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Some effects of hunting on wild mammalian populations
... A prolonged exposure to a stressful situation can even lead to a downregulation of adrenocorticoid output as a form of physiological protection measure, for example as shown in a rhino translocation study (Linklater et al. 2010). However, most other studies found that declines in food quality (Foley et al. 2001;Viljoen et al. 2008a) and hunting pressures elevated levels of GCs associated with stress in large animals (Bateson and Bradshaw 1997;Sforzi and Lovari 2000). Moreover, heavily hunted populations of other megaherbivores [e.g. ...
... Specifically, using a non-invasive method for quantifying faecal glucocorticoid metabolites (fGCM), we wanted to (1) validate our field methodology and understand the stability of fGCM concentrations for rhino post-defecation, and (2) correlate fGCM concentrations of four rhino populations to both environmental and anthropogenic challenges. We predicted that rhinos in areas with high poaching pressure would have higher fGCM concentrations compared with rhinos in areas with low poaching pressure due to their heightened perception of risk in these areas (Bateson and Bradshaw 1997;Sforzi and Lovari 2000;Vilela et al. 2020). Additionally, we predicted rhinos sampled during the dry season (August-September; when resources are limited) in the smaller protected areas that constrain this wide-ranging species Mason 2003, 2007;Metrione et al. 2007) would have higher fGCM concentrations. ...
... Physiologically, the absence of higher fGCM levels could be a result of a negative feedback loop, where perceived stress over a prolonged period leads to a downregulation of adrenocortical activity (Linklater et al. 2010). However, studies have linked poaching and hunting activities to elevated fGCM concentrations in other species, like elephants (Gobush et al. 2008) and red deer (Cevus elaphus) (Bateson and Bradshaw 1997;Sforzi and Lovari 2000;Vilela et al. 2020). Rhinos' muted response to continued poaching may be due to habituation to continuous anthropogenic disturbance F www.publish.csiro.au/wr ...
Context Due to considerable declines in African wildlife populations, most large African mammals are managed inside protected areas. Protected areas come in various sizes, and have different environmental features, climates and management strategies (i.e. ‘hands-on’ or ‘hands-off’) that can influence an animals’ homeostasis. White rhinos (Ceratotherium simum simum) are found almost exclusively within protected areas where population sizes are driven by natural factors and poaching pressures. Aims Our aim was to understand the effect of natural and anthropogenic factors on the adrenocortical response of white rhinos within three protected areas. Specifically, we wanted to understand how poaching pressure, protected area size (<500 km2), season (wet and dry) and rainfall patterns were responsible for driving adrenocortical activity in white rhino. Methods To understand the relationship between rhino adrenocortical responses and different environmental and anthropogenic stressors, we quantified glucocorticoid metabolites in faecal samples (fGCM) collected from four populations within three protected areas (i.e. two small parks, one big park) during the wet and dry seasons. Key results We found differences in seasonal fGCM concentrations, with a 42% increase during the dry season, and no differences in fGCM concentrations between the high and low poaching areas. Additionally, we found fGCM concentrations in samples from the small parks were respectively 38% and 42% higher than in samples from the large park during both the dry and wet seasons compared. Conclusions Our results suggest that white rhinos may experience physiological stress in smaller parks, especially during the dry season when resources are limited. Implications By mitigating stress associated with reduced access to resources and spatial constraints, managers may better promote the viability of large mammals in small protected areas.
... Hunting implies the presence of humans, and possibly of hunting dogs, on a territory where both target and non-target animal species occur. The increases of noise and perception of predation risk by wildlife result in chronic or acute disturbance of spatio-temporal behaviour (Kilgo et al. 1998;Sforzi and Lovari 2000). For ungulates, the most evident chronic effect is commonly known as the Breserve effect^: human activity (as well as the lack of apex predators) may be responsible for abnormal concentration of deer and wild boar in protected areas, with cascade effects on local vegetation communities (Grignolio et al. 2011; see also Mysterud 2013 for human shielding). ...
