduction of dominant competitors (lions) does not necessarily release subordinate competitors (wild dogs), if the low density of dominant competitors is caused by prey depletion [28]. ...
... Recent research has shown that the reduction of dominant competitors (lions) does not necessarily release subordinate competitors (wild dogs), if the low density of dominant competitors is caused by prey depletion [28]. Much research has described the effects of dominant competitors on the distribution and abundance of subordinate carnivores in ecosystems with intact prey communities [11,43,57], but we know little about these effects when both prey and dominant competitors are reduced (a condition that is increasingly common). ...
... Large carnivores often compete by interference. Wild dogs are strongly affected by kleptoparasitism by spotted hyenas [11,21,22,29] and intraguild predation by lions [11,30,47]. According to Gause's law, selection should favor adaptations that reduce niche overlap between pairs of competing species (particularly in subordinate competitors), and for large carnivores these adaptations usually reduce overlap in the set of prey species that is hunted, temporal patterns of hunting activity, or space use. ...
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Background Prey depletion is a threat to the world’s large carnivores, and is likely to affect subordinate competitors within the large carnivore guild disproportionately. African lions limit African wild dog populations through interference competition and intraguild predation. When lion density is reduced as a result of prey depletion, wild dogs are not competitively released, and their population density remains low. Research examining distributions has demonstrated spatial avoidance of lions by wild dogs, but the effects of lions on patterns of movement have not been tested. Movement is one of the most energetically costly activities for many species and is particularly costly for cursorial hunters like wild dogs. Therefore, testing how top-down, bottom-up, and anthropogenic variables affect movement patterns can provide insight into mechanisms that limit wild dogs (and other subordinate competitors) in resource-depleted ecosystems. Methods We measured movement rates using the motion variance from dynamic Brownian Bridge Movement Models (dBBMMs) fit to data from GPS-collared wild dogs, then used a generalized linear model to test for effects on movement of predation risk from lions, predictors of prey density, and anthropogenic and seasonal variables. Results Wild dogs proactively reduced movement in areas with high lion density, but reactively increased movement when lions were immediately nearby. Predictors of prey density had consistently weaker effects on movement than lions did, but movements were reduced in the wet season and when dependent offspring were present. Conclusion Wild dogs alter their patterns of movement in response to lions in ways that are likely to have important energetic consequences. Our results support the recent suggestion that competitive limitation of wild dogs by lions remains strong in ecosystems where lion and wild dog densities are both low as a result of anthropogenic prey depletion. Our results reinforce an emerging pattern that movements often show contrasting responses to long-term and short-term variation in predation risk.
... The densities of dominant competitors such as lions (Panthera leo) are strongly correlated to prey density (Van Orsdol et al., 1985), and thus decrease in response to prey depletion (Vinks et al., 2021). The survival rates and population densities of subordinate competitors such as the African wild dog (Lycaon pictus) and cheetah (Acinonyx jubatus) are less tightly correlated with prey density, but are negatively correlated with the density of dominant competitors (Creel and Creel, 1996;Kelly et al., 1998;Mills and Biggs, 1993;Mills and Gorman, 1997;Swanson et al., 2014). The expected effect on subordinate competitor populations from a decline of both prey and competitors is not entirely clear, and has immediate conservation implications . ...
... African wild dogs provide a good opportunity to study the effects of resource depletion on subordinate competitors that are limited by interference and exploitative competition. Wild dogs are limited by interactions with lions and spotted hyenas (Crocuta crocuta) in many ecosystems through the effects of kleptoparasitism and intraguild predation Creel and Creel, 1996;Fanshawe and Fitzgibbon, 1993;Gorman et al., 1998;Mills and Gorman, 1997;Speakman et al., 2015;Swanson et al., 2014). As a result, wild dogs consistently select areas with low lion density (Dröge et al., 2017;Estes and Goddard, 1967;Mills and Gorman, 1997;Vanak et al., 2013), and populations respond positively to low densities of lions and hyenas (Creel and Creel, 2002;Pole, 2000). ...
... As a result, wild dogs consistently select areas with low lion density (Dröge et al., 2017;Estes and Goddard, 1967;Mills and Gorman, 1997;Vanak et al., 2013), and populations respond positively to low densities of lions and hyenas (Creel and Creel, 2002;Pole, 2000). Wild dogs have historically occurred at low density (Selous, 1908) and they never attain population densities comparable to their dominant competitors (Creel and Creel, 1996). They have long been considered endangered by the IUCN, with fewer than 6000 individuals remaining (Fanshawe et al., 1991;Woodroffe and Sillero-Zubiri, 2020), though there is considerable uncertainty about this number and how it may be changing. ...
Article
Conservation of competitively subordinate carnivores presents a difficult challenge because they are limited by dominant competitors. Prey depletion is one of the leading causes of large carnivore decline worldwide, but little is known about the net effect of prey depletion on subordinate carnivores when their dominant competitors are also reduced. African wild dogs are often limited by high densities of dominant competitors, particularly lions. We measured African wild dog density and survival, using mark-recapture models fit to 8 years of data from 425 known individuals in the Greater Kafue Ecosystem, Zambia. The GKE is affected by prey depletion, particularly of large herbivores, and thus the density of lions is significantly lower than ecologically comparable ecosystems. Counter to expectations from mesopredator release theory, wild dog density in GKE was far lower than comparable ecosystems with higher lion and prey density, though annual survival rates were comparable to large and stable populations. Average pack size was small and home range size was among the largest recorded. Our results show that low lion density did not competitively release the GKE wild dog population and we infer that the low density of wild dogs was a product of low prey density. Our results suggest that there is an optimal ratio of prey and competitors at which wild dogs achieve their highest densities. This finding has immediate implications for the conservation of the endangered African wild dog, and broad implications for the conservation of subordinate species affected by resource depletion and intraguild competition.
... Interspecific competition can be a dominant factor influencing the dynamics of carnivore populations (Creel et al., 2002). Creel and Creel (1996) showed that African wild dog populations are negatively correlated with the density of lions and spotted hyaenas across study sites in Africa. As a result wild dogs tend to avoid areas of high lion and spotted hyaenas density. ...
... As a result wild dogs tend to avoid areas of high lion and spotted hyaenas density. However such areas are mostly characterised by high populations of ungulates (Creel and Creel, 1996). As a result populations of lions and spotted hyaenas all tend to attain high densities in such areas while African wild dogs attain very low densities in such ecosystems. ...
... This therefore show that the presence of the bigger predators partially exclude African wild dogs from their preferred habitats (Mills and Gorman, 1997 (Mills and Gorman, 1997). It is important to note that in areas of high prey populations it is not live prey that is competed for but the kill itself (Creel and Creel, 1996) and the level will actually increase with increases in prey species and this makes African wild dogs highly susceptible to the edge effect (Lindsey et al., 2004). ...
Thesis
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African wild dogs have declined in numbers over the past years. Their persistence is largely dependent on effective conservation and management strategies. In Zimbabwe, although the population is threatened, packs in Mana Pools National Park (MNP) are characterized by larger packs compared to those in Hwange National Park (HNP). The study aims at comparing the pack sizes, pup production, pup survival, recruitment, pack longevity, and sex ratios between the two populations. The life histories of 8 packs in HNP and 7 packs in MNP that existed in the period 2007 – 2012 were followed using, photographs, direct observation, and survey forms. From which the data on pack sizes, pup production and pup survival, recruitment, pack longevity, and sex ratios were determined. Results show that there were significant differences in pack sizes, with MNP packs being bigger relative to those in HNP (two way ANOVA, F (1,5) = 32.92, p < 0.001). In all reproduction parameters (pup production, pup survival, and recruitment) HNP had significantly lower values compared to MNP (p < 0.001). There were no significant differences in pack longevity between the two populations (Mann-Whitney U = 12.5, p = 0.075). Sex ratios did not significantly differ between the two populations (Chi-square χ2 = 0.85; 1 df; p = 0.36). This shows that HNP packs are very much at risk of local extirpation due to low pack sizes, which has implications in their ability to successfully reproduce. Conservation efforts should thus be intensified in protecting the existing packs in HNP from further loss of individuals due to snaring and road kills, which have been shown to be the major causes of mortality. There is also need for further research on why packs in HNP are failing to reproduce, the causes of pup mortality, and the likely impacts of other keystone species such as elephants on African wild dogs.
... An ecological community is an assemblage of interacting species that are interdependent. Of these interactions, competition has been shown to alter population densities (Hairston 1951), foraging efficiency, growth, age structure (Cameron et al. 2007), habitat use (Creel and Creel 1996), and activity patterns (Ziv et al. 1993;Jones et al. 2001), and hence holds a central place in ecological and evolutionary theory (MacArthur and Levins 1964Levins , 1967Abrams 1980;Gurevitch et al. 1992). Ecological competition is perceived as an impediment to species coexistence and community diversity and hence has been the catalyst for studies examining the conditions under which coexistence between interacting species is possible (Chesson and Huntly 1997;Gordon 2000). ...
... Understanding interspecific interactions in synoptic species has implications for species conservation (Creel and Creel 1996;Linnell and Strand 2000). For example, the interaction of cheetahs with other sympatric carnivores has been shown to have a profound impact in the population abundance of cheetahs (Creel and Creel 1996). ...
... Understanding interspecific interactions in synoptic species has implications for species conservation (Creel and Creel 1996;Linnell and Strand 2000). For example, the interaction of cheetahs with other sympatric carnivores has been shown to have a profound impact in the population abundance of cheetahs (Creel and Creel 1996). Lions, hyaenas and African wild dogs were found to compete with cheetahs for prey, which caused cheetahs to occupy habitats with low densities of lions, hyenas and wild dogs (Creel and Creel 1996). ...
Article
Full-text available
Understanding the conditions under which interacting species can persist is a major goal in ecology. Dietary partitioning is one of the major strategies that enables ecologically similar species to coexist in communities. In this study, we examined the dietary patterns of a selected group of amphibians in an amphibian community in northern Sri Lanka to understand differential resource use by coexisting species. The stomach flushing method was used to examine the diet of amphibians to study the niche breadth and pairwise species dietary niche overlap. Seventeen different prey categories were identified from the diet of six species of amphibians in the community. The most frequently used prey category by all amphibians was hymenoptera. Among the amphibians, some consumed several different prey categories (8–9 prey categories), while some were more specialised (e.g. Uperodon rohani fed only on ants), consuming only one or two different prey categories. The average niche overlap among the species in the community was 0.392 indicating low trophic niche overlap. This study indicates a low level of dietary niche overlap between the selected amphibian species and hence, a high degree of dietary niche partitioning. The findings also provide valuable insights into the dietary ecology of these amphibians, which will be invaluable for the formulation of conservation strategies.
... Their population showed abundance increased while their prey periwinkle snails, which are grazing prey, saw a decline in their population. Wild dog (Lycaon pictus) competition with large predators such as Spotted hyena (Crocuta crocuta) and Lion (Panthera leo) may result into hyenas outnumbering and hence eliminating wild dogs into the Selous Game Reserve, Tanzania (Creel and Creel, 1996). Again, lion killing wild dog statistics is minimal but cannot be ignored for the healthier ecosystem (Creel and Creel, 1996). ...
... Wild dog (Lycaon pictus) competition with large predators such as Spotted hyena (Crocuta crocuta) and Lion (Panthera leo) may result into hyenas outnumbering and hence eliminating wild dogs into the Selous Game Reserve, Tanzania (Creel and Creel, 1996). Again, lion killing wild dog statistics is minimal but cannot be ignored for the healthier ecosystem (Creel and Creel, 1996). The above studies show that large predators play a crucial role in being on top of the food chain. ...
Article
Full-text available
Wildlife, as well as human beings, are prone to be affected by fear. Large predators and mesopredators usually produce this fear in animals. This effect is recognised in the form of various behavioural changes and adaptations, which, in turn, affects the whole ecosystem. However, we often overlook the role of large predators and mesopredators in the sustenance of our ecosystem by such non-lethal effects, because fear is often seen as a psychological effect rather than something that can be found through explicit scientific means. Indeed, the fear that predators trigger inside their prey may play a significant role in the maintenance of the natural environment. This paper aims to analyse this hypothesis by reviewing the function of the ecology of fear based on the interaction among predators, prey, and mesopredators. We consider the factors involved in the effective functionality of the ecology of fear, including habitat landscape, season, weather, and predation risk. We also assess the extent of influence of large predators on behaviour and distribution of prey and mesopredators in terms of predation cues and prey grouping as responses to predation risk. Finally, we discuss the implications of fear ecology for wildlife conservation and management and new challenges.
... Dynamics among mesocarnivores and their resulting effects on community composition and trophic cascades have been well studied in North America, Europe, and Australia (e.g., Johnson & VanDerWal, 2009;Levi & Wilmers, 2012;Pasanen-Mortensen, Pyykönen, & Elmhagen, 2013;Sivy, Pozzanghera, Grace, & Prugh, 2017) and for larger carnivores in Africa (e.g., Creel & Creel, 1996;Durant, 1998;Rich et al., 2017). For example, in the absence of wolves (Canis lupus) in much of the United States, coyotes (Canis latrans) have become dominant carnivores, suppressing or changing the activity patterns of smaller carnivores such as foxes (Urocyon cinereoargenteus, Vulpes velox, and Vulpes vulpes) and increasing bird diversity (Fedriani, Fuller, Sauvajot, & York, 2000;Harrison, Bissonette, & Sherburne, 1989;Levi & Wilmers, 2012;Thompson & Gese, 2007). ...
... Africa (e.g., Creel & Creel, 1996;Johnson & VanDerWal, 2009;Levi & Wilmers, 2012;Pasanen-Mortensen et al., 2013;Sivy et al., 2017). ...
