Article

Effective implementation of age restrictions increases selectivity of sport hunting of the African lion

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Abstract

1. Sport hunting of wildlife can play a role in conservation but can also drive population declines if not managed sustainably. Previous simulation modelling found that large felid species could theoretically be hunted sustainably by restricting harvests to older individuals that have likely reproduced. Several African countries currently use age-based hunting for lions although the outcomes have yet to be evaluated in a wild population. 2. Here we provide the first empirical evidence that a system of incentives sufficiently encouraged age-based hunting and reduced offtake of a wild felid, thereby reducing the potential risk of unsustainable hunting on a threatened species. We examined long-term hunting data and the lion population trend in Niassa National Reserve, Mozambique. 3. To incentivise hunter compliance, a 'points' system was developed which rewards operators that harvest lions older than the 6-year minimum trophy age recommended for sustainable hunting and penalises operators that hunt 'underage' lions (<4 years). A key component of this system is the ecological application of key physical traits that predictably change with age in order to estimate (by hunters) and validate (by authorities) trophy individuals' ages pre-and post-mortem, respectively. Analysis of 138 lion hunts and 87 lion trophies from 2003-2015 Accepted Article This article is protected by copyright. All rights reserved. revealed that after enforcement of age restrictions in 2006, hunters shifted harvests to suitably aged lions (>6 years), from 25% of offtakes in 2004 to 100% by 2014. 4. Simultaneously, the number of lions and percentage of quota harvested decreased, resulting in lower lion offtakes. Following an initial decrease after enforcement of the aging system, the percentage of hunts harvesting lions stabilised, demonstrating that hunters successfully located and aged older lions. 5. Synthesis and applications. Evidence suggests that age restrictions combined with an incentive-based points system regulated sport hunting and reduced pressure on the lion population. We attribute the successful implementation of this management system to: 1) committed, consistent enforcement by management authorities, 2) genuine involvement of all stakeholders from the start, 3) annual auditing by an independent third party, 4) the reliable, transparent, straightforward aging process, and 5) the simple, pragmatic points system for incentivising hunter compliance. Our study demonstrates that the use of age restrictions can increase the selectivity of sport hunting and lower trophy offtakes to reduce the possibility of unsustainable sport hunting negatively impacting species populations in the absence of reliable estimates of population size. It must be noted, however, that there was no measurable change in the lion numbers over the past decade that could be attributed to the implementation of this policy alone.

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... Incentive-based quotas have been implemented inside reserves wherein the harvest of a suitably-aged male results in a quota increase for the following year, sometimes quite significantly [46]. However, reactive quotas still carry the risk the population can decline at a faster rate than the harvest can be adjusted, particularly when hunters increase their effort to confront scarcity [46]. ...
... Incentive-based quotas have been implemented inside reserves wherein the harvest of a suitably-aged male results in a quota increase for the following year, sometimes quite significantly [46]. However, reactive quotas still carry the risk the population can decline at a faster rate than the harvest can be adjusted, particularly when hunters increase their effort to confront scarcity [46]. Secondly, rewarding concessions with higher quotas after harvesting older male could reinforce vacuum effects in lion populations straddling strong gradients of protection. ...
... Around the world, many conservation and natural resource agencies advocate using adaptive management when deciding how to conserve wildlife and ecosystems in the face of uncertainty. A foundational principle of adaptive management is ongoing monitoring of systems as regulations change to generate valuable insight into system functioning that can feedback into future policy formation [46]. Strong evidence that trophy hunting was driving population declines and skew in lion demography resulted from intensive monitoring of the South Luangwa lion population before and after the hunting moratorium. ...
Article
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Factors that limit African lion populations are manifold and well-recognized, but their relative demographic effects remain poorly understood, particularly trophy hunting near protected areas. We identified and monitored 386 individual lions within and around South Luangwa National Park, Zambia, for five years (2008–2012) with trophy hunting and for three additional years (2013–2015) during a hunting moratorium. We used these data with mark-resight models to estimate the effects of hunting on lion survival, recruitment, and abundance. The best survival models, accounting for imperfect detection, revealed strong positive effects of the moratorium, with survival increasing by 17.1 and 14.0 percentage points in subadult and adult males, respectively. Smaller effects on adult female survival and positive effects on cub survival were also detected. The sex-ratio of cubs shifted from unbiased during trophy-hunting to female-biased during the moratorium. Closed mark-recapture models revealed a large increase in lion abundance during the hunting moratorium, from 116 lions in 2012 immediately preceding the moratorium to 209 lions in the last year of the moratorium. More cubs were produced each year of the moratorium than in any year with trophy hunting. Lion demographics shifted from a male-depleted population consisting mostly of adult (≥4 years) females to a younger population with more (>29%) adult males. These data show that the three-year moratorium was effective at growing the Luangwa lion population and increasing the number of adult males. The results suggest that moratoria may be an effective tool for improving the sustainability of lion trophy hunting, particularly where systematic monitoring, conservative quotas, and age-based harvesting are difficult to enforce.