... Direct and indirect exploitation by humans is known to alter population dynamics (Jeppesen 1998;Solberg et al. 2002), spatial behaviour (Kilgo et al. 1998;Tolon et al. 2009), group size (Maillard and Fournier 1995;Scillitani et al. 2010) and duration of activity (Sforzi and Lovari 2000;Kamler et al. 2007) of wildlife. Particularly, hunting directly exposes wild species to an enhanced level of predation risk. ...
... The increased predation risk forced wild boar to exhibit an altered spatial behaviour and a displacement of family groups (Scillitani et al. 2010). While the effects on game species and large ungulates have been studied thoroughly (e.g., Sforzi and Lovari 2000;Grignolio et al. 2011;Ohashi et al. 2013;Zaccaroni et al. 2012), little attention has been paid to terrestrial mammals of conservation concern. Despite being an introduced species (Bertolino et al. 2015), in Europe, the crested porcupine is safeguarded by the Berne Convention (Annex II) and the Habitat Directive (Annex IV). ...
Human presence (e.g. hunting, ecotourism and wildlife photography) affects animal behaviour. Hunting pressure increases the perception of predation risk in ungulates and hares and may force them to create clumped groups within protected areas. Acute effects are showed immediately after harassments and may include displacement of home ranges, alteration of activity rhythms and increased hormone secretions. No study has been carried out yet on behavioural alterations induced by hunting on non-target, legally protected species, whereas these studies should be required to design addressed management and conservation plans. The crested porcupine Hystrix cristata represents a suitable model species to study effects of hunting on protected species, as its ranging movements and activity rhythms are seasonally, stereotypical-ly repeated. My results on individually marked porcupines showed that, when hunting with dogs occurred, a displacement of home range arises towards areas providing easily accessible food resources (i.e. fruits, which do not require digging). This behaviour might prevent porcupines to spend a high amount of time digging bulbs and tubers and, thus, it may result in a reduction of activity bouts. Home range displacement has also been observed only when >10 cm of snow are present on the ground. The presence of hunting dogs increases the predation risk perception by potential prey species, which in turn respond by altering their spatio-temporal behaviour. Wildlife managers should therefore evaluate the use of a small number of specialized dogs for hunting in management and conservation plans, particularly in areas characterized by the presence of endangered and protected species.
... Det finns många studier som visar att jakt med människor och hundar kan ha stor påverkan på djur (Stephenson et al., 1996;Sforzi & Lovari, 2000;Reyna-Hurtado & Tanner, 2005;Grignolio et al., 2011). Till exempel kan jakt inverka på vilket sätt och hur mycket tid djur använder olika typer av habitat (Reyna-Hurtado & Tanner, 2005) samt på storleken av dess areal (Stephenson et al., 1996;Grignolio et al., 2011). ...
... Om man fokuserar på storleken på hjortars hemområde har man sett att hjortar ökar arealen på området som en reaktion på jakt (Stephenson et al., 1996;Grignolio et al., 2011). Detta kan förklaras av att hjortar bland annat lämnar det störda området (Sforzi & Lovari, 2000;Sunde et al., 2009), söker skydd i områden där jakt inte är tillåtet (Grignolio et al., 2011) samt undviker områden med hög mänsklig aktivitet (Kilgo et al., 1998). Man har även sett en ökad areal hos hjortar som inte befunnit sig direkt i jaktområdet utan i angränsande områden (Sforzi & Lovari, 2000). ...
... Detta kan förklaras av att hjortar bland annat lämnar det störda området (Sforzi & Lovari, 2000;Sunde et al., 2009), söker skydd i områden där jakt inte är tillåtet (Grignolio et al., 2011) samt undviker områden med hög mänsklig aktivitet (Kilgo et al., 1998). Man har även sett en ökad areal hos hjortar som inte befunnit sig direkt i jaktområdet utan i angränsande områden (Sforzi & Lovari, 2000). Neumann et al. (2009) såg dock i deras studie på älgar (Alces alces) ingen urskiljbar påverkan på älgars rörelse i jaktområdet under jaktaktivitet. ...