Article
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Mesocarnivores constitute a diverse and often abundant group of species, which are increasingly occupying hweigher trophic levels within multi‐use landscapes. Yet, we know relatively little about their interactions with each other, especially in human‐altered areas. Using camera trap data collected in a forestry concession in the Greater Gorongosa ecosystem of central Mozambique, we examined the spatiotemporal relationships and potential for intraguild competition among three understudied African carnivores: African civets (Civettictis civetta), bushy‐tailed mongooses (Bdeogale crassicauda), and large‐spotted genets (Genetta maculata). After accounting for habitat preferences and tolerance to anthropogenic factors, we found that African civets and bushy‐tailed mongooses avoid each other spatially and temporally. Additionally, civets and mongooses were also both more likely to use sites farther away from human settlements, possibly decreasing the total available habitat for each species if competition is driving this spatial partitioning. In contrast, we did not find evidence for spatial or temporal partitioning between large‐spotted genets and African civets, but bushy‐tailed mongooses altered their activity patterns where they co‐occurred with genets. Our study contributes to scant ecological knowledge of these mesocarnivores and adds to our understanding of community dynamics in human‐altered ecosystems.
... Having such information will allow for informed conservation strategies. Over the past century or more both species have been heavily impacted by anthropogenic pressures namely habitat loss and fragmentation; poaching (through the uses of snaring wires); illegal wildlife (lion bones as ingredients in 'tiger bone wine') uses (Nowell and Ling, 2007) and human-wildlife conflicts (Creel and Creel, 1996;East and Hofer, 1996;Fanshawe et al, 1997;Mills and Gorman, 1997;Woodroffe and Ginsberg, 1998;Balme et al, 2010;Lindsey et al, 2011;Davies-Mostert et al, 2015;Miller et al, 2015). Because of these ongoing threats in many regions lions are currently defined as "vulnerable" according to the International Union for Conservation of Nature's (IUCN) Red List (IUCN, 2014). ...
... Currently, the species are categorized as "endangered" in the wild (IUCN, 2006;McNutt et al, 2004) on the basis of low population densities within South African Parks and further declines . African wild dogs' are highly social, cooperative, and successful hunters that live mainly in packs ranging from 3 to more than 20 individuals (Burrows, 1993;Creel and Creel, 1996;Creel, 1997;Rasmussen et al, 2008). Pack sizes generally depend on the environment the wild dogs' are exposed to and how well the dogs have access to valuable resources. ...
Thesis
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Substantial amounts of conservation research towards African wild dogs (Lycaon pictus) and African lions (Panthera leo) currently exist globally, and much is known about the ecology, behaviour and conservation between both predators. Moreover, with the planet consistently changing at rates that humanity can barely manage, the affects and survival pressures which are surrounding the lives among wild dogs and lions are still unknown. Both species are under many threats caused by biotic and abiotic factors and it is of utmost importance to continue in understanding these animals to best implement the best conservation action practices. This study addresses the knowledge gap in the preferential prey selection types between both predators at the Somkhanda Private Game Reserve, to help determine whether there are any overall trends, dietary overlaps and if the reserve itself has enough prey base to support the wild dogs and lions. While both of these predators’ prey preferences have been widely studied in other areas throughout Africa, a study of this kind has not been carried out before at this private game reserve. Using historical prey mortality data, game census data/annual population estimates and vegetation/habitat references of the reserve, this study investigated whether the abundances between both predators have an influence towards one another’s prey selection at the Somkhanda Private Game Reserve.The introduction of lions at Somkhanda Private Game Reserve clearly had an influence towards the wild dog’s behaviour and feeding ecology, as the results before lions arrived at the reserve and after they arrived illustrate huge differences in wild dog pack distributions. Both predators share similar habitat types which contain similar prey species, and as an affect of this the wild dogs have been marginalised through interspecific resource pressures. African wild dogs clearly had the advantage before the lions arrived at the reserve, as optimal foraging opportunities led to more varieties in prey species consumed. The presence of lions indicate that wild dogs avoided the habitats which contained the lions, even if their favoured prey were available and resulted towards edge effects. The analyses demonstrate the pack of wild dogs were pushed towards the fence lines of the reserves due to influences of lions within the habitat areas, limiting the amount of prey selection which would’ve occurred before the lions were introduced into the reserve. Although, Somkhanda Private Game Reserve has enough prey base to support both carnivores, competition for preferred prey and dietary overlaps could inevitably affect the overall survival rates of the wild dogs.
... The same study found that African wild dogs exhibited extreme avoidance behaviours by existing in areas with the lowest resources in order to avoid lions, leopards and cheetah (Vanak et al., 2013). Multiple studies have shown that hyena and lion populations shows a strong negative correlation with both African wild dog and cheetah, suggesting that interspecific competition and predation may be an issue (Creel and Creel, 1996;Durant, 1998;Wasiolka and Blaum, 2011;Vanak et al., 2013). This competition is likely to cause changes in behaviour such as active avoidance and variation in habitat use (Caro and Stoner, 2003). ...
... As noted in Chapter 1, African Wild Dogs exhibit extreme avoidance behaviour in the presence of lions, leopards and hyena (Creel and Creel, 1996;Vanak et al., 2013). It is possible that this has caused the extirpation of African Wild Dogs in the area. ...
Thesis
Full-text available
As part of my Master of research (MRes) degree, I conducted a camera trapping survey in a remote reserve in Northern Malawi. This was done in collaboration with Conservation Research Africa and Carnivore Research Malawi with data contributed by Lilongwe Wildlife Trust and Biosphere Expeditions. The aim of this study was to assess the species composition and distribution in the reserve and provide management recommendations to aid the future conservation of these species. During 8 weeks of fieldwork in Malawi, I analysed footage from 70 camera stations which was collected over 543 total trapping days. This was the first large-scale camera trapping study to be conducted in the reserve. I analysed this data using QGIS mapping software and R statistical software. I identified a total of 37 species including 17 carnivores. These were subdivided into 3 large carnivore species and 14 mesocarnivores. Four of these had never been seen in the reserve before. One species, the Angolan Genet, was found to be over 300km outside of its previously known geographic range, and a paper was subsequently published about this discovery. It was also shown that there is a higher density of carnivores near the boundary of the reserve, especially in the southeast around Lake Kazuni. This is an area of high human use, which leads to concerns about humanwildlife conflict. The results of this study suggests that this area should be considered a high priority when addressing conflict.
... We assessed collinearity between independent explanatory variables prior to analysis using variance inflation factors (VIF) and Spearman rank correlation tests. All correlations had Spearman's rho < 0.5 and all variables had VIF values < 2. Lions occur in areas of high overall herbivore density and, in the KNP, the area of highest lion density has a high prey biomass of 2,749 kg/km 2 (comprising the species; African buffalo, giraffe Giraffa camelopardalis, impala, Plains zebra Equus quagga, warthog Phacochoerus africanus, blue wildebeest Connochaetes taurinus, Greater kudu, and waterbuck Kobus ellipsiprymnus; Creel and Creel 1996;Ferreira and Funston 2010). Thus, although lions can occur in the high herbivore biomass regions of the KNP, lion density and impala density were not correlated in our study (r < −0.01, P = 0.36). ...
... Apex lions anchor themselves in areas of high The effect of (a) lion density (lions/km 2 ) and impala density (impalas/km 2 ) on denning season re-visitation, (b) impala density (impalas/km 2 ) and distance from the den site (km) on denning season visit duration, and the effect of impala density (impalas/km 2 ) and lion density (lions/km 2 ) on (c) non-denning re-visitation and (d) non-denning visit duration by 19 African wild dog packs in the Kruger National Park. herbivore density (Creel and Creel 1996;Ferreira and Funston 2010) and, although not always the case (Comley et al. 2020), avoiding lions may mean avoiding resource-rich areas (Mills and Gorman 1997). However, because impala density and lion density were not correlated in our study (the KNP is very heterogenous; Biggs et al. 2003), and likely because lions avoid impalas (Hayward and Kerley 2005), it was therefore possible for wild dogs to utilize impala-rich patches while still avoiding areas of high lion density. ...
Article
The risk of predation can alter the way animals perceive costs and benefits in their environment, on which foraging decisions are made. To maximize fitness, animals with offspring show the most pronounced alteration in behavior because mothers experience increased nutritional requirements and increased vulnerability to predation. Therefore, the tolerance of risk is shaped, in part, by reproductive state. Like prey species, mesopredators balance a trade-off between food and predation to maximize fitness. However, few studies have acknowledged its importance. We investigated how mesopredators may alter their space use between periods when young are and are not vulnerable. Investigating the fine-scale space use of 19 packs of African wild dogs Lycaon pictus in the Kruger National Park, we found lower risk tolerance of denning packs; they re-visited area less frequently as lion and impala density increased and thus reduced the likelihood of risky encounters by avoiding areas where both risk and reward were high. By contrast, non-denning packs re-visited area less frequently as lion density increased and impala density decreased and thus avoided areas where reward was low, especially if risk was high. These results suggest that wild dogs shift their patterns of space use when the pack is most vulnerable. Ultimately, we found evidence of decreased risk tolerance by denning packs, likely because of increased vulnerability of lactating mothers and immobile pups. More broadly, our findings suggest that risk tolerance is dependent on reproductive state for mesopredators and should be considered as a possible mechanism for other mesopredators as well.
... Their population showed abundance increased while their prey periwinkle snails, which are grazing prey, saw a decline in their population. Wild dog (Lycaon pictus) competition with large predators such as Spotted hyena (Crocuta crocuta) and Lion (Panthera leo) may result into hyenas outnumbering and hence eliminating wild dogs into the Selous Game Reserve, Tanzania ( Creel and Creel, 1996). Again, lion killing wild dog statistics is minimal but cannot be ignored for the healthier ecosystem ( Creel and Creel, 1996). ...
... Wild dog (Lycaon pictus) competition with large predators such as Spotted hyena (Crocuta crocuta) and Lion (Panthera leo) may result into hyenas outnumbering and hence eliminating wild dogs into the Selous Game Reserve, Tanzania ( Creel and Creel, 1996). Again, lion killing wild dog statistics is minimal but cannot be ignored for the healthier ecosystem ( Creel and Creel, 1996). The above studies show that large predators play a crucial role in being on top of the food chain. ...
Article
Wildlife, as well as human beings, are prone to be affected by fear. Large predators and mesopredators usually produce this fear in animals. This effect is recognised in the form of various behavioural changes and adaptations, which, in turn, affects the whole ecosystem. However, we often overlook the role of large predators and mesopredators in the sustenance of our ecosystem by such non-lethal effects, because fear is often seen as a psychological effect rather than something that can be found through explicit scientific means. Indeed, the fear that predators trigger inside their prey may play a significant role in the maintenance of the natural environment. This paper aims to analyse this hypothesis by reviewing the function of the ecology of fear based on the interaction among predators, prey, and mesopredators. We consider the factors involved in the effective functionality of the ecology of fear, including habitat landscape, season, weather, and predation risk. We also assess the extent of influence of large predators on behaviour and distribution of prey and mesopredators in terms of predation cues and prey grouping as responses to predation risk. Finally, we discuss the implications of fear ecology for wildlife conservation and management and new challenges.
... Spotted hyaena also typically dominate over leopard [24], and there is evidence of temporal partitioning between the two species [25]. Both lion and spotted hyaena are also known to kill, steal food from, and display aggression towards cheetah (Acinonyx jubatus) [26,27] and African wild dog (Lycaon pictus) [28,29]. Very little is known about intra-guild interactions of striped hyaena (Hyaena hyaena), but it is likely that they share a similar competitive status to brown hyaena (Parahyaena brunnea), below spotted hyaena and lion [30]. ...
Article
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Africa is home to some of the world’s most functionally diverse guilds of large carnivores. However, they are increasingly under threat from anthropogenic pressures that may exacerbate already intense intra-guild competition. Understanding the coexistence mechanisms employed by these species in human-impacted landscapes could help shed light on some of the more subtle ways in which humans may impact wildlife populations, and inform multi-species conservation planning. We used camera trap data from Tanzania’s Ruaha-Rungwa landscape to explore temporal and spatiotemporal associations between members of an intact East African large carnivore guild, and determine how these varied across gradients of anthropogenic impact and protection. All large carnivores except African wild dog ( Lycaon pictus ) exhibited predominantly nocturnal road-travel behaviour. Leopard ( Panthera pardus ) appeared to employ minor temporal avoidance of lion ( Panthera leo ) in all sites except those where human impacts were highest, suggesting that leopard may have been freed up from avoidance of lion in areas where the dominant competitor was less abundant, or that the need for leopard to avoid humans outweighed the need to avoid sympatric competitors. Lion appeared to modify their activity patterns to avoid humans in the most impacted areas. We also found evidence of avoidance and attraction among large carnivores: lion and spotted hyaena ( Crocuta crocuta ) followed leopard; leopard avoided lion; spotted hyaena followed lion; and lion avoided spotted hyaena. Our findings suggest that large carnivores in Ruaha-Rungwa employ fine-scale partitioning mechanisms to facilitate coexistence with both sympatric species and humans, and that growing human pressures may interfere with these behaviours.
... Dietary interactions between predator species are an important aspect of predator ecology and can include resource partitioning, interference or exploitative competition, and intraguild predation (Creel and Creel 1996;Mills and Gorman 1997;Fedriani et al. 2000;Glen et al. 2011). For native predators, dietary flexibility and interactions have formed through coevolution with sympatric predators under the same environmental conditions, facilitating coexistence (Glen and Dickman 2005). ...