... Nonetheless, the African safari hunting industry has accepted the research findings and is increasingly implementing age-based regulations for trophy hunting of lions (e.g. Begg, Miller, & Begg, 2018). The result has been a marked reduction in the number of young lions taken as trophies. ...
... An allocation of points to each quota, depending on the age of trophies taken, is then applied to the results to determine whether quotas can be increased, decreased, or remain unchanged (e.g. Begg et al., 2018). The approach adopted thus far relies on professional hunters adjudicating the physical characteristics of live animals and then a later, separate subjective assessment of skull morphology by one or more independent researchers. ...
Article
Hunting lions while their populations are declining in much of Africa is a highly controversial issue. However, hunting for lions and other charismatic large mammals in Africa has contributed to maintaining large areas of wild land for lions and wildlife conservation. To minimise the impacts of hunting lions in some 150,000 km² of Game Management Areas (total ∼190,000 km²) in Zambia an age-based quota setting system has been adopted. The approach involves reducing the number of lions taken to one per hunting block and limiting trophy hunting to past prime male lions. The age-based assessment criteria and the results from assessing the trophies taken in 2017 and 2018 are presented. Of the 18 trophies taken in 2017, 11% were judged to be under age, 17% were marginal and the remaining 72% were acceptable trophies of animals aged 6 years or older, with 28% being ≥7 years or older. The results for 2018 showed a higher proportion (42%) of older lions (≥7 years) being taken. Legal instruments to give force to the guidelines on trophies that can legally be hunted are being introduced to ensure the sustainable offtake of past prime male lions with minimal disruption of pride coalitions. These developments will contribute to improved management of lion hunting in Zambia and to meeting the non-detriment finding and conservation enhancement requirements of European and American regulations governing the importation of lion trophies.
... For example, in a study of communal conservancies in Namibia, a simulated ban on trophy hunting reduced the number of conservancies that could cover their operating costs (Naidoo et al., 2016). Others have suggested that well-regulated hunting frameworks and effective governance could minimize trophy hunting's negative impacts on wildlife populations and bring benefits to local communities (Begg et al., 2018;Lindsey, Frank, et al., 2007). ...
Article
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1. Ethical concerns are at the heart of the ongoing debate on trophy hunting; however, so far, most studies have addressed the issue from a single ethical perspective. These studies, approaching the subject from different ethical perspectives, have reached different conclusions. For instance, those who support trophy hunting as a conservation strategy usually adopt a utilitarian perspective, while those who adopt a deontological perspective usually oppose it. 2. The analysis presented in this paper challenges the ethical justification of trophy hunting based on a utilitarian perspective, and it also suggests that trophy hunting is problematic from the perspectives of both deontology and virtue theory. 3. This paper supports a version of Bryan Norton's ‘convergence hypothesis’ (Norton, 1991). Although holism and anthropocentrism in environmental ethics are usually presented as fundamentally opposed views, Norton argued that their conclusions for policy converge, at least when a sufficiently broad and long-range view of human interests are considered. 4. Analogously, this paper proposes that, regarding trophy hunting, the implications of three major traditional perspectives in ethics (i.e. utilitarianism, deontology and virtue theory) may converge in opposition to the practice of trophy hunting. 5. The final section of this paper recommends some ways authorities and policymakers can address these ethical concerns and presents a view of the future.
... Africa is home to the most diverse sympatric large carnivore assemblage on earth, both functionally, and phylogenetically (Dalerum et al. 2008 . This includes the regulation of prey, and plant communities (Ford et al. 2014), photographic and trophy hunting safaris (Mossaz et al. 2015, Begg et al. 2018, and traditional ceremonies across many human cultures . However, populations of these species have suffered significant range contractions across their African range (mean range loss = 68.16%, ...
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.
... prides in total responded(Begg, Miller, & Begg, 2018).Belant et al. (2016) found that lions habituate to call-up sounds very quickly and that temporal and spatial variation of broadcasted sound did not reduce this habituation(Belant et al., 2017), which would imply that areas used for calibration cannot subsequently be surveyed. We did not evaluate the call-up method here. ...