... Park hunters frequently reported on the characteristic wariness of axis deer and their weak response to the bait during controlled-shooting sessions. Sex-specific differences in ungulate responses to hunting are fairly common and entail reduced exposure of pregnant or lactating females to hunters and predators (Stankowich 2008;Marchand et al. 2014;Pecorella et al. 2019); transient dispersal to suboptimal, safer habitats (Batcheler 1963), and increasing adoption of strictly nocturnal habits (Sforzi and Lovari 2000;Van Doormaal et al. 2015;Ikeda et al. 2019). Axis deer were characterized as being extremely alert and less responsive during the night in India (Graf and Nichols 1966;Schaller 1967), and suggest), and the sighted deer truly represented the number available for shooters. ...
Overabundant ungulate populations are frequently hard to control in woodlands and protected areas, such as El Palmar National Park, where controlled shooting failed to reduce the relative abundance of axis deer (Axis axis) over a decade. We compared the effectiveness of spotlight hunting to cull axis deer with daytime and nighttime controlled shooting over bait stations. We tested whether harvest composition differed among methods by multiple regression and fitted functional response models to culling and sighting data. The trial included 18 sessions and 49 hunter groups, each supervised by a park ranger, who traveled a randomly allocated, fixed itinerary in a slow-moving vehicle, sighted and shot the deer, and retrieved and measured the carcass. Spotlighting culled 2.8–6.2 times more deer per hunting party-session and a significantly greater fraction of subadult or adult deer than daytime and overnight shooting. Relatively more females were culled by spotlighting (58.5%) than by daytime (43.5%) and overnight (47.3%) sessions. Pregnancy rates were 2.4–3.8 times greater by spotlighting (34.0%) than in overnight (14.1%) or daytime (9.0%) sessions. The deer harvested by spotlighting or overnight shooting were significantly heavier than those culled by daytime sessions. A Type II functional response fitted the data better than other competing models. Inter-method differences in harvest size and composition most likely explain the historical inability of daytime shooting to curb deer numbers despite intensified efforts. Spotlighting conducted by supervised, organized hunters was effective for targeted deer control and removed deer with greater reproductive value than shooting over bait stations.
... For wild boar, CAB and LPP also differed in their number of drive hunts during a given hunting season (91 ± 10 drive hunts per hunting season for CAB and 29 ± 8 drive hunts per hunting season for LPP; Fig. 1) and the number of dogs used during each drive hunt (11 ± 7 per 100 ha of hunting area vs. 6 ± 4 for LPP; Fig. 1), but had similar number of shooters and beaters involved in each drive hunt (37 ± 17 shooters and 17 ± 9 beaters per 100 ha of hunting area for CAB and 38 ± 16 shooters and 17 ± 8 beaters for LPP; Fig. 1). Since hunting with higher numbers of dogs (Sforzi andLovari 2000, Grignolio et al. 2011) or more frequently may induce stronger effects on prey behaviour, we may still expect differences in terms of wild boar's space use during the drive-hunting season between the two study sites. ...