Article
Predator diet can be influenced by competition and intraguild predation, leading to resource partitioning and/or avoidance. For sympatric, endemic predators, these processes form as predator species coevolve, facilitating coexistence. However, when novel predator interactions occur, significant dietary overlap could create acute levels of competition leading to intraguild predation and population extinction, or accelerated changes in diet and/or spatial and temporal avoidance. We measured diet, intraguild predation, and spatial and temporal overlap in two predator species in a novel predator interaction: the western quoll (Dasyurus geoffroii), a small, native carnivore reintroduced to semi-arid Australia, and the domestic cat (Felis catus), a larger introduced carnivore already resident at the release site. Both species exhibited high dietary overlap and fed on mammals, reptiles, birds, and invertebrates. Cats included quolls in their diet. Quoll diet was broader (including carrion, bats, and plant material) and flexible, changing significantly with age, sex, and season. Introduced rabbit was the most common prey item recorded for both species (frequency of occurrence = 40–50%). However, quolls consumed rabbits in relation to their availability while rabbit consumption in cats was unrelated to availability suggesting a stronger dependence on rabbit prey. Quoll diet did not change over time since release and they did not spatially or temporally avoid cats. However, cats were significantly spatially associated with rabbits while quolls were not, suggesting higher predation efficacy in quolls possibly due to their smaller body size enabling them to catch rabbits inside warrens. Despite high dietary overlap and intraguild predation, the quoll’s broad and flexible diet and high predation efficacy appeared to assist in facilitating coexistence and reducing competition in this novel predator interaction. This dietary flexibility may be harnessed to improve conservation outcomes: reducing introduced rabbits in our study area could naturally reduce feral cat populations while having less impact on native quolls.
... Interspecific interactions among large carnivores that vary from trophic facilitation to competition can really affect the ecology of subordinate predators which ranges from change in patterns of space, time and food use to decline in population (Creel andCreel 1996, Harihar et al. 2011). We found eight studies which carryout to understand the interspecific interactions among leopards with tiger and dhole (Seidensticker 1976, Odden et al. 2010, Harihar et al. 2011, Ramesh et al. 2012b, Bhattarai and Kindlmann 2012, Lovari et al. 2014, Carter et al. 2015, Karanth et al. 2017. ...
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Leopards are most widespread member of family Felidae and have nine subspecies across the world. We reviewed the literature on the Indian leopards to summarize the extent of research efforts and current ecological understanding. We reviewed 105 studies published from 1960 to 2018 in 55 journals, and summarized the knowledge on evolution and taxonomy, status and distribution, abundance and density, feeding habits, spatial ecology, activity pattern, human-leopard conflict, interspecific interactions and habitat. Most of the studies were from protected areas as compared to non-protected areas while only three studies were conducted in ex-situ conditions. Human-wildlife conflict along with feeding habits were the most studied aspects while spatial and temporal ecology and behavior were the least studied aspects. Already lost 70% of its historical range, Indian leopards presently have patchy distribution. High densities of leopards were visible in prey rich areas. Leopard's diet was dominated by wild ungulates in PA's while in human dominated landscape, dogs and livestock were dominant. Indian leopards have smaller home ranges as compared to the African relatives. Leopards show activity peaks during down and dusk time of the day. Cover was an important factor affecting the presence of leopards. Leopards coexist with other large predator by fine adjustment in use of space time and food. Human-leopard conflict was one of the most studied aspect. Studies shows site dependency of conflict. Most severe conflict was livestock depredation. Important factor affecting conflict were occupation of humans, husbandry practices, change in land use pattern and successful conservation in some areas. Present policies to manage conflict seem insufficient. Feeding and behavioral plasticity makes leopards successful survival of human dominated landscapes. Apart from conflict and dietary studies, there is a lack of studies on ecological aspects such as population size, spatial ecology, interspecific interactions, habitat and behavior. These studies are needed to improve our understanding of their ecology for effective conservation. There is also an urgent need to look into the policies regarding management of human-wildlife conflict.
... Leopards abundance was higher compared to other two carnivores i.e. lion and hyena. Abundance of a subordinate carnivore can be affected by prey availability, ability to avoid dominant carnivore, habitat availability and refuges (Durant 1998, Creel and Creel 1996, Harihar et. al. 2011, Mills and Mills 2014. ...
... In addition to effects on individual movement, competition within the carnivore guild affects population density: spotted hyenas and lions outnumber wild dogs and cheetahs in all relatively intact ecosystems studied to date [15][16][17] . Because low population density reduces gene flow even in the absence of impediments to individual movement 28 , these differences in population density predict a pattern of connectivity opposite to that predicted by the CMC hypothesis. ...
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Large carnivores have experienced considerable range contraction, increasing the importance of movement across human-altered landscapes between small, isolated populations. African wild dogs (Lycaon pictus) are exceptionally wide-ranging, and recolonization is an important element of their persistence at broad scales. The competition-movement-connection hypothesis suggests that adaptations to move through areas that are unfavorable due to dominant competitors might promote the ability of subordinate competitors (like wild dogs) to move through areas that are unfavorable due to humans. Here, we used hidden Markov models to test how wild dog movements were affected by the Human Footprint Index in areas inside and outside of South Luangwa National Park. Movements were faster and more directed when outside the National Park, but slowed where the human footprint was stronger. Our results can be directly and quantitatively applied to connectivity planning, and we use them to identify ways to better understand differences between species in recent loss of connectivity.
... The high density of hyenas, lend some support to our a priori hypothesis that they may have experienced a degree of competitive release, resultant of a decrease in lion density in the QECA (this decrease over a ten-year period is described in Braczkowski et al. 2020). Creel and Creel (1996) (2005) showed spotted hyenas in Etosha National Park, Namibia could not prevent lion stealing their kills, nor could they themselves steal lion kills unless they outnumbered lions by a factor of >3. Watts and Holekamp (2008) showed that lower lion densities (0.079-0.135 lions/km 2 in Amboseli vs 0.44 in the Maasai Mara, as estimated by Ogutu and Dublin (2002) using callup surveys), led to a 24% greater lifetime reproductive success in spotted hyenas in Kenya's ...
Thesis
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Humanity is exerting unprecendented pressure on natural ecosystems and the species living in them. This pressure is particularly evident among the larger members of the order Carnivora. Their large body size (typically in the 25-600 kg range), life history traits, and reliance on large prey species places them at increased risk of extinction. The International Union for the Conservation of Nature (IUCN) Cat Specialist Group, and the Convention of Migratory Species (CMS) both recognize the deficiencies in robust data available on large carnivores across large tracts of Africa. Furthermore, the population estimates we do have are often drawn from less-reliable methods. The overarching aim of this PhD thesis was to: 1) use a recently-developed population estimation technique (Elliot and Gopalaswamy 2017) to estimate the densities, population size, and population parameters of large carnivores in the Queen Elizabeth Conservation Area (QECA), Uganda, and use these data to inform their conservation status, 2) improve understanding of the conflict between large carnivores and human communities in Lake Mburo, Uganda, and Mumbai, India, and 3) explore alternative methods to fund conservation measures, including compensation and a wildlife imagery royalty. In Chapter 1 as part of introducing my thesis, I examined the literature on historic and present methods being used to census African lions Panthera leo and together with a team of international collaborators I made a case for the adoption of spatially explicit capture recapture (SECR) methods for African lions. In Chapter 2 I built upon this and showed the utility of using population state variables (namely movement, sex-ratios, and density) in assessing the conservation status of African lions in a poorly known area of East Africa. I used a population of African lions in south-western Uganda’s Queen Elizabeth Conservation Area (QECA), as a model. I conducted a 93-day African lion census in 2017-2018 and compared the results to those from an intensive radio-collaring study from a decade ago. I hypothesized that if the population of African lions in the QECA was stable or increasing, lion movement distances and home ranges would be similar between the two study periods but if movement distances were larger and sex-ratios were male-biased, the lion population was likely declining. I found male lions expanded their ranges by > 400%, and females >100%, overall lion densities were low (2.70 lions/100 km2, posterior SD=0.47), and the sex ratio of lions in the system was skewed towards males (1 female lion: 2.33 males), suggesting a decline. I concluded this chapter with a discussion of the practical conservation application of using this census technique in other parts of Africa, particularly where historic lion home-range data exist. In Chapter 3, I used the same spatially explicit capture recapture models on data collected from 74 remote camera traps set across the QECA to assess the population densities of African leopards and spotted hyenas in this savannah park. We surveyed the northern, and southern sections of the QECA, and estimated leopard densities to be 5.03 (range = 2.80–7.63), and 4.31 (range = 1.95–6.88) individuals/100 km2 respectively, while hyena densities were 13.43 and 14 individuals/100 km2. Estimates of hyena density were the highest recorded for the species anywhere within their range using SECR methods. I also suggested that the high hyena densities could be related to the evidence provided in Chapter 2 of African lion decline in the QECA. One hypothesis that could explain the inverse densities of hyenas and lions is that hyenas have experienced competitive release from African lions in the QECA. Similar findings have been reported in the Talek region of Kenya’s Maasai Mara, and Zambia’s Liuwa Plains. This chapter also provided the first SECR population estimates of leopards, and spotted hyenas anywhere in Uganda. In Chapter 4 and Chapter 5 I addressed the most important threat to the existence of large carnivores: conflict with human communities, and their livestock. While conflict tends to dominate the narrative where large carnivores and humans co-exist, there can often be direct and indirect benefits to humans. In Chapter 4 I examined the ecosystem services provided to people by the Indian leopard Panthera pardus fusca, in Mumbai.The Sanjay Gandhi National Park (SGNP) is located in the city of Mumbai, India, and has some of the highest human population densities in the world. Large carnivores are known to control prey populations, suppress smaller carnivores, reduce parasite load in humans, and promote seed dispersal. However, this chapter is one of the first studies highlighting the ecosystem services provided by a large carnivore outside of a natural or protected system. I showed that leopard predation on stray dogs reduced the number of people bitten by dogs, reduced the risk of rabies transmission, and reduced dog sterilization and management costs. Our estimates showed that dog densities around SGNP (17.3/km2) were 40 times lower than four nearby urban informal settlements (688/km2) and were ten times lower than the citywide mean (160/km2). If it is, as we propose, leopards that are holding the dog population around the park at its current density, dog bites could increase from 3.6 bites/1000 people to 15.5 bites/1,000 people if leopards were to disappear. As over 78% of dog bites in Mumbai require treatment, and 2% require rabies post-exposure vaccination, the treatment costs could reach as high as US$ 200,000 per year (compared to ~US$ 42,500 currently). As development pressures are threatening the region’s leopards, this work shows the potential costs of their local extirpation. Chapter 5 assesses the landscape-level correlates of livestock attacks by two large carnivores, the spotted hyena, and African leopard in the cattle and sheep/goat farms bordering Lake Mburo National Park, south-western Uganda. I also make suggestions on how to improve the sustainability of a voluntary financial compensation scheme run by a local lodge (the Mihingo Conservation Fund) aimed at alleviating persecution of these species. I used ten years of depredation events to investigate the importance of seasonality and landscape features (ie. terrain ruggedness, proximity to roads, water, human settlements, and vegetation density) on livestock attack probability. I also examined the current costs of the compensation scheme of reported attacks. I showed that most livestock attacks in this region were caused by spotted hyenas, both predators killed at night, did not exhibit seasonal patterns in depredation, and attacks were owed to poorly fortified bomas (82% of leopard attacks and 64% of hyena attacks were made inside bomas). Attacks were also made near human settlements, close to the national park border, and in areas of rugged terrain. The compensation fund made more gross income from tourism activities than was paid in compensation in most years, but compensation costs had to be subsidised by the lodge because the funding was also used in other community development projects (eg. building of a school, and paying children’s school fees). Chapter 6 of this thesis built upon the sub-theme of Chapter 5, funding of carnivore conservation measures and created a roadmap for a recently proposed idea of a threatened wildlife imagery royalty to stem the large budgetary shortfalls facing large carnivore conservation. The idea of a threatened species imagery royalty was proposed in two recent papers, Good et al. (2017) and Courchamp et al. (2018). I built upon these and discussed how such a royalty could be implemented, explored several legal avenues for its application, and also showed its potential scale in leveraging funding. The creation of a national law which charges a royalty from corporations using the imagery of their threatened wildlife, and a “Fairtrade” equivalent held the most promise for the development of a wildlife imagery royalty. Indeed, articles 3 and 6 of the Convention on Biological Diversity (CBD) encourage sovereign states to ensure activities within their jurisdiction and control do not damage the environment of other states. Similarly they are encouraged to develop national strategies, plans or programs for the conservation and sustainable use of biological diversity. The funding that could potentially be leveraged from a wildlife imagery royalty is immense. I used large felids as a model group to show that the relevant 14 companies on the Forbes 2000 list alone could generate US$ 202 million–2.02 billion if they paid 0.1-1% of their profits in royalties. My thesis addressed an important but often overlooked component of estimating large carnivore populations, the use of population state variables in informing conservation status. The use of animal movement, sex-ratio, and density information has wide application that transcends large carnivores. My assessment of leopard-dog interactions, and the potential implications for humans, was one of the first examples in the literature of the potential benefits a large carnivore may have to humans. The assessments of compensation and wildlife imagery royalties have important consequences on better managing and also leveraging funding for the conservation of large carnivores and other threatened, enigmatic species.
... Maintaining larger groups would be advantageous for foraging, breeding, and coexisting with larger predators (Courchamp & Macdonald, 2001). However, in the African savanna ecosystem, the group sizes of subordinate predators such as African wild dogs, and spotted hyenas (Crocuta crocuta) (Creel & Creel, 1996M'soka et al., 2016;Périquet et al., 2015) have been recorded to be inversely related to lion densities. The reduced group sizes in subordinate competitors are an outcome of predation pressure, low recruitment rates, and reduced energy gains due to the inability to guard kills against apex predators (Courchamp & Macdonald, 2001). ...
... Body size also affects interspecific competition. Laboratory and field studies show that competitors with larger body size tend to be superior (Connell 1983;Creel and Creel 1996;Hagelin 2002), although this is not always the case (Persson 1985). Larger body size can increase competitive ability through both direct and indirect mechanisms including interference competition, competitive avoidance, and exploitative competition (Brown and Maurer 1986;Caro and Stoner 2003). ...