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Apex carnivores are wide-ranging, low-density, hard to detect, and declining throughout most of their range, making population monitoring both critical and challenging. Rapid and inexpensive index calibration survey (ICS) methods have been developed to monitor large African carnivores. ICS methods assume constant detection probability and a predictable relationship between the index and the actual population of interest. The precision and utility of the resulting estimates from ICS methods have been questioned. We assessed the performance of one ICS method for large carnivores-track counts-with data from two long-term studies of African lion populations. We conducted Monte Carlo simulation of intersections between transects (road segments) and lion movement paths (from GPS collar data) at varying survey intensities. Then, using the track count method we estimated population size and its confidence limits. We found that estimates either overstate precision or are too imprecise to be meaningful. Overstated precision stemmed from discarding the variance from population estimates when developing the method and from treating the conversion from tracks counts to population density as a back-transformation, rather than applying the equation for the variance of a linear function. To effectively assess the status of species, the IUCN has set guidelines, and these should be integrated in survey designs. We propose reporting the half relative confidence interval width (HRCIW) as an easily calculable and interpretable measure of precision. We show that track counts do not adhere to IUCN criteria, and we argue that ICS methods for wide-ranging low-density species are unlikely to meet those criteria. Established, intensive methods lead to precise estimates, but some new approaches, like short, intensive, (spatial) capture-mark-recapture (CMR/SECR) studies, aided by camera trapping and/or genetic identification of individuals, hold promise. A handbook of best practices in monitoring populations of apex carnivores is strongly recommended.
... Trophy hunting has been found to trigger phenotypic changes in ungulate populations, such as reductions in body weight and size, as well as the dimension and symmetry of horns (Coltman et al., 2003;Douhard et al., 2016;Garel et al., 2007;Pérez et al., 2011;Pigeon et al., 2016). To avoid evolutionary consequences in managed populations (Allendorf, England, Luikart, Ritchie, & Ryman, 2008), harvests should not impose a strong selection (Begg, Miller, & Begg, 2017;Festa-Bianchet, 2016). Yet, it is still debatable (Ripple, Newsome, & Kerley, 2016) whether a properly managed trophy harvest can be used as a conservation tool for maintaining biodiversity (Di Minin, Leader-Williams, & Bradshaw, 2016). ...
Article
1.Selective hunting can affect demographic characteristics and phenotypic traits of the targeted species. Hunting systems often involve harvesting quotas based on sex, age and/or size categories to avoid selective pressure. However, it is difficult to assess if such regulations deter hunters from targeting larger ‘trophy’ animals with longer horns that may have evolutionary consequences. 2.Here, we compile 44′088 annually resolved and absolutely dated measurements of Alpine ibex (Capra ibex) horn growth increments from 8′355 males, harvested between 1978 and 2013, in the eastern Swiss Canton of Grisons. We aim to determine if male ibex with longer horns were preferentially targeted, causing animals with early rapid horn growth to have shorter lives, and whether such hunting selection translated into long‐term trends in horn size over the past four decades. 3.Results show that medium‐ to longer‐horned adult males had a higher probability of being harvested than shorter‐horned individuals of the same age, and that regulations do affect the hunters’ behaviour. Nevertheless, phenotypic traits like horn length, as well as body size and weight, remained stable over the study period. 4.Though selective trophy hunting still occurs, it did not cause a measurable evolutionary response in Grisons’ Alpine ibex populations; managed and surveyed since 1978. Nevertheless, further research is needed to understand if phenotypic trait development is co‐influenced by other, potentially compensatory factors that may possibly mask the effects of selective, long‐term hunting pressure. This article is protected by copyright. All rights reserved.
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Trophy hunting plays a significant role in wildlife conservation in some contexts in various parts of the world. Yet excessive hunting is contributing to species declines, especially for large carnivores. Simulation models suggest that sustainable hunting of African lions may be achieved by restricting offtakes to males old enough to have reared a cohort of offspring.We tested and expanded criteria for an age-based approach for sustainably regulating lion hunting. Using photos of 228 known-age males from ten sites across Africa, we measured change in ten phenotypic traits with age and found four age classes with distinct characteristics: 1–2.9 years, 3–4.9 years, 5–6.9 years, and ≥7 years.Wetested the aging accuracy of professional hunters and inexperienced observers before and after training on aging. Before training, hunters accurately aged more lion photos (63%) than inexperienced observers (48%); after training, both groups improved (67–69%). Hunters overestimated 22% of lions <5 years as 5–6.9 years (unsustainable) but only 4% of lions <5 years as ≥7 years (sustainable). Due to the lower aging error for males ≥7 years, we recommend 7 years as a practical minimum age for hunting male lions. Results indicate that age-based hunting is feasible for sustainably managing threatened and economically significant species such as the lion, but must be guided by rigorous training, strict monitoring of compliance and error, and conservative quotas. Our study furthermore demonstrates methods for identifying traits to age individuals, information that is critical for estimating demographic parameters underlying management and conservation of age-structured species.