Les effets des changements globaux sur les habitats naturels sont de plus en plus perceptibles, et comprendre comment les animaux y répondent est nécessaire pour une meilleure gestion de leurs populations. C’est en effet à travers leur impact sur l’environnement, et essentiellement sur les habitats, que les activités humaines ont souvent le plus grand effet sur les écosystèmes, à travers le changement climatique, la fragmentation, la destruction de l'habitat, les changements dans l'utilisation des terres ou la surexploitation des ressources. Les ongulés constituent un exemple marquant de progression numérique et spatiale d’une guilde d’espèces dans des écosystèmes impactés par l’Homme. Cet essor démographique est à l’origine d’un nombre croissant d’interactions entre Homme et faune et place la gestion de ces espèces au cœur des préoccupations des politiques publiques. Dans ce contexte, j’ai étudié cinq espèces de grands ongulés sauvages : le chamois, le mouflon, le bouquetin, le chevreuil et le cerf, dans le cadre du projet Mov-It (Ungulates MOVing across heterogeneous landscapes: identifying behavioural processes linking global change to spatially-explicIT demographic performance and management), soutenu par l’Agence Nationale de la Recherche (ANR). Dans un premier temps, je mets en évidence les liens entre variations intraspécifiques de la taille du domaine vital saisonnier des ongulés, le paysage (i.e. les ressources, le risque et l’hétérogénéité) et les traits d’histoire de vie de ces espèces. Je me suis ensuite intéressée plus particulièrement à l’influence des structures linéaires anthropiques et naturelles du paysage sur l'utilisation individuelle de l'espace. Je montre ainsi que les grands herbivores utilisent des structures linéaires du paysage pour délimiter leur domaine vital mensuel, mais que l'importance relative de ces structures linéaires dans la délimitation du domaine vital mensuel diminuait à mesure que leur densité augmentait dans le paysage local. Je mets également en évidence le caractère risqué des structures anthropiques pour les ongulés, en particulier l'effet de l'intensité de l’utilisation humaine de ces structures sur le nombre de traversées par les mouflons. Enfin, l’importance de la prise en compte du paysage du risque et des ressources sur l’organisation sociale est démontré. En effet, la formation de dyades (i.e. paires d’individus) est plus probable dans les milieux ouverts riche en ressources et lorsque le risque, incluant prédation et dérangement, est le plus fort (i.e. le jour). L’ensemble des résultats présentés dans ce travail de thèse a permis d’améliorer notre compréhension des effets de la structure du paysage et de la socialité sur la sélection d’habitat et le mouvement chez différentes espèces d’ongulés.
... These results are in accordance with Hell et al. (2005) with higher frequency of road kills in spring and summer. In autumn, increase in AVC is likely to denote the impact of hunting activities on movement of game species (Sforzi and Lovari 2000). Peak of AVC for roe deer in spring can also be related to natal dispersal of sub adults (Wahlström and Liberg 1995) and confirmed results obtained in others studies (Lagos et al. 2012;Markolt et al. 2012 ...
This paper is the first dealing with animal-vehicle collisions (AVC) with red and roe deer in South Tyrol, Northern Italy. The Autonomous Province of Bolzano (South Tyrol) has been collecting AVC data since 2012 on the entire provincial road network. Each year, AVC data accounted for more than 700 cases per year, with several socioeconomic and ecological implications. The aim of this research is to identify the locations where AVC occur more frequently than expected (hotspots) and better outline subsequent implementation of mitigation measures. For an effective identification of AVC hotspots, we applied a combined methodology of temporal and spatial analysis on AVC data collected on the South Tyrol road network in the years 2012–2014. AVC data enabled the identification of the temporal patterns, which showed different behaviors of the two target species in close proximity of the road network and throughout the 12 months. The KDE+ software applied to the 2012–2014 AVC database allowed for spatial analysis and the identification of hotspots, i.e., the road sections having the highest risk for drivers. The integration of the results, coming from the abovementioned methodologies, contributes to a detailed assessment of roads that would allow the identification of the local contributing factors and a base-line of potential problematic areas that will highlight the need for further investigation to assess whether the risk-rank is accurate and allocate effectively limited resources to a feasible number of identified hotspots and reduce the current degree of AVC in the South Tyrolean road network.
... Hunting activity causes an increase in daily movement and changes in the home range of ungulates (e.g. Sforzi & Lovari 2000, Etter et al. 2002, Morelle et al. 2015. The higher number of collisions with the wild boar in NW Spain in autumn has been explained in terms of the combined effect of hunting and longer nights (it is usually active at night and twilight, thus, the probability of collision is higher when nights are longer) (Lagos et al. 2012). ...