Article
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Climate change is creating warmer, earlier springs, which are causing the phenology of many organisms to shift. Additionally, as temperatures increase, the body size of many ectotherms is decreasing. However, phenological and body size shifts are not occurring at the same rates across species, even in species that live in close proximity or have similar life history. Differing rates of phenological and body-size shifts may affect ecological interactions. We investigated whether shifts in phenology and body size had a predictable effect on interspecific competition. We tested three hypotheses. First, priority effects would indicate early arriving organisms gain a competitive advantage. Second, larger organisms would be competitively superior. Third, similarly sized organisms would compete more strongly. We manipulated aquatic larval conditions to create variation in wood frog (Rana sylvatica) size at and date of metamorphosis. Wood frogs were placed in terrestrial enclosures with unmanipulated juvenile American toads (Anaxyrus americanus) where we tracked amphibian growth over 3 months. Consistent with the size superiority hypothesis, initially smaller wood frogs did not compete as strongly with toads. However, the results of the phenological shift were the opposite of our priority effects prediction: early arrival by frogs increased toad mass. Our results could indicate that toads would experience fewer negative effects of competition with wood frogs that metamorphose earlier and smaller under climate change. Our study highlights the challenges of predicting how climate change will affect interspecific interactions and emphasizes the need to investigate the role of shifts in both phenology and body size.
... Africa supports numerous biodiversity hotspots and is home to some of the most diverse terrestrial carnivore communities, where carnivores evolved and adapted to interactions with guild members within large, heterogeneous ecosystems where they roamed freely (Agha et al., 2018;Fedriani, Fuller, Sauvajot, & York, 2000). Africa's large carnivore guild (African wild dogs (Lycaon pictus), cheetahs (Acinonyx jubatus), leopards (Panthera pardus), striped hyaenas (Hyaena hyaena), spotted hyaenas (Crocuta crocuta), brown hyaenas (Parahyaena brunnea) and lions (Panthera leo); Winterbach, Winterbach, Somers, & Hayward, 2013) is unique, as its membership remains largely intact compared to carnivore guilds on other continents (Creel & Creel, 1996;M.W. Hayward & Kerley, 2008). ...
Article
Trophic cascade theories such as the ‘behaviourally-mediated trophic cascade hypothesis’ (BMTCH), have mainstreamed as ecological tools for conserving biodiversity and restoring ecosystems. The BMTCH relies on indirect negative effects of large carnivores through suppression of mesocarnivore activity and habitat use. Importantly, effects of top carnivores on mesocarnivores varies over time and space, is dependent on the species involved, and local context. In South Africa, there are very few free-ranging carnivores, as populations are often restricted to enclosed reserves. While predator-proof fences reduce human-wildlife conflict, they also influence space use within communities. We used an enclosed reserve with a relatively full complement of carnivores to test the generality of the BMTCH in the African context. Using single-species, multi-season occupancy models we investigated the spatial dynamics of multiple carnivores. We also investigated spatial partitioning by vegetation type and temporal partitioning. Our results revealed both support for and against the BMTCH. Lions and spotted hyaenas negatively influenced the detection probability of black-backed jackals and African wildcats, while leopards had a positive effect on these two mesocarnivore species. Additionally, lions positively influenced the detection probability of side-striped jackals. Although space use of carnivores in relation to vegetation type showed minimal evidence of spatial partitioning, each carnivore had a unique combination of abiotic and biotic factors influencing their spatial dynamics, which could facilitate co-existence. Temporal partitioning may also be promoting co-existence as activity patterns of smaller carnivores overlapped the least with sympatric carnivores, particularly lions. Extensive activity overlap between large carnivores does not promote co-existence. We suggest that applying the BMTCH as a universal law across ecosystems is unsupported and may lead to inappropriate conservation and management actions, and prevent protection of ecosystems.
... Wild dogs hunt for~3.5 h per day but would need to increase their hunting activity to 12 h per day to meet energy requirements should they lose a quarter of their food to kleptoparasitism (Gorman et al. 1998). This poses a serious risk to wild dogs, which naturally live in low densities, and show a negative relationship in density as hyena and lion numbers increase (Fanshawe and Fitzgibbon 1993;Creel and Creel 1996;Mills et al. 1998). Wild dogs in KNP lose a large number of kills to kleptoparasitism by spotted hyenas and lions, particularly in open habitats where visibility is good (Kruuk 1972;Fanshawe and Fitzgibbon 1993). ...
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The Kruger National Park (KNP) is home to the last genetically viable, minimally managed population of African wild dogs (Lycaon pictus, wild dogs) in South Africa. Until 2004, this population remained stable, but since has been declining. In this study, we aimed to improve our understanding of the ecology of KNP wild dogs by estimating the relative contribution of different prey types to their diet across landscape types. Based on a Bayesian mixing model, we assessed wild dog diet and foraging preferences using stable isotope analysis. We sampled 73 individuals from 40 packs found in six different landscape types. In thickets, packs predominantly prey on small browsing and mixed-feeding species (accounting for ~73% of their diet), but occasionally hunt large grazers (~24%) and large browsers (~3%). In open landscape types where lions (Panthera leo) are more or less absent, such as in the Lowveld sour bushveld, wild dogs prey on large browsers and large grazers (~67%). Our results demonstrate that KNP wild dogs occupy a broader ecological niche than previously thought, with small browsers forming an integral part of their diet. We also present the first data describing differences in wild dog diet–tissue discrimination factors for tail hair and whiskers compared to respective stable nitrogen (δ15N) and carbon (δ13C) values obtained from feces of captive wild dogs, as well as from those of South Africa’s broader managed metapopulation. While these data should be considered preliminary, we suggest that until wild dog diet–tissue discrimination factors are calculated through a controlled feeding study, the discrimination factors calculated for the gray wolf (Canis lupus) should be used for wild dog-related isotope studies, rather than the often cited values for red foxes (Vulpes vulpes).
... This has been observed across taxa and in a wide array of ecosystems. For example, interspecific interactions affect the space use and distribution of competing raptors (Martínez et al., 2008), sharks (Sabando et al., 2020), seals (Jones et al., 2015), and African savannah carnivores (Creel & Creel, 1996;Durant, 1998). In turn, competition among predators, and the resulting niche differentiation, affects both the population dynamics of their prey (Sinclair et al., 2003) and the demography and behavior of the subordinate competitor (Groom et al., 2017). ...
Article
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Competition between apex predators can alter the strength of top‐down forcing, yet we know little about the behavioral mechanisms that drive competition in multipredator ecosystems. Interactions between predators can be synergistic (facilitative) or antagonistic (inhibitive), both of which are widespread in nature, vary in strength between species and across space and time, and affect predation patterns and predator‐prey dynamics. Recent research suggests gray wolf (Canis lupus) kill rates decrease where they are sympatric with brown bears (Ursus arctos), however, the mechanisms behind this pattern remain unknown. We used data from two long‐term research projects in Scandinavia (Europe) and Yellowstone National Park (North America) to test the role of interference and exploitation competition from bears on wolf predatory behavior, where altered wolf handling and search time of prey in the presence of bears are indicative of interference and exploitation competition, respectively. Our results suggest the mechanisms driving competition between bears and wolves were dependent on the season and study system. During spring in Scandinavia, interference competition was the primary mechanism driving decreased kill rates for wolves sympatric with bears; handling time increased, but search time did not. In summer, however, when both bear and wolf predation focused on neonate moose, the behavioral mechanism switched to exploitation competition; search time increased, but handling time did not. Interference competition, however, did affect wolf predation dynamics in Yellowstone during summer, where wolves prey more evenly on neonate and adult ungulates. Here, bear presence at a carcass increased the amount of time wolves spent at carcasses of all sizes and wolf handling time for small prey, but decreased handling time for the largest prey. Wolves facilitate scavenging opportunities for bears, however, bears alter wolf predatory behavior via multiple pathways and are primarily antagonistic to wolves. Our study helps clarify the behavioral mechanisms driving competition between apex predators, illustrating how interspecific interactions can manifest into population‐level predation patterns.
... Thus, the presence of a larger competitor could limit a species' potential to increase body size as a response to increased food availability. Conversely, species differences in body size response to climate change can affect the competitive interactions of species occupying a similar niche 31,33 . Thus, the presence or absence of similar sized competitors should be considered when studying changes in body size as a potential response to climate warming. ...
Article
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Many species show spatial variation in body size, often associated with climatic patterns. Studying species with contrasting geographical patterns related to climate might help elucidate the role of different drivers. We analysed changes in the body mass of two sympatric medium-sized carnivores—pine marten ( Martes martes ) and stone marten ( Martes foina )—across Europe over 59 years. The body mass of pine marten increased with decreasing latitude, whereas stone marten body mass varied in a more complex pattern across its geographic range. Over time, the average body mass of pine martens increased by 255 g (24%), while stone marten by 86 g (6%). The greatest increase of body mass along both martens’ geographic range was observed in central and southern Europe, where both species occur in sympatry. The body mass increase slowed down over time, especially in allopatric regions. The average pine/stone marten body mass ratio increased from 0.87 in 1960 to 0.99 in 2019, potentially strengthening the competition between them. Thus, a differential response in body size to several drivers over time might have led to an adaptive advantage for pine martens. This highlights the importance of considering different responses among interacting species when studying animal adaptation to climate change.
... Competition is an important structuring force within species assemblages and can impact species distributions (Berger & Gese, 2007), densities (Creel & Creel, 1996), population dynamics (Chesson & Kuang, 2008) and behaviours (e.g. space and time use; Mori, Ferretti, & Fattorini, 2019). ...
Article
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Understanding the mechanisms facilitating coexistence within species assemblages is a key consideration for conservation as intact assemblages are necessary for maintaining full ecosystem function. The African large predator guild represents one of the few remaining functionally intact large predator assemblages on Earth, and as such, represents a unique study system to understand competitive interactions. Yet, relatively little is known of the coexistence mechanisms between some of its intermediately sized members, particularly leopards (Panthera pardus). Here, we use overlapping spatio‐temporal activity and GPS data on lions (Panthera leo), leopards, African wild dogs (Lycaon pictus) and cheetahs (Acinonyx jubatus) to examine spatial interactions and temporal partitioning between leopards and other guild members in northern Botswana. We found that at the population level, male leopard space use and activity patterns were largely unaffected by intraguild competitors. Leopards showed minimal movement coherence with competitors (avoidance or attraction) when moving through areas of home ranges shared with intraguild species. Moreover, we found evidence to support the hypothesis that guild species’ activity patterns are primarily driven by light availability rather than predator avoidance. Our results suggest predator avoidance has a limited impact on broad‐scale leopard spatio‐temporal niches, with aspects of the leopards’ ecology and life history likely facilitating its ability to thrive in close proximity to competitors. Considered alongside other studies, our results suggest that landscape‐level approaches to conservation may be suitable for aiding leopard conservation. The African large predator guild represents one of the few remaining functionally intact large predator assemblages on Earth, and as such, represents a unique study system to understand competitive interactions. Yet relatively little is known of the coexistence mechanisms between some of its intermediately sized members, particularly leopards (Panthera pardus). We used overlapping spatio‐temporal data from African predators to examine spatial interactions and temporal partitioning between leopards and other guild members in northern Botswana. Our results suggest predator avoidance has a limited impact on broad‐scale leopard spatial and temporal niches in our study area.
... Competition with other larger carnivores is another threat to the survival of wild dogs. For instance, the study done by [19] showed that, the density on a 2600-km 2 area of the Selous Game Reserve, Southeast Tanzania was 0.04 adults/km 2 for wild dogs, 0.32 hyenas/km 2 for Spotted hyena (Crocuta crocuta) and 0.11 lions/km 2 for Lion (Panthera leo), and the relationship between wild dogs and either Spotted hyena or lion was negative. This leads to overlapping in terms of diet in wild dogs and these other species. ...
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African Wild dog (Lycaon pictus) population has been observed declining at high pace regardless of many conservation efforts done. This paper aimed at pointing out the threats which catalyse the decline of this endangered species and provide some mitigation measures. Among others, habitat destruction, diseases, human-wild dog conflicts and interspecies competition were observed to be among the threats which accelerate the decline of Wild dog population. It is recommended that health welfare of wild dogs such as mass domestic dog vaccination against Rabies, parvo, Canine distemper virus need to be addressed. Also participation of local communities on the conservation of Wild dogs is essential. Furthermore, provision of conservation education, implementation and enforcement of conservation laws together with involvement of different stakeholders were identified to be essential for the survival of the species. Keywords: Challenges, Conserving, Endangered Wild Dog
... Complex interactions between coexisting jaguars and pumas are related to their habitat and prey use (Woodroffe, 2001;Scognamillo et al., 2003;Foster et al., 2010aFoster et al., , 2010bSollman et al., 2012). Evidence to support this includes their differential use of vegetation, particular densely vegetated habitats (Hanski, 1994;Creel and Creel, 1996;Durant, 1998;Fedriani et al., 1999;Maffei et al., 2004;Chávez, 2010;Di Bitetti et al., 2010;Foster et al., 2013) and temporal differences that facilitate evasion (Aranda and Sánchez-Cordero, 1996;Romero-Muñoz et al., 2010) such as different activity regimes to help avoid conflict (Paviolo et al., 2009;Di Bitetti et al., 2010;Foster et al., 2013;Hérnandez-Saint Martín et al., 2013;Àvila-Nàjera et al., 2016). Examples of dietary specialization include the dominant species -usually considered to be the jaguar (Sollman et al., 2012)selecting larger prey, and changes to niche breadth seen from differential prey selection by size, age and taxa (Gittleman, 1985;Aranda, 1994;Karanth and Sunquist, 1995;Aranda and Sánchez-Cordero, 1996;Taber et al., 1997;Karanth and Nichols, 1998;Núñez et al., 2000;Scognamillo et al., 2003;Chávez, 2010;Di Bitetti et al., 2010;Foster et al., 2013). ...
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The biological ranges of the jaguar (Panthera onca) and puma (Puma concolor) overlap in the Yucatan Peninsula, corresponding to the most important population of jaguars in Mexico. The goal of this study in the El Eden Ecological Reserve (EER) was to investigate the factors that permit these two predators to coexist in the dense vegetation of medium–stature tropical forest and secondary forest in the north–eastern Yucatan Peninsula. We assessed their spatial and temporal overlap using Pianka’s index, and evaluated their habitat use by applying occupancy models. A total sampling effort of 7,159 trap–nights over 4 years produced 142 independent photographic records of jaguars, and 134 of pumas. The felids showed high to very high overlap in their use of different vegetation (0.68–0.99) and trail types (0.63–0.97) and in their activity patterns (0.81–0.90). However, their peak activity patterns showed some temporal separation. Time of day, particularly for peak activity time, was the best predictor to explain the coexistence of the felids in this habitat. While occupancy models showed that the presence of potential prey species and vegetation type could predict the presence of felids in the study area. Natural disturbances during 2010 (hurricane) and 2011 (fire) drastically changed habitat use and activity patterns, resulting in pumas and jaguars adjusting their resource–use and activity pattern through a strategy of mutual evasion.