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We apply an age- and stage-structured model incorporating varying harem sizes, paternal care and infanticide to examine the effect of hunting on sustainability of populations. Compared to standard carnivore and herbivore models, these models produce different outcomes for sustainable offtake when either adults, or adult males are harvested. Larger harem size increases sustainable offtake whereas paternal care and infanticide lowers it. Where males are monogamous, populations are vulnerable to male offtake, regardless of paternal care. Surprisingly, an incidental take of 10% of other age–sex-classes has very little effect on these findings. Indiscriminate (subsistence) hunting of all age–sex classes has a dramatic effect on certain populations. Applying these behavior–sensitive models to tourist hunting in the Selous Game Reserve, Tanzania, we find that across the Reserve hunting quotas were generally set at sustainable rates except for leopard (Panthera pardus). In certain hunting blocks within the Reserve, however, quotas for eland (Taurotragus oryx), hartebeest (Alcelaphus buselaphus), lion (Panthera leo), reedbuck (Redunca arundinum), sable antelope (Hippotragus niger), warthog (Phacochoerus aethiopicus) and waterbuck (Kobus ellipsiprymnus) are set at unsustainably high rates. Moreover, particular blocks are consistently awarded high quotas. Behaviorally sensitive models refine predictions for population viability, specify data required to make predictions robust, and demonstrate the necessity of incorporating behavioral ecological knowledge in conservation and management.
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Sport hunting has provided important economic incentives for conserving large predators since the early 1970's, but wildlife managers also face substantial pressure to reduce depredation. Sport hunting is an inherently risky strategy for controlling predators as carnivore populations are difficult to monitor and some species show a propensity for infanticide that is exacerbated by removing adult males. Simulation models predict population declines from even moderate levels of hunting in infanticidal species, and harvest data suggest that African countries and U.S. states with the highest intensity of sport hunting have shown the steepest population declines in African lions and cougars over the past 25 yrs. Similar effects in African leopards may have been masked by mesopredator release owing to declines in sympatric lion populations, whereas there is no evidence of overhunting in non-infanticidal populations of American black bears. Effective conservation of these animals will require new harvest strategies and improved monitoring to counter demands for predator control by livestock producers and local communities.
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In most species, sport hunting of male trophy animals can only reduce overall population size when the rate of removal of males is so high that females can no longer be impregnated. However, where males provide extensive paternal care, the removal of even a few individuals could harm the population as a whole. In species such as lions, excessive trophy hunting could theoretically cause male replacements (and associated infanticide) to become sufficiently common to prevent cubs reaching adulthood. Here we simulate the population consequences of lion trophy hunting using a spatially explicit, individual-based, stochastic model parameterized with 40 years of demographic data from northern Tanzania. Although our simulations confirm that infanticide increases the risk of population extinction, trophy hunting could be sustained simply by hunting males above a minimum age threshold, and this strategy maximizes both the quantity and the quality of the long-term kill. We present a simple non-invasive technique for estimating lion age in populations lacking long-term records, and suggest that quotas would be unnecessary in any male-only trophy species where age determination could be reliably implemented.
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We evaluated the accuracy and precision of tooth wear for aging gray wolves (Canis lupus) from Alaska, Minnesota, and Ontario based on 47 known-age or known-minimum-age skulls. Estimates of age using tooth wear and a commercial cementum annuli-aging service were useful for wolves up to 14 years old. The precision of estimates from cementum annuli was greater than estimates from tooth wear, but tooth wear estimates are more applicable in the field. We tended to overestimate age by 1-2 years and occasionally by 3 or 4 years. The commercial service aged young wolves with cementum annuli to within ±1 year of actual age, but under estimated ages of wolves ≥9 years old by 1-3 years. No differences were detected in tooth wear patterns for wild wolves from Alaska, Minnesota, and Ontario, nor between captive and wild wolves. Tooth wear was not appropriate for aging wolves with an underbite that prevented normal wear or severely broken and missing teeth.