Wildlife–vehicle collisions (WVC) pose a serious socio-economic
and traffic safety issue. We investigated factors affecting the location and number of WVC on the expressway “Tri-City Bypass” in a suburban area in N Poland. We analysed WVC with large-sized (LSM; ungulates; 54% of roadkills) and small-sized mammals (SSM; mainly carnivores; 46% of roadkills) and both groups combined (AM). We identified WVC hotspots and analysed factors affecting their spatial distribution with Poisson regression based on four sets of landscape and road-related features (area, patchiness, presence and other features). The most frequent mammal victims of WVCs were wild boar Sus scrofa (31%), roe deer
Capreolus capreolus (21%) and European badger Meles meles (13%), among LSM, and red fox Vulpes vulpes (27%) among SSM. In general, our results indicated that most WVCs occurred in areas with a higher number of forest patches and a higher total length of forest
edge (AM, LSM), in curvy sections of the road (LSM). The number of WVCs was lower in locations covered by urbanized areas and grassland (LSM), in the sections with fences, exits and overpasses (LSM, AM). The road sections where there is a higher risk of severe collisions (involving large species) are situated in areas where the Tri-City Bypass bisects a highly forested area, which serve as movement corridors for LSM between fragmented forest complexes. We conclude that the number of WVCs can be reduced by
preventing animals from accessing the road and ensuring a safe road crossing. This could be achieved by extending fencing and retrofitting some existing underpasses.
... In addition to their effects on the movements of wildlife populations, limited research on ungulates suggests that being chased by dogs may compromise the animals' health( Bateson and Bradshaw, 1997 ;Sforzi and Lovari, 2000 ).12-Gompper-Chap11.indd 277 12-Gompper-Chap11.indd ...
This chapter focuses on evaluating the effects of hunting with dogs on wildlife populations and the importance of these impacts for conservation and wildlife management. It examines scenarios in which the use of dogs can bias harvests towards one sex or the other, or to a particular age category in the prey population. It also considers the documentation of the effects of hunting with dogs on the habitat use and ranging behavior of wildlife populations.
In the process of avoiding predation, prey are faced with potentially fitness‐compromising trade‐offs that have implications for their survival and reproduction. The nature and strength of these non‐consumptive effects at the population level can be equivalent, or even greater, than consumptive effects.
Many prey species have evolved defence mechanisms that are induced by predation risk. These inducible defences can be morphological or behavioural in nature. Extensive research has detected these defences in predator–prey communities across freshwater, marine and terrestrial ecosystems. Among this vast research however, an influential portion of these systems has not been widely considered.
Humans inhabit a level in trophic systems above apex predators. In that position, humans have been referred to as a hyperkeystone or super predator species as they have shown a capacity to consume animals at rates many times higher than any other non‐human species. However, the extent to which humans induce adaptive defences in animals is not as clear. Systems involving large mammals may be particularly well‐suited for the study of human‐induced defences given that these species have been disproportionately exploited (for food and competition) over evolutionary time by humans.
To begin this process we first had to examine the context in which large mammals could adaptively evolve inducible defences in relation to human lethality. With the plausibility of these conditions satisfied, we then conducted an extensive review to document the inducible defences that have been detected in large mammals. All of the 187 studies reviewed documented the behavioural plasticity of large mammals to human lethality. No morphological adaptive defences were detected.
However, the extent to which the observed behavioural plasticity of large mammals is representative of adaptive inducible defences remains unclear because the fitness trade‐offs (i.e. costs), an integral condition for inducible defences to evolve, were implied rather than quantified among close to 92% of this research. We make recommendations for renewed ingenuity in the development of field experiments that can quantify these costs and discuss the implications of human lethality on the ecology, conservation and management of large mammals.
A free Plain Language Summary can be found within the Supporting Information of this article.
Context Human activities can induce behavioural and stress responses in wild animals. Information is scarce on the effects of culling on anti-predator behaviour and endogenous stress response of wild ungulates. Aims In a Mediterranean area, we evaluated the effects of culling on vigilance, foraging and endogenous stress response of female fallow deer (Dama dama). Methods Effects of culling were evaluated through behavioural observations and hormone analyses of faecal samples. Key results In an area where culling occurred (C), individuals showed significantly greater vigilance rates and foraged closer to wood than in an area with no culling (NC). In C, 24h after culling, faecal cortisol concentrations were greater than those recorded in NC, but they decreased significantly to values comparable to (48h post-shot) and lower than (72h post-shot) those observed in NC. Conclusions Most likely, culling determined behavioural responses in female fallow deer, but did not trigger long-term physiological effects. Implications Increased anti-predator behaviour may complicate the implementation of long-term culling programs.
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