... This competition from spotted hyaena as well as lion (Panthera Leo) is a major driver in their movement patterns and times of activity, something that is exacerbated in fenced reserves (Darnell et al. 2014). It also impacts upon prey selection and time spent on a kill (Carbone et al. 1997), with lions responsible for the largest form of natural mortality in wild dog's avoidance behaviours are common (Van Herdeen et al. 1995;Creel & Creel 1996 (Woodroffe & Ginsberg 1999), consequently, reducing available habitat is likely to impact upon the size, sex and species of prey caught, as well as increasing the proportion of kills along reserve edges. Current research suggests, packs spend more time on the fence boundary in the first few months after reintroduction, than when settled (Van Dyk & Slotow 2002) increasing the chance of fences being used in hunting during this period but also increasing the chance of a break out from a reserve. ...
Thesis
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The proliferation of African wild dog reintroductions in fenced reserves is widely regarded to have been a successful conservation intervention. Despite this, research suggests that the presence of wild dogs in fenced areas can alter the species ecology, in particular, foraging. Evaluating the significance and causes of these changes is critical for understanding how wild dog populations can be managed and conserved in small fenced reserves. The use of fences when capturing prey is widely cited in literature yet very few papers have studied it. Using data collected from the daily monitoring of wild dogs from two reserves in South Africa, one in the presence of lions (Manyoni) and one without (Somkhanda), the use of fences by reintroduced wild dog packs were analysed. The results of this study showed at Manyoni kills within 10m and between 11-100m of the reserve boundary were significantly more frequent than at greater distances, while at Somkhanda although areas closer to the boundary positively correlated with kills, it was not significant. Results also indicated that interspecific competition was a major driver to consider in relation to this behaviour, with overall kill zones far more evenly distributed throughout Somkhanda when lions were absent. Events, such as mortality during the study period, meant the settling period post-release could not be concluded to be a factor, while denning appeared to have little impact on foraging behaviour. Medium-sized ungulates made up the majority of the diet in both reserves, while no preference was shown for hunting larger prey at the boundary edge. The distribution of all primary prey species were negatively associated with areas near to the fence boundary, indicating the presence of potential prey was not likely to be a driver of this behaviour It has been concluded in previous literature that an improved chance of capture success is the main driver for the increased frequency of successful hunts on reserve boundaries, however, these results indicate that it is a very complex set of factors that might be driving it, in particular, competition. The difference in results between the two packs highlights that care needs to be taken when generalising results even with populations in similar environments, due to the many complex drivers that influence the behaviour of wild dog packs.
... Entre los perros salvajes (Lycaon pictus, Brookes) la competencia por interferencia se establece con otros carnívoros como las hienas, los nichos de ambas especies muestran alto solapamiento (Fig. 2) cuando ésta última tiene poblaciones densas (Creel y Creel, 1996). Figura 2. Las dos áreas en forma de cuadrado representan la utilización de recursos por dos especies en una comunidad. ...
Book
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This is a review about the main ecological interactions, it was written to help Biology Students at University of Gudalajara
... Leopards abundance was higher compared to other two carnivores i.e. lion and hyena. Abundance of a subordinate carnivore can be affected by prey availability, ability to avoid dominant carnivore, habitat availability and refuges (Durant 1998, Creel and Creel 1996, Harihar et. al. 2011, Mills and Mills 2014. ...
Article
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Data pertains to abundance and habitat use on patch scale on large mammals was collected using camera trapping during summer 2017. Camera traps were placed systematically in a 4 km grid in an area of 200 km. Relative Area Index was used as a measure 2 2 of relative abundance of mammals and frequency of occurrence of different species in different habitat as a measure of habitat use. Difference among habitat use was tested using chi-square test. A total effort of 1581 trapping days resulted from four months of camera trapping. Among herbivores chital was the most abundant and distributed on the basis on RAI followed by sambar, wild boar and nilgai. Among carnivore's leopards was the most distributed and abundant carnivore followed by the lion and hyena. Except hyena and wild boar all other species use habitat differentially. Chital mostly use Teak-Acacia-Zizyphus habitat while sambar use Teak-Mixed habitat most. Nilgai use Mix Valley habitat most while wild boar uses all habitats equally. Leopards and lion use riverine habitat more while hyena use all habitats equally. Prey habitat use is discussed in the light of foraging, predation and abiotic factors in habitat patches while predator habitat use was discussed in light of food availability, competitor avoidance, human disturbance and abiotic factors. Relative abundance was discussed in light of present and earlier conservation efforts in Gir, and other ecological conditions affecting the abundance such as food availability and coexistence among carnivores.
... Methodology: This method is widely used for social carnivores that utilize long-range vocalizations to communicate (McCarley 1975, Harrington & Mech 1982, Creel & Creel 1996, Jaegeret al. 1996 and it is the most common and effective with golden jackal. The area of interest is covered by randomly placed calling stations at an average linear distance of 2 km, which is the average breeding female territory (Giannatos et al. 2005). ...
... Esta distribución espacial de las especies cambia si se considera el escenario E3; la atracción del superdepredador hacia el recurso favorece que el meso depredador tienda a ocupar espacios distintos al del superdepredador, el cual se concentra en los sitios de mayor densidad del recurso. En la naturaleza, un ejemplo que no es completamente análogo al caso E3, porque no hay un volátil (aparentemente) de por medio, pero en términos del patrón espacial es parecido, ha sido observado con los guepardos (Acynonyx jubatus) y los perros salvajes africanos (Lycaon pictus), los cuales evitan las áreas con alta densidad de presas porque estas son sitios donde competidores y superdepredadores, como las hienas manchadas (Crocuta crocuta) y los leones (Panthera leo), alcanzan densidades poblacionales altas (Laurenson, 1994;Creel y Creel, 1996; Mills y Gorman, 1997). ...
Article
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Understanding mechanisms and processes that determine the distribution and abundance of species as well as biodiversity patterns over time are one of the most interesting and challenging problems in Ecology, and particularly in Biogeography. Although in scientific literature diverse theoretical bodies have been proposed to explain these mechanisms, the formalization of how fundamental ecological processes (physiology, behavior, demography, and dispersal) and the spatial patterns of biodiversity are related is a field that remains in continuous development. In this work, we describe some of the relevant problems that arise from modeling the ecological niche and the spatial distribution of biodiversity. These problems include the theoretical conceptualization of the relationship between fitness attributes and the ecological niche, the effect of biotic interactions, dispersal and, defense mechanisms on the spatial distribution of a set of species that share a given environment. Results of various analyzes obtained by the authors in the study of these problems with the use of mathematical modeling are shown
... African wild dogs are restricted to den sites for approximately 3 months during a seasonal breeding period (Creel and Creel 1996). Denning is a vulnerable period during which a high percentage of the pack may consist of dependent young, and packs must return daily to the den to provision the pups by regurgitation (Creel and Creel 2002). ...
Article
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Many species rear offspring in fixed sites, returning frequently to provision them, and the selection of these sites is a critical decision in the life cycle, as they may in some instances increase susceptibility to predators. African wild dogs are a groupliving large carnivore that rear their offspring in fixed sites, provisioning dependent pups in dens for 3 months post-birth. Where possible, African wild dogs select den sites in rocky terrain, and it is hypothesised that this is because lions, their main predators, generally avoid this habitat. In the Okavango Delta, Botswana, there is a lack of rocky terrain, providing an opportunity to assess whether lions drive den site selection. GPS collar data from 7 impala and 4 lions revealed that both species prefer to reside in grassland and mixed woodland habitats, demonstrating that these are high risk/reward areas for African wild dogs. Using GPS collar data from 16 African wild dog packs over 8 years, our study characterised 116 African wild dog den sites identified in the field. Packs showed a preference for denning in mopane woodland, which lions avoid, and packs commuted further from the den each day as the den’s distance to grassland and mixed woodland increased, suggesting a preference for hunting in this habitat. Our results suggest that African wild dogs trade-off the costs of commuting and predation risk, such that longer commuting costs confer increased safety. Significance statement Species which utilise dens, nests, or other fixed sites to rear offspring must balance the need to protect their young from predators with the need to acquire resources for themselves and their young. The selection of den sites is expected to be of considerable importance to enable the animal to meet these two requirements and successfully raise young. Our study of African wild dogs indicates that they select dens in resource-scarce areas which are likely to minimise interactions with their main predator, lions. This increases the distance to prey-rich areas and therefore the cost of hunting. Availability of appropriate habitat for both hunting and denning is therefore important when considering landscapes appropriate for African wild dog conservation, energetic constraints of breeding, and home-range indices.
... Historically, the species was once distributed across the African continent, absent only from the jungles and deserts (Woodroffe 2004;. Today, wild dogs remain uncommon even in essentially less disturbed wilderness, apparently due to negative interactions with larger carnivores and livestock predation (Creel and Creel 1996;Mills and Gorman 1997;Woodroffe et al. 2005). ...
Article
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Masenga E, Hasan SN, Japhet K. 2018. Abundance, distribution, and conservation threats of African wild dog (Lycaon pictus) in the Loliondo Game Controlled Area, Tanzania. Asian J For 2: 31-41. Assessment of abundance, distribution, and conservation threats to African wild dogs was conducted in Loliondo Game Controlled Area (LGCA), northern Tanzania. Specifically, the study focused on determining population size and structure, spatial distribution, attitudes of local people towards wild dogs and wild dog conservation and threats impacting the species. Semi-structured interviews, diurnal random searches, internal and external examinations of wild dogs carcasses examined, and night transect surveys were employed. Eight packs with a total of 132 recognized individuals at an average pack size of 16.50 ± SD 7.50 individuals were recorded. Pack sizes 3 individuals were reported to be sighted mostly and of all respondents (n= 210), only 26% were able to recognize wild dog sexes. The density of both known and unknown wild dogs was 0.19 animals/km2, higher compared to other carnivores. In terms of distribution, most of the packs were concentrated in the northern part as compared to the central and southern parts of LGCA. The species was observed to occur most in woodland type of vegetation. Interestingly, 55.30% of respondents showed a positive attitude towards wild dogs and wild dog conservation despite that 52.90% of respondents dismissed lack of any conservation action or strategy in place towards conserving the species. However, poisoning and Canine Distemper Virus were identified as the main threats. Therefore, conserving African wild dogs in LGCA requires mult-approach conservation efforts (i.e. awareness rising to community, fitting radio telemetry to the dogs and threats management interventions) due to nature of the species.
... These interactions can ultimately lead to a reduction in abundance or a change in behaviour of the smaller predator so that encounters with the larger predator are minimized. For example, African wild dogs are kept at low densities by competition with hyenas and by competition and predation from lions (Creel and Creel 1996); while mongooses and genets have been shown to avoid areas used by Iberian lynx which are known to harass and occasionally kill them (Palomares et al. 1996). ...
Thesis
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This thesis explores evidence for top-down suppression of an exotic mesopredator, the feral cat Felis catus (L.), by a native apex predator, the dingo Canis dingo (Meyer) in an arid environment in Australia. I investigate this topic by examining the spatial dynamics of feral cat and dingo distributions and activities and by examining the potential for competition between them for shared prey. By analysing both spatial and dietary dimensions of dingo and feral cat interactions my research allows for a very detailed characterization of this intraguild relationship. Apex predators may suppress smaller ‘mesopredators’ through direct antagonistic interactions or through indirect competition for resources. These interactions may result in a reduction in mesopredator abundance or changes in their behaviour causing them to avoid apex predators. In Australia, the dingo is the continent’s top terrestrial predator and co-occurs with the introduced mesopredator, the feral cat. Feral cats prey on native species and are implicated in the extinction of at least 16 mammals; reducing the impacts of feral cats is crucial for the conservation of Australian fauna. As the dominant apex predator, dingoes are predicted to suppress the activity and/or abundance of feral cats. However, definitive evidence supporting this hypothesis remains scant and insufficient. Understanding the influence of apex predators on sympatric predators and prey requires reliable and accurate estimates of their distribution and activity. I assessed the effect of camera trap survey design on the detection of dingoes, feral cats, and macropods and used occupancy models to examine how habitat influences the occurrence of these species. The detection of dingoes and cats, but not, macropodids (Macropus spp.), was improved when cameras were placed on roads. Occupancy estimates of dingoes and macropodids were significantly higher in woodlands compared to grasslands while feral cats exhibited near-equal occupancy in both habitats. These results show that robust occupancy estimates can be obtained from cameras placed on roads and suggest that dingoes prefer woodlands, probably due to the presence of their main prey (macropodids), while feral cat habitat use in this system may not be strongly influenced by the presence of dingoes. Strong dietary overlap can indicate a likelihood of interspecific competition between predators and the potential for mesopredator regulation. However, uncertainty in the identification of scat donor species has the potential to obfuscate these relationships. I assessed the extent of dietary overlap between dingoes and feral cats from field collected scats and developed a new framework to identify and resolve potential errors in scat identifications. Dingoes and feral cats exhibited low dietary overlap, suggesting that interspecific competition between the two predators is low and that a segregation of diets facilitates their spatial coexistence. At the same time, the occasional occurrence of cat remains in the scats of dingoes indicates the potential for interference competition between the two species and demonstrates intraguild predation of the latter on the former. Hence, while dingo and feral cat dietary overlap is low; this could be the end result of competition between the two species. Understanding how predators use space and select features in the landscape can be important for informing the management of non-native mesopredators. I used telemetry data from dingoes and feral cats to characterize their space use and investigate patterns of fine-scale habitat selection. Dingoes showed a strong selection for woodlands whereas feral cats selected vegetation type randomly but their seasonal home ranges typically included a larger proportion of grassland than would be expected from its availability. Both predators showed a strong selection for roads, hydrological features and high vegetation cover. These results suggest that both predators select for many common features in the landscape but may prefer different habitat types which could limit the extent of their interactions. In summary, I was unable to find strong evidence for dingo suppression of feral cats in this study system. Low dietary overlap between the two species suggests limited interspecific competition which may also facilitate their observed spatial overlap. Feral cats may show a preference for grasslands but whether this is driven by avoidance of dingoes or by the occurrence of other resources such as prey warrants further investigation. This thesis contributes to the conceptual development of top-down ecology and increases the understanding of how apex predators and smaller mesopredators relate to one another in their environment.