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A system is described for estimating the age of the African lion by studying the eruption sequence of deciduous and permanent teeth of both jaws and the wear of permanent teeth. This system is supplemented by observing criteria such as height of the cemento-enamel line of permanent canines above the alveolar margin, the closure of the apical foramen of the pulp chamber and the discolouration of permanent teeth. Where skulls are available curves and equations describing closure rate with age of the pulp chambers of maxillary and mandibular canines measured at their maximum mesio-distal width, are provided. These measurements can be taken by either sectioning the canines transversely at a certain point or by X-raying the teeth. Sex-specific von Bertalanffy growth curves and equations describing skull growth with age for four skull measurements are also provided while the use of cranial sutures for age determination in the lion is evaluated. Canine root sections were removed, decalcified, sectioned and stained for incremental cementum line counts. The results of this method were in close agreement with the ages of known-age lions and those aged by the previously mentioned methods (r=0.973; P<0–001). A series of photographs and a description is provided whereby lions observed in the field can be classified into age classes. Sexual dimorphism in the permanent canines is described and appropriate measurements given whereby a single permanent canine can be used to decide on the sex of an animal. The use of oxytetracycline and lead acetate for the in vivo“labelling” of teeth in wild lions is examined.
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The paper summarizes seven years of records of the reproductive history of two wild prides of lions (Panthera leo L.) in the Serengeti National Park, Tanzania. These records are analyzed to demonstrate ways in which lion reproduction is influenced by their social group and by changes in that group. Females gave birth at any time of year; they did so sooner if their previous litter died. Females synchronized births with other pride members. Takeover of the pride by new males resulted in a drop in the birth rate. Most cubs died, before two years old. Birth synchrony resulted in better cub survival. The arrival of new males resulted in an increase in cub mortality. Females came into oestrus synchronously with other pride members. Males had a much longer effective reproductive life if they had male companions. The proximate causes of these features of lion reproduction are considered, and the evolution of aspects of the organization of reproduction in lions is discussed.
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Apex predators are often threatened with extinction, and reintroduction is one method conservation managers are using to secure their persistence. Yet the ability to predict what these predators will eat upon reintroduction is lacking. Here we test predictions of the diet of the lion (Panthera leo), derived from dietary electivity index and optimality theory, using independent data collected from reintroduced and resident populations. We solved the Jacobs’ index preference equation for each prey species of the lion using values calculated by Hayward and Kerley (2005) and prey abundance data from 4 reintroduction sites and one resident lion population over several years. We then compared these estimates with actual kill data gathered from each site and time period, using the log-likelihood ratio and linear regression. The model precisely predicted the observed number of kills in 9 of the 13 tests. There was a highly significant linear relationship between the number of lion kills predicted to occur at a site and the number observed for all but one site (x̄r2 = 0.612; β = 1.03). Predicting predator diet will allow conservation managers to stop responding and start planning in advance for reintroductions and environmental variation. Furthermore, ensuring that sufficient food resources are available is likely to increase the success of reintroduction projects. In addition, managers responsible for threatened prey species will be able to predict the vulnerability of these species to predation in the event of predator reintroductions or changes in abundance. These methods are applicable to virtually all large predators that have been sufficiently studied.
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Between 1999 and 2004 we undertook an ecological study of African lions (Panthera leo) in Hwange National Park, western Zimbabwe to measure the impact of sport-hunting beyond the park on the lion population within the park, using radio-telemetry and direct observation. 34 of 62 tagged lions died during the study (of which 24 were shot by sport hunters: 13 adult males, 5 adult females, 6 sub-adult males). Sport hunters in the safari areas surrounding the park killed 72% of tagged adult males from the study area. Over 30% of all males shot were sub-adult (<4 years). Hunting off-take of male lions doubled during 2001–2003 compared to levels in the three preceding years, which caused a decline in numbers of adult males in the population (from an adult sex ratio of 1:3 to 1:6 in favour of adult females). Home ranges made vacant by removal of adult males were filled by immigration of males from the park core. Infanticide was observed when new males entered prides. The proportion of male cubs increased between 1999 and 2004, which may have occurred to compensate for high adult male mortality.