... Recent studies have demonstrated the extent to which top predators can shape ecosystems due to the strong interactions they have with other species (Estes et al. 2011;Ripple et al. 2014). The most conspicuous effects top predators have on ecosystems are the suppressive and aversive 'direct' effects that they have on populations and behaviour of their prey and smaller predators (mesopredators) that result from killing, the fear they instil and, in the case of mesopredators, competition for resources (Creel and Creel 1996;Schmitz 2008;Brook et al. 2012). In some instances top predators can also facilitate smaller predators through carrion provisioning (DeVault et al. 2003;Sivy et al. 2018) and this can, in some cases, offset the net effect of suppression (Wilson and Wolkovich 2011). ...
Article
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The mesopredator release hypothesis predicts that abundance of smaller predators should increase in the absence of larger predators due to release from direct killing and competition. However, top predators’ effects on mesopredators are unlikely to operate in isolation but interact with other factors such as primary productivity of the landscape and human activities. We investigate factors influencing activity indices of a top predator (dingo) and an introduced mesopredator (red fox) in forests of south-eastern Australia. We used generalised linear models to investigate the effects that net primary productivity, proximity to freehold land and poison baiting campaigns directed at dingoes had on fox and dingo activity. Baiting was the best predictor of activity for both dingoes and foxes. Dingo activity was variable but typically lower at baited sites. Fox activity varied within a lower range at a majority of sites compared to the dingo but was typically higher at the baited sites. Positive responses of foxes to dingo control are consistent with the mesopredator release hypothesis and suggest in this region dingoes may have greater suppressive effect on fox populations than poisoning campaigns directed towards dingoes. Our results suggest that removal of dingoes may be counter-productive for biodiversity conservation because it may lead to higher activity of foxes.
... Interspecies competition can be used as an indicator of carnivore species diversity [3,[63][64][65]. The significant correlation between lion, leopard, spotted hyena, cheetah, wild dog, and other carnivores indicated shared habitat use; however, the correlation varied between weak and fair among the different species combinations. ...
Article
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South African protected areas account for 8% of the total landmass according to World Bank indicators. Effective conservation of biodiversity in protected areas requires the development of specific reserve management objectives addressing species and disease management. The primary objective of the current study was to identify predictors of carnivore detection in an effort to inform carnivore species management plans on Andover and Manyeleti nature reserves in South Africa. A limited number of camera traps were placed randomly using a grid system. Species detection data were analysed using mixed-effects logistic regression and Spearman’s correlation coefficients. Deterministic inverse distance weighted distribution maps were used to describe the spatial distribution of carnivore species. Camera traps identified similar species as traditional call-up surveys during the study and would be useful as an adjunct census method. Carnivore detection was associated with several variables, including the presence of specific prey species. The measured intra-and interspecies interactions suggested the risk of disease transmission among species, and vaccination for prevalent diseases should be considered to manage this risk.
... Maintaining larger groups would be advantageous for foraging, breeding, and coexisting with larger predators (Courchamp & Macdonald, 2001). However, in the African savanna ecosystem, the group sizes of subordinate predators such as African wild dogs, and spotted hyenas (Crocuta crocuta) (Creel & Creel, 1996M'soka et al., 2016;Périquet et al., 2015) have been recorded to be inversely related to lion densities. The reduced group sizes in subordinate competitors are an outcome of predation pressure, low recruitment rates, and reduced energy gains due to the inability to guard kills against apex predators (Courchamp & Macdonald, 2001). ...
Article
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In multipredator systems, group sizes of social carnivores are shaped by the asymmetric intraguild interactions. Subordinate social carnivores experience low recruitment rates as an outcome of predation pressure. In South and Southeast Asia, the Tiger (Panthera tigris), Dhole (Cuon alpinus), and Leopard (Panthera pardus) form a widely distributed sympatric guild of large carnivores, wherein tigers are the apex predators followed by dhole and leopard. In this study, we attempted to understand the variation in pack size of a social carnivore, the dhole, at two neighboring sites in the Central Indian landscape. We further evaluated local‐scale patterns of variation in pack size at a larger scale by doing a distribution‐wide assessment across the dhole ranging countries. At the local scale, we found an inverse relationship between the density of tiger and pack size of dhole while accounting for variability in resources and habitat heterogeneity. Larger dhole packs (16.8 ± 3.1) were observed at the site where the tiger density was low (0.46/100 km²), whereas a smaller pack size (6.4 ± 1.3) was observed in the site with high tiger density (5.36/100 km²). Our results for the distribution‐wide assessment were concordant with local‐scale results, showing a negative association of pack size with the tiger densities (effect size −0.77) and a positive association with the prey abundance (effect size 0.64). The study advances our understanding to answer the age‐old question of “what drives the pack size of social predators in a multipredator system?” This study also highlights the importance of understanding demographic responses of subordinate predator for varying competitor densities, often helpful in making informed decisions for conservation and management strategies such as population recovery and translocation of species.
... The competition between species with analogous ecological requirements tends to decrease through changes in the use of trophic, temporal and spatial resources (Schoener, 1983). The coexistence of sympatric carnivores showing analogous morphology and hunting strategies relies on space segregation (Palomares et al., 1996;Creel and Creel, 1996) and on adjusting activity patterns (Karanth and Sunquist, 2000;Arjo and Pletscher, 1999). ...
... The competition between species with analogous ecological requirements tends to decrease through changes in the use of trophic, temporal and spatial resources (Schoener, 1983). The coexistence of sympatric carnivores showing analogous morphology and hunting strategies relies on space segregation (Palomares et al., 1996;Creel and Creel, 1996) and on adjusting activity patterns (Karanth and Sunquist, 2000;Arjo and Pletscher, 1999). ...
... Lion spatial data. Lions pose the largest natural threat to wild dogs through direct interference competition [33,44,52,88] that can limit wild dog populations [44,53] or even contribute to local extirpation [57,89]. GNP has a recovering and growing population of lions [25]. ...
Article
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Large carnivores have experienced widespread extirpation and species are now threatened globally. The ecological impact of the loss of large carnivores has been prominent in Goron-gosa National Park, Mozambique, after most were extirpated during the 1977-92 civil war. To remedy this, reintroductions are now being implemented in Gorongosa, initiating with endangered African wild dogs (Lycaon pictus), hereafter 'wild dogs'. We describe the first transboundary translocation and reintroduction of founding packs of wild dogs to Gorongosa over a 28-month study period and evaluate the success of the reintroduction based on five key indicator categories. We also assess how wild dog space use and diet influenced their success. We found that pre-release, artificial pack formation in holding enclosures aided group cohesion and alpha pair establishment. Post-release, we also observed natural pack formations as a result of multiple dispersal events. Founder and naturally formed packs produced pups in two of the three breeding seasons and packs successfully recruited pups. Survival rate for all wild dogs was 73% and all mortality events were from natural causes. Consequently, the population grew significantly over the study period. All indicators of success were fully achieved and this study documents the first successful reintroduction of wild dogs into a large, unfenced landscape in Mozambique and only the second on the continent. Potential mechanisms underlying these early successes were the avoidance of habitats intensively used by lions, dietary partitioning with lion, avoidance of human settlements, and Gorongosa's management strategy. We predict further population expansion in Gorongosa given that 68% of the park is still unused by wild dogs. This expansion could be stimulated by continued reintroductions over the short-to medium-term. Recovery of wild dogs in Gor-ongosa could aid in the re-establishment of a larger, connected population across the greater Gorongosa-Marromeu landscape.
... Dominant intra-guild competitors can impose ecological and behavioural constraints on subordinate intra-guild species (Broekhuis et al. 2013;Creel & Creel 1996;Durant 1998;Vanak et al. 2013). We hypothesize here that the absence of dominant competitors can result in the release of sub-ordinates from such constraints, the result of which can be manifest in space use patterns, sociality and prey selection. ...
Conference Paper
The Sri Lankan leopard (Panthera pardus kotiya) is an endangered genetic sub-species that has been without intra-guild competition for thousands of years. If typical leopard ecology is partly due to the influence of intra-guild competition, this unique evolutionary scenario in Sri Lanka suggests leopards might be expected to display different ecological adaptations and behavioural characteristics from populations where intra-guild competition is present or its absence recent. Specifically, due to decreased competitive restrictions, the leopard might be expected to occur in higher densities and occupy smaller home ranges; be less nocturnal and less solitary in its activities; and preferentially prey on larger, more optimal species. We investigated these questions in Block I of Yala National Park, Sri Lanka using extensive direct observations supplemented by spoor analysis to estimate leopard population, range size and behaviour; scat and carcass analysis to determine diet; and comprehensive road transects to understand prey availability and preference. Spatially explicit capture-recapture models indicate an adult resident population of 12.1/100 km2. Adult male home range size (N = 3) averaged 22.5 km2 with extensive overlap whereas adult female core ranges (N = 4) were small (1.6 km2) and exclusive. Population density and adult male range sizes were not significantly different from populations with intra-guild competitors and instead scale well with available prey biomass. The probability of observing a leopard was higher during nocturnal and crepuscular periods than diurnally and activity level was significantly higher during nocturnal sightings than either other period. Most observed leopards were solitary (84.2%, N = 247), but combined with other observational studies in Sri Lanka, lone leopards were observed significantly less than comparable studies with intra-guild competition (X2 = 29.2, P <0.0001). Spotted deer (Axis axis) formed the majority of leopard diet in Yala (91.3% of scats) included in proportion to availability, whereas sambar (Rusa unicolor), comprised a small portion of total diet (3.2%), but were preferentially selected. In summary, Sri Lankan leopard spatial ecology appears influenced by available prey biomass more than the absence of intra-guild competition, however evidence suggests that this lack of intra-guild competition may result in altered behaviour in terms of decreased secrecy and larger prey choice.
... In Africa the complexity of the carnivores' guild promoted substantial prior researches focused on the interactions involving different wild canids, as the spotted hyena (Crocuta crocuta) and the African wild dog (Lycaon pictus), and other larger species, the lion (Panthera leo) above all (e.g. [9][10][11][12]). Regarding Eurasia, many studies dealing with canids interactions focused on a single (or a few) niche dimension ( [13][14][15][16][17], but see [18]). ...
Article
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Background Two coexisting species with similar ecological requirements avoid or reduce competition by changing the extent of their use of a given resource. Numerous coexistence mechanisms have been proposed, but species interactions can also be aggressive; thus, generally a subordinate species modifies its realized niche to limit the probability of direct encounters with the dominant species. We studied niche partitioning between two sympatric wild canids in north-eastern Italy: the golden jackal and the red fox, which, based on competition theories, have a high potential for competition. We considered four main niche dimensions: space, habitat, time, and diet. Results We investigated three study areas monitoring target species populations from March 2017 to November 2018 using non-invasive monitoring techniques. Red fox presence was ascertained in every study area, while golden jackal presence was not ascertained in one study area, where we collected data regarding wolf presence. Considering the two target species, we observed partial diet partitioning based on prey size, with the golden jackal mainly feeding on wild ungulates and the red fox mainly feeding on small mammals. The two canids had an extensive temporal overlap along the diel cycle, having both predominant crepuscular and nocturnal activity patterns, but marked spatial partitioning and differential use of habitats. The golden jackal proved to be specialist concerning the habitat dimension, while the red fox resulted completely generalist: the former selected less human-modified habitats and avoided intensively cultivated lands, while the latter was present in all habitats, including intensively cultivated lands. Conclusions The observed partitioning might be due partially to some ecological adaptations (e.g. specialist vs. generalist use of resources) and specific behaviours (e.g. cooperative vs. solitary hunting) and partially to the avoidance response of the red fox aimed at reducing the probability of direct encounters with the golden jackal.
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Loggerhead sea turtles (Caretta caretta) are currently listed as vulnerable, with a decreasing population trend, by the International Union of Conservation of Nature. From 2015 to 2019, coyotes (Canis latrans) depredated 24.12% of loggerhead nests on the night they were laid on South Island beach at the Tom Yawkey Wildlife Center, near Georgetown, SC, resulting in an estimated 3,816 eggs lost each year. Over that time, a South Carolina Department of Natural Resources Turtle Technician Team patrolled the beach at dawn every morning to cage and catalog loggerhead nests and eggs but were unable to cost-effectively protect the nests the night the eggs were laid. To test a new method to dissuade coyote depredation, we used dispensers filled with gray wolf (Canis lupus) urine to simulate wolf activity on seven sections of the beach and left seven sections untreated as controls. We observed a significant reduction in depredation rates where urine was present relative to control areas (G-test adjusted with the Williams correction, G=5.749, df=1, p=0.0165). The results suggest this may be an example of exploitative competition in the absence of interference competition. With daily teams already patrolling the beaches, using wolf urine as a deterrent could be an inexpensive, non-invasive way to reduce coyote depredation on loggerhead and other sea turtle nests elsewhere.
Conference Paper
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Cánidos y félidos coexisten en gran parte de su rango de distribución. Sin embargo, se desconocen muchos aspectos de su interacción a nivel comportamental, dada la dificultad de realizar este tipo de observaciones. En la Cordillera Cantábrica (NO España), tanto zorros como gatos monteses hacen uso de los prados destinados al pastoreo y la siega como lugar de alimentación (principalmente centrado en la rata topera (Arvicola scherman)), lo cual facilita el encuentro e interacción entre ambas especies; así como su observación al tratarse de espacios abiertos. En la presente comunicación se muestran y discuten varios casos de interacciones zorro-gato montés en este escenario. Entre los años 2012 y 2019, se han realizado 592 observaciones de gato montés y obtenido más de 30 h de grabación. En 14 ocasiones se han podido observar interacciones zorro-gato (i.e., presencia de ambas especies en el mismo prado). Además, hemos obtenido 8 observaciones de interacciones de colaboradores. Hemos considerado las persecuciones directas y/o el contacto físico como “Agresividad” por parte del perseguidor; sentarse, agazaparse, erizarse, erguirse y seguir con la mirada como “Defensas” por parte del recipiente y por último, miradas o acercamientos lentos como “Curiosidad”. En el 45,45% de los casos el zorro inició el acercamiento y en el resto no se presenció acercamiento claro. Los gatos monteses nunca iniciaron el acercamiento. Los zorros ignoraron a los gatos en el 50% de los casos, huyeron el 22,7%, fueron agresivos en 3 casos, curiosearon en 2 y mostraron comportamientos defensivos en 1 solo caso. Los gatos monteses por su parte se defendieron el 41% de las veces, ignoraron a los zorros el 31,8%, y huyeron el resto de los casos. Nunca agredieron o curiosearon. Tanto el gato montés como el zorro resultaron vencedores (i.e., permaneció en el prado) el 22,7% de los casos respectivamente, aunque la tolerancia fue clara en el 40,9% de los encuentros. Los zorros parecen mostrar un comportamiento más curioso y activo ante la presencia de los gatos monteses, mientras que los gatos suelen reaccionar al encuentro con una estrategia defensiva.
Article
Interspecific aggression has important fitness consequences across the animal kingdom and can be especially important during species invasions, where asymmetric interactions between native and invasive species can lead to native species declines. We investigated the immediate behavioural consequences of interspecific interactions for a native species, the green anole lizard, Anolis carolinensis, after an invasion by a closely related invasive species, the Cuban brown anole, Anolis sagrei. We housed captive populations of green anoles (6 males, 6 females) in large outdoor enclosures and recorded their display behaviours (displays/min), activity levels (movements/min) and habitat use (2D and 3D home range size, perch height) for 10 days. We then introduced brown anoles and recorded the green anoles' behaviours for another 10 days, seeking differences between pre- and post-invasion behaviours. We recorded behavioural interactions between individuals (i.e. headbob and dewlap displays, chases, mating attempts, fights and copulations) throughout the study. To serve as a density control, we duplicated the experiment in a second enclosure using green anoles as ‘invaders’. We performed the experiment eight times with two densities of invaders: high (4 males, 4 females) and low (2 males, 2 females). We found that green anoles have smaller two-dimensional and three-dimensional home ranges and higher average perch heights after invasions but that these changes resulted from increased population densities rather than aggression from brown anole invaders. Furthermore, although green and brown anoles did display to each other, both species preferentially interacted with conspecifics and escalated aggressive behaviours between the two species (e.g. lock-jawed fights) rarely occurred. Taken together, these findings indicate that high brown anole population densities, rather than direct interference competition, could be driving green anole displacement across the brown anole's invasive range.
Article
The presence of Cuon alpinus in Poland is documented here for the first time. Between 650 and 450 ka, Lycaon lycaonoides dominated the open lands, while Cuon alpinus priscus tended to prefer forests, mountains and highlands. Canis mosbachensis coexisted in all these environments. Between 480 and 430 ka, there was a drastic reduction in the number and range of L. lycaonoides. The balance between canids was disturbed and a critical point in the lycaon–wolf relationship was passed. Probably between 450 and 400 ka, the lycaon was too rare to be a real competitor and a limiting factor for the wolf. It was also at this time that the lycaon disappeared completely. With disappearance of the lycaon from Eurasia, there was a slow increase in the body size of the wolf. Between 400 and 300 ka, the dhole and the wolf were still close in body size, but the wolf was slowly increasing in size. Between 300 and 250 ka, the wolf became the dominant dog species and took a niche occupied until then by the lycaon. Because of competition, C. alpinus decreased in body size and adapted to hunting and living in forest, mountain and highland environments.
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Felids and canids coexist along their ranges worldwide. Various interactions can occur between these carnivores, with multiple consequences such as demographic changes of competitors, or behavioural modifications in the use of the spatial, temporal or trophic niches. European wildcats (Felis silvestris silvestris) and red foxes (Vulpes vulpes) coexist across Europe using multi-use landscapes when hunting rodents. They commonly use open fields during the day in the Cantabrian Mountains (NW Spain). We collected 597 diurnal phenotypic wildcat observations between 2012 and 2019, during which we observed 14 encounters (2.34%) of wildcats and foxes. We compiled 11 more encounters from collaborators. Diurnal encounters between both species seem to be rare, which could result from the two species displaying active avoidance. During the encounters, foxes mainly showed offensive behaviours whereas wildcats showed a defensive intimidation strategy, probably in relation to their morphology. Both strategies were equally effective for maintaining the position in feeding grounds.
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Among species, coexistence is driven partly by the partitioning of available resources. The mechanisms of coexistence and competition among species have been a central topic within community ecology, with particular focus on mammalian carnivore community research. However, despite growing concern regarding the impact of humans on the behaviour of species, very little is known about the effect of humans on species interactions. The aim of this review is to establish a comprehensive framework for the impacts of human disturbance on three dimensions (spatial, temporal and trophic) of niche partitioning within carnivore communities and subsequent effects on both intraguild competition and community structure. We conducted a systematic review of the literature on carnivore niche partitioning (246 studies) and extracted 46 reported effects of human disturbance. We found evidence that human disturbance impacts resource partitioning, either positively or negatively, in all three niche dimensions. The repercussions of such variations are highly heterogeneous and differ according to both the type of human disturbance and how the landscape and/or availability of resources are affected. We propose a theoretical framework of the three main outcomes for the impacts of human disturbance on intraguild competition and carnivore community structure: (i) human disturbance impedes niche partitioning, increasing intraguild competition and reducing the richness and diversity of the community; (ii) human disturbance unbalances niche partitioning and intraguild competition, affecting community stability; and (iii) human disturbance facilitates niche partitioning, decreasing intraguild competition and enriching the community. We call for better integration of the impact of humans on carnivore communities in future research on interspecific competition.
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Synopsis Many large predators are also facultative scavengers that may compete with and depredate other species at carcasses. Yet, the ecological impacts of facultative scavenging by large predators, or their “scavenging effects,” still receive relatively little attention in comparison to their predation effects. To address this knowledge gap, we comprehensively examine the roles played by, and impacts of, facultative scavengers, with a focus on large canids: the African wild dog (Lycaon pictus), dhole (Cuon alpinus), dingo (Canis dingo), Ethiopian wolf (Canis simensis), gray wolf (Canis lupus), maned wolf (Chrysocyon brachyurus), and red wolf (Canis rufus). Specifically, after defining facultative scavenging as use or usurpation of a carcass that a consumer has not killed, we (1) provide a conceptual overview of the community interactions around carcasses that can be initiated by facultative scavengers, (2) review the extent of scavenging by and the evidence for scavenging effects of large canids, (3) discuss external factors that may diminish or enhance the effects of large canids as scavengers, and (4) identify aspects of this phenomenon that require additional research attention as a guide for future work.
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Competitively dominant carnivore species can limit the population sizes and alter the behavior of inferior competitors. Established mechanisms that enable carnivore coexistence include spatial and temporal avoidance of dominant predator species by subordinates, and dietary niche separation. However, spatial heterogeneity across landscapes could provide inferior competitors with refuges in the form of areas with lower competitor density and/or locations that provide concealment from competitors. Here, we combine temporally overlapping telemetry data from dominant lions (Panthera leo) and subordinate African wild dogs (Lycaon pictus) with high‐resolution remote‐sensing in an integrated step selection analysis to investigate how fine‐scaled landscape heterogeneity might facilitate carnivore coexistence in South Africa’s Hluhluwe‐iMfolozi Park, where both predators occur at exceptionally high densities. We ask whether the primary lion avoidance strategy of wild dogs is spatial avoidance of lions or areas frequented by lions, or if wild dogs selectively use landscape features to avoid detection by lions. Within this framework, we also test whether wild dogs rely on proactive or reactive responses to lion risk. In contrast to previous studies finding strong spatial avoidance of lions by wild dogs, we found that the primary wild dog lion‐avoidance strategy was to select landscape features that aid in lion avoidance. This habitat selection was routinely used by wild dogs, and especially when in areas and during times of high lion encounter risk, suggesting a proactive response to lion risk. Our findings suggest that spatial landscape heterogeneity could represent an alternative mechanism for carnivore coexistence, especially as ever‐shrinking carnivore ranges force inferior competitors into increased contact with dominant species.
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A pack of 19-29 African wild dogs (Lycaon pictus) in the Masai Mara area of Kenya was monitored during July-August 1989 to document their success in capturing various ungulate species. The pack was most successful killing smaller, abundant ungulate prey, and was not less successful when pack size abruptly was reduced; overall hunting success (all species) was 51%. Abundant prey, low competition with other large carnivores, and large size of pack confound conjecture concerning the evolution of pack size.
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The prey preferences of African lions (Panthera leo) in Serengeti National Park, Tanzania, were examined in three ways. First, lion encounter rates with prey types were measured and compared with a random sample of the prey population. Lions encountered more wart hogs (Phacochoerus aethiopicus), Grant's gazelles (Gazella granti), wildebeests (ConnochaeUs taurinus), and zebras (Equus burchelli) than expected. Second, preferred prey types of lions were identified using conditional logit analysis. Lions preferred to hunt small prey groups, groups that were closer than 200 m, and groups that contained wart hogs, wildebeests, or zebras. Third, a risk-minimization optimal foraging model and a rate-maximization model were used to predict lion preferences. The foraging theory models predict that preferences should change with season and with lion group size. Qualitative support was found for most of these predictions.
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A pack of 17-43 African wild dogs was located during January 1988-June 1989 when it ranged over at least 650 km 2. During mid-July to mid-August 1989 the pack ranged over 250 km 2, travelling at least 10 km per day. Dogs killed most often just before or within 2 hr after sunrise and within 1 hr after sunset. After dogs started hunting they generally travelled 1-2 km in c30 minutes before they killed. Thomson's gazelle Gazella thomsoni were killed most often (67% of 60 kills), and their biomass (48% of total) was equal to the combined biomass of the next 2 most common prey, impala Aepyceros melampus (24%) and wildebeest Connochaetes taurinus (25%). The dogs killed an average of at least three animals per day, regardless of size or composition of the pack; mean minimum consumption rate of edible meat was 1.7 kg prey/dog/day or 0.07 kg prey/kg dog/day. In general, per capita food consumption by wild dogs is related to pack size, the presence of young pups and prey availability. Spotted hyaenas Crocuta crocuta were absent from 59% of wild dog hunts and kills and were usually chased and attacked by the dogs when present. -from Authors
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An observed case of inbreeding in a pack ot wild dogs Lycaon pictus in the Kruger National Park, Republic of South Africa, provides evidence for the phenomenon of dominance reversal in this species. This is believed to be the first recorded instance of inbreeding in Lycaon. Emigration of subordinate females from established packs of wild dogs has been documented in the Serengeti National Park and Ngorongoro Conservation Area in northern Tanzania, as well as in the Kruger National Park. However, the newly subordinate (ex-dominant) female in the pack in which inbreeding has occurred has not emigrated in the 16 months since the change in her status. A possible explanation for this behaviour is given. As a result of this reversal, the pack contains at least two females capable of breeding, the subordinate of which is at least two years older than the dominant. This is considered the first record of such a breeding structure in Lycaon.
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Predator-prey relationships amongst the larger mammals of the Kruger National Park
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The effects of ecological factors (prey, competitors, predators and disease) and intervention (immobilization, radio-collaring, and vaccination) on population size and demography were investigated in Serengeti wild dogs (Lycaon pictus), an endangered canid, between 1965 and 1991. Variation in ecological factors explained most changes in demography, but did not explain a decline in adult longevity. A significant reduction in pack life and individual longevity was coincident with the introduction of routine intervention and consistent with pathogen-induced mortality. Survival varied significantly between categories of intervention, and between individuals likely to have been exposed to different degrees of social stress before intervention. The loss of all study packs in 1991 contrasted with the persistence of breeding packs outside the study area. The cause of the demise of most study packs is unknown. Monte Carlo simulations demonstrated that population extinction was unlikely to be the consequence of chance events alone. One explanation compatible with the evidence is an outbreak of viral disease induced by stress, possibly caused by intervention.
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Rabies was confirmed as the cause of death of one African wild dog (Lycaon pictus) in the Serengeti region, Tanzania. One adult African wild dog in the same pack showed central nervous signs consistent with rabies infection. Inactivated rabies vaccine was administered intramuscularly to African wild dogs in two packs, by dart or by hand following anesthesia. These individuals comprised all known adults in the Serengeti National Park. In a limited study of seroprevalence of rabies antibody carried out at the time of vaccination, 3 of 12 African wild dogs sampled in the Serengeti had rabies serum neutralizing antibody titers before vaccination. Paired serum samples from two individuals sampled after vaccination showed increased antibody titers.
Article
Range use by wild dogs in Hluhluwe-Umfolozi Park was studied between April 1993 and October 1994. Data were collected using radio telemetry assisted by direct observation, triangulation of telemetry bearings and tourist-ranger sightings. Data sets were analysed separately with the program Home Range; and minimum convex polygons were drawn for the pack. Only two outliers were identified in the targe data set; their removal effectively reduced the extent of the unused peripheral areas within the minimum convex polygon, and the area of the home range from 242.35 km(2) to 218.37 km(2). No outliers were identified using telemetry or tourist-ranger data sets. Minimum convex polygon plots of fix locations, and isometric contour plots created from the harmonic mean utilisation distribution, showed a reasonably symmetrical and extensive use of a relatively compact range. There were few if any exploratory excursions outside the home range during the study period.