Article
There is a lack of consensus among some conservation NGOs and African governments concerning the acceptability and effectiveness of trophy hunting as a conservation tool. This lack of consensus is due partly to a lack of reliable information on the economic significance and ecological impact of the industry. We provide a review of the scale of the trophy hunting industry, and assess both positive and negative issues relating to hunting and conservation in Africa. Trophy hunting occurs in 23 countries in Africa, with the largest industries occurring in southern Africa and Tanzania, where the industry is expanding. The trophy hunting industry has remained static or is shrinking in Central and West Africa. A minimum of 1,394,000 km2 is used for trophy hunting in sub-Saharan Africa, which exceeds the area encompassed by national parks. Trophy hunting is thus of major importance to conservation in Africa by creating economic incentives for conservation over vast areas, including areas which may be unsuitable for alternative wildlife-based land uses such as photographic ecotourism. However, there are a number of problems associated with the industry which limit conservation benefits. Several of these problems are common to multiple countries, suggesting that if solutions were developed, conservation benefits would accrue over large areas.
Article
Tanzania holds most of the remaining large populations of African lions (Panthera leo) and has extensive areas of leopard habitat (Panthera pardus), and both species are subjected to sizable harvests by sport hunters. As a first step toward establishing sustainable management strategies, we analyzed harvest trends for lions and leopards across Tanzania's 300,000 km(2) of hunting blocks. We summarize lion population trends in protected areas where lion abundance has been directly measured and data on the frequency of lion attacks on humans in high-conflict agricultural areas. We place these findings in context of the rapidly growing human population in rural Tanzania and the concomitant effects of habitat loss, human-wildlife conflict, and cultural practices. Lion harvests declined by 50% across Tanzania between 1996 and 2008, and hunting areas with the highest initial harvests suffered the steepest declines. Although each part of the country is subject to some form of anthropogenic impact from local people, the intensity of trophy hunting was the only significant factor in a statistical analysis of lion harvest trends. Although leopard harvests were more stable, regions outside the Selous Game Reserve with the highest initial leopard harvests again showed the steepest declines. Our quantitative analyses suggest that annual hunting quotas be limited to 0.5 lions and 1.0 leopard/1000 km(2) of hunting area, except hunting blocks in the Selous Game Reserve, where harvests should be limited to 1.0 lion and 3.0 leopards/1000 km(2) .
Article
Tanzania is a premier destination for trophy hunting of African lions (Panthera leo) and is home to the most extensive long-term study of unhunted lions. Thus, it provides a unique opportunity to apply data from a long-term field study to a conservation dilemma: How can a trophy-hunted species whose reproductive success is closely tied to social stability be harvested sustainably? We used an individually based, spatially explicit, stochastic model, parameterized with nearly 40 years of behavioral and demographic data on lions in the Serengeti, to examine the separate effects of trophy selection and environmental disturbance on the viability of a simulated lion population in response to annual harvesting. Female population size was sensitive to the harvesting of young males (≥3 years), whereas hunting represented a relatively trivial threat to population viability when the harvest was restricted to mature males (≥6 years). Overall model performance was robust to environmental disturbance and to errors in age assessment based on nose coloration as an index used to age potential trophies. Introducing an environmental disturbance did not eliminate the capacity to maintain a viable breeding population when harvesting only older males, and initially depleted populations recovered within 15-25 years after the disturbance to levels comparable to hunted populations that did not experience a catastrophic event. These results are consistent with empirical observations of lion resilience to environmental stochasticity.
Hunting Season: Trophy Monitoring in Niassa National Reserve, Mozambique: Lion
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Aerial Survey of Wildlife in the Niassa Reserve and Adjacent Areas
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Craig, G.C. (2009) Aerial Survey of Wildlife in the Niassa Reserve and Adjacent Areas, October 2009.
Aerial Survey of Wildlife in the Niassa Reserve
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Craig, G.C. (2012) Aerial Survey of Wildlife in the Niassa Reserve, October 2011.
Accuracy and precision of estimating age of Accepted Article This article is protected by copyright. All rights reserved. gray wolves by tooth wear
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Gipson, P., Ballard, W., Nowak, R. & Mech, L. (2000) Accuracy and precision of estimating age of Accepted Article This article is protected by copyright. All rights reserved. gray wolves by tooth wear. Journal of Wildlife Management, 64, 752–758.
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A Hunter's Guide to Aging Lions in Eastern and Southern Africa
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Whitman, K.L. & Packer, C. (2007) A Hunter's Guide to Aging Lions in Eastern and Southern Africa. Safari Press, Long Beach, California.
Aerial survey of elephant, other wildlife and human activity in the Niassa National Reserve and adjacent areas
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Endangered and threatened wildlife and plants; listing two lion subspecies
  • U.S. Fish and Wildlife Service