Chapter
Five methods for studying food habits of large African carnivores are evaluated. Fecal analysis is useful for a basic description of the diet, provided that an adequate sample of scats can be obtained. However, it is impossible to quantify the amount eaten and to determine the proportions of killed versus scavenged food. Tracking spoor in restricted habitats is useful for most species, except the brown hyena (Hyaena brunnea). Opportunistic, and for most species, radio-location observations are biased towards large prey animals, because small animals are eaten quickly, leaving no trace. However, the data can be used to study sex and age selection of adult prey. Direct observations provide accurate measurements of consumption rates, killing frequency, and prey selection, provided they can be carried out without disturbing predator or prey. Mixing data from incompatible techniques must be avoided.
Article
The role of Panthera leo predation in the dynamics of blue wildebeest Connochaetes taurinus and zebra Equus burchelli populations was investigated through simulation models. Data used in the models were from observations in SE Kruger National Park. Model 1 ascertained the number of killing lions (adult females) that could be supported by each prey population while remaining stable. A single model was constructed for the sedentary wildebeest population. A summer and winter model was constructed for the semi-migratory zebra population. The sensitivity of the parameters in the model was tested by changing their value by 10%. In model 2, the kill age structure for each species was changed to determine the number of killing lions the altered prey selection parameters could support. There was no difference in the vulnerability of either species to predation. Zebra foals (<1 yr) were killed more frequently than expected. No selection for sex or by season could be found for either species. Model 1 predicted that the wildebeest population stabilizes with 7.7 killing lions, close to the number in the study area. The winter zebra populations stabilizes with 6.8 killing lions and the summer zebra population with 19.4. Manipulation of kill rate followed by adult fecundity rate had the greatest effect on population size of both species. In model 2, wildebeest predation was made selective towards calves and zebra predation was made non-selective for sex and age. With these parameters the wildebeest population stabilizes with 10.7 killing lions and the zebra population with 5.4 in winter and 15.1 in summer. The models suggest that lion predation affected wildebeest more severely than zebra during the study. This was through the way in which lions selected their prey, and because of the sedentary behaviour of the wildebeest, as opposed to the semi-migratory behaviour of the zebra. -from Authors
Article
African wild dog (Lycaon pictus) predation was observed in Ngorongoro Crater, Tanzania, between September, 1964, and July, 1965, when packs were in residence. The original pack of 21 dogs remained only 4 months, but 7 and then 6 members of the group reappeared in the Crater at irregular intervals. The ratio of males:females was disproportionately high, and the single bitch in the small pack had a litter of 9 in which there was only one female. The pack functions primarily as a hunting unit, cooperating closely in killing and mutual defense, subordinating individual to group activity, with strong discipline during the chase and unusually amicable relations between members. A regular leader selected and ran down the prey, but there was no other sign of a rank hierarchy. Fights are very rare. A Greeting ceremony based on infantile begging functions to promote pack harmony, and appeasement behavior substitutes for aggression when dogs are competing over meat. Wild dogs hunt primarily by sight and by daylight. The pack often approaches herds of prey within several hundred yards, but the particular quarry is selected only after the chase begins. They do not run in relays as commonly supposed. The leader can overtake the fleetest game usually within 2 miles. While the others lag behind, one or two dogs maintain intervals of 100 yards or more behind the leader, in positions to intercept the quarry if it circles or begins to dodge. As soon as small prey is caught, the pack pulls it apart; large game is worried from the rear until it falls from exhaustion and shock. Of 50 kills observed, Thomson's gazelles (Gazella thomsonii) made up 54 percent, newborn and juvenile wildebeest (Connochaetes taurinus) 36 percent, Grant's gazelles (Gazella granti) 8 percent, and kongoni (Alcelaphus buselaphus cokei) 2 percent. The dogs hunted regularly in early morning and late afternoon, with a success rate per chase of over 85 percent and a mean time of only 25 minutes between starting an activity cycle to capturing prey. Both large and small packs generally killed in each hunting cycle, so large packs make more efficient use of their prey resource. Reactions of prey species depend on the behavior of the wild dogs, and disturbance to game was far less than has been represented. Adult wildebeest and zebra (Equus burchelli) showed little fear of the dogs. Territorial male Thomson's gazelles, which made up 67 percent of the kills of this species, and females with concealed fawns, were most vulnerable. The spotted hyena (Crocuta crocuta) is a serious competitor capable of driving small packs from their kills. A minimum of 4-6 dogs is needed to function effectively as a pack. It is concluded that the wild dog is not the most wantonly destructive and disruptive African predator, that it is an interesting, valuable species now possibly endangered, and should be strictly protected, particularly where the small and medium-sized antelopes have increased at an alarming rate.
Book
This is an account of the life and habits of two species of Hyaena, the brown and the spotted, living in South Africa. It contains a considerable body of detailed knowledge, including painstaking nightwork, and it provides help in designing management strategies for species in need of protection. --- Part 1 Feeding ecology: food availability; brown hyaena diet; spotted hyaena diet; diets of the other large carnivores and ecological separation of the predators; the impact of predation on the prey populations; relations between hyaenas and other carnivorous animals. Part 2 Comparative foraging and feeding behaviour: activity patterns and resting sites; foraging group sizes; the use of senses during foraging; foraging for vegetable matter, birds' eggs and insects; brown hyaena hunting behaviour; spooted hyaena hunting behaviour; feeding behaviour. Part 3 Social structure and spatial organization: brown hyaena clans; spotted hyaena clans; nomadic males; land tenure system; factors affecting the sizes of social groups and territories. Part 4 Communication patterns and social interactions: visual and tactile communications and social interactions; vocalizations; scent marking. Part 5 The comparative denning behaviour and development of cubs: dens; development of cubs; sub-adults; functional considerations of denning behaviour in the Hyaenidae. Part 6 The individual in hyaena society: degrees of relatedness between clan members; brown hyaena society; spotted hyaena society; evolutionary trands in the social systems of the two species. Part 7 Relations between, and management considerations for, brown hyaenas and spotted hyaenas. Appendices: 1 - common and scientific names of species mentioned in the text; 2 - estimated numbers of some ungulates in the spotted hyaena study area; 3 - ageing criteria of ungulates based on eruption of teeth in bottom jaws and tooth wear; 4 - methods used to measure territory sizes; 5 - degrees of relatedness between clan members.
Article
The success of a pack of African wild dogs, Lycaon pictus, hunting Thomson's gazelles, Gazella thomsoni, and blue wildebeest, Connochaetes taurinus, in Serengeti National Park, Tanzania, was influenced by the age of the prey and the number of dogs hunting together, but not by the amount of cover available, the size of prey groups, or the distance at which prey groups fled. The study suggested two ways in which wild dogs may benefit from communal hunting. First, it increased the range of prey species available to the pack. Although single dogs regularly killed both immature and adult Thomson's gazelles, they were not observed to kill wildebeest calves, and groups of two did not hunt adult wildebeest successfully. Larger groups were more successful than smaller ones. Second, hunting in groups reduced interspecific competition from spotted hyaenas, Crocuta crocuta , through improved defence of carcasses.
Article
African wild dogs (Lycaon pictus) are large, social canids formerly found throughout sub-Saharan Africa. Wild dogs are now endangered; only six nations hold populations larger than 100 individuals. Considerable evidence suggests that disease plays a central role in the regulation of some wild dog populations. In particular, it has been suggested that epizootics of rabies, canine distemper and anthrax can have strong local effects on wild dog numbers. Resolution of the regulatory importance of these diseases has been hampered by lack of data from wild populations. Here we report on an outbreak of anthrax among wild dogs in the Selous Game Reserve in southern Tanzania, describing clinical signs and diagnosis, measuring mortality, and testing for effects on hunting success and movements. Only one of five packs under study was affected. Immediate mortality was mild, with none of 18 adults (0%) and four of 24 pups (17%) dying. Mortality was significantly higher among puppies (
Article
Lions in the Ngorongoro Crater, Tanzania, form a small and naturally isolated population. In 1962, the Crater lions suffered an epizootic that reduced the population to nine females and one male. An additional seven males apparently immigrated into the Crater in 1964–1965, but there has been no further immigration into the Crater in the past 25 years. By 1975, the population had recovered to its current level of 75-125 animals. All members of the current Crater population are descended from only 15 founders, and over the years there has been considerable variance in the reproductive success of both sexes. The Crater was probably colonized by lions from the nearby Serengeti ecosystem and the contemporary Crater lion population shows a significant lack of genetic diversity compared to the much larger Serengeti population. The detailed reproductive history of the Crater population was incorporated into a series of stochastic computer simulations that generated distributions of expected allele frequencies under different sets of initial conditions. The simulations suggest that the Crater population may have passed through previous bottlenecks before 1962 but that the level of heterozygosity in the breeding population has been declining since the mid-1970s, regardless of the population's genetic composition in the 1960s. High levels of inbreeding are correlated with increased levels of sperm abnormality in lions and there is evidence that the reproductive performance of the Crater lions has decreased as a result of decreasing heterozygosity.
Article
A brief history of past distribution, attitudes and legislation pertaining to Lycaon pictus is given. The species is now restricted to the larger National Parks and Safari Areas in the northwest, northeast and southeast of Zimbabwe. The present total population is approximately 300–350 animals, and is thought to be stable in the larger protected areas. Outside these areas Lycaon continues to be destroyed through the absence of adequate legal protection and public education. Sex ratios, recruitment levels and predation records are summarised.
Article
The social organization and space use of spotted hyaenas, Crocuta crocuta Erxleben, in the Serengeti, Tanzania is described. In contrast to Kruuk (1972, The Spotted Hyena. Chicago: University of Chicago Press), spotted hyaenas in the Serengeti live in large stable groups (clans); median clan size for seven clans was 47 adults and subadults. Clans defended permanent territories that contained the communal den. The size of one well-known territory was 55·5 km2. Territories contained low densities of resident herbivores (mean 3·3 animals/km2) throughout the year, but experienced very high densities (mean 219 animals/km2) of migratory herds, principally wildebeest, Connochaetes taurinus , zebra, Equus burchelli, and Thomson's gazelle, Gazella thomsoni, for only 26% of the year. The most important prey killed inside territories were migratory species. When the migratory herds were away from a clan's territory, clan members regularly left the territory to forage on nearby migratory herds ('commuting trips'). Clan sizes were maintained above the carrying capacity of the territory, estimated from populations of resident herbivores, by year-round exploitation of migratory herbivores. This suggests that, in contrast to many other carnivores, group sizes of Serengeti hyaenas are not limited by resources on the territory and feeding ranges are decoupled from territoriality.
Article
A study of spotted hyenas in the Serengeti revealed that Ss regularly left their clan's territory to feed on the nearest migratory herds (commuting trips). Commuting locations matched the movements of the migratory herds throughout the year. Commuters appeared to minimize contact with resident clans and use areas where they were assured of locating migratory herds. The proportion of clan members commuting declined as prey abundance in the clan's territory increased. Territories were visited by nonresidents (commuters) throughout the year, but the number of foraging commuters increased substantially when large migratory herds entered a territory. During encounters between residents and intruders, residents adjusted their behavior according to the context of the encounter: Residents ignored commuters in transit, responded aggressively to commuters at kills, and engaged in prolonged clashes with neighboring clans. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Article
This paper presents a synopsis of the current status and distribution of the African wild dog Lycaon pictus, outlines reasons for its decline and discusses recommendations to halt or reverse this decline. A recent review of the status of the species provides evidence that it has disappeared or is in decline throughout its range (sub-Saharan Africa). Relict populations with little or no chance of long-term survival are found in several countries including Algeria and Senegal. Countries believed to contain potentially viable populations are, from north to south, Kenya, Tanzania, Zambia, Zimbabwe, Botswana, and South Africa (only the Kruger National Park).
Article
The abundance and spatial organization of spotted hyaenas (Crocuta crocuta) were studied in dense forest of Aberdare National Park, Kenya. Hyaenas were attracted to baits, using amplified tape recordings of hyaena calls. Using sightings of known hyaenas at bait sites and elsewhere population size was estimated with the Lincoln Index as 1·34 hyaena per km2, organized into two territorial clans. Mean clan size was 47. Mean group size of hyaenas moving together was 2·55. Home ranges were exclusive and averaged 32 km2. On a étudié l'abondance et l'organisation spatiale de l'hyène tachetée (Crocuta crocuta) dans la forêt épaisse du Pare National d'Aberdare, Kenya. Les hyènes ont été attiréà des amorces avec des enregistrements amplifiés des appels d'hyène. En utilisant des vues d'hyènes connues à des sites d'amorces et ailleurs, on a estimé la taille de la population avec l'Index Lincoln à 1,34 hyène par km2, organisée en deux clans territoriaux. La taille moyenne de clan était 47. La taille moyenne de groupe d'hyènes qui se déplacent ensemble était 2,55. Les aires de répartition territoriaux étaient exclusifs et avaient un moyen de 32 km2.
Article
During a 13 month survey over 600 lions were lured to capture sites and of these 488 were captured and 409 marked in 158 effort nights (two teams worked for 79 nights). Lions were captured in 96 effort nights out of the 158. Groups of up to 16 were captured per effort night with 80% of all observed lions captured. Seasonal capture rates indicated that there was an inverse relationship between rainfall and capture success, the greatest success being recorded during the dry season. Lions were lured to a game carcass with tape recordings of lions and spotted hyaena calls, and scent trails. All lions were darted at night from the back of a parked vehicle. Record ings were audible to 7 km, the effective luring range with regard to lions being about 4 km. Lions and hyaenas also responded to the sounds in the absence of a carcass or scent trails and approached the sound at a brisk walk. Playing roars often caused lions to move away. Recordings used in conjunction with a carcass and scent trails reduced the time lions took to arrive by a factor of 2.7 when compared to using only a carcass and scent trails. Eighty-three per cent of the darted lions remained within 10 m of the carcass. Both sexes and all age classes except cubs under about 1 month were captured by the technique. The mortality rate was 0.82%.