Harvest management quotas for fishers Pekania pennanti in some jurisdictions are estimated from the previous year's harvest, and stem from the hypothesis that age ratios in the harvest are largely influenced by ‘top–down’ trapping pressure. The influence of ‘bottom–up’ food supply on fisher harvest age ratios might be underappreciated, which could result in a misallocation of quotas in management planning. We assessed a variety of data sources to test the influence of bottom–up processes on fisher populations in Ontario, Canada. We found evidence that bottom–up trophic effects influence the harvested fisher age structure in some regions of Ontario. Evidence also suggests that harvest pressure had little top–down influence on age ratios over the course of our study, and that basing management strategies on this assumption may lead to unintentional overharvest in years of low productivity. We suggest several trophic linkages with potential to facilitate fisher management, including connections among berry and seed crops, small mammals and northern saw-whet owls Aegolius acadicus.

Alpine black grouse populations are generally declining, but the underlying demographic drivers are largely unknown. We studied the dynamics of two adjacent black grouse populations over a 20 years period in the Italian Alps that differ in hunting pressure to identify the main demographic process affecting these populations and to study the impact of hunting on males. We collected radio-tracking data and conducted population surveys in spring to count displaying cocks and in late summer to determine the breeding success by means of pointing dogs. These different data sets were jointly analysed using a seasonal integrated population model to estimate population sizes and various demographic rates. The two populations fluctuated in size and the number of males from one population increased after hunting intensity was reduced. The main demographic rates did not differ between the populations. Adult survival was relatively low and productivity was high, so the life history shows the feature of a fast turnover species. In both populations, the variability of survival from hatching to the age of five weeks (chick survival) contributed more to the variation of the population growth rates than the variability of survival in later life-history stages, and the former was positively affected by ambient temperatures in July, favouring chick survival. The adult sex ratio of the population where males hunting occurred was shifted towards females, but it evened over time with the reduction of hunting pressure. The adult sex ratio in the population without hunting and the chick sex ratios in both populations were even, suggesting that hunting acted as a mostly additive source of mortality.

Several ground-nesting bird species living in European farmlands are experiencing a persistent decline. Poorer reproductive success is suspected to be the main demographic driver. We developed a model to quantify to what extent such recent change may impact the viability of their populations. We took the grey partridge Perdix perdix, a typical farmland species, as a well-documented case study, but the model can be adapted to other species. We built a model based on our in-depth demographic knowledge of this species and the large database compiled from our long-term population monitoring programme. We took into account environmental and demographic stochasticity as well as density-dependence processes. We investigated the impact of recent changes in reproductive success on the viability of (unharvested) populations. For this purpose, we considered two periods: 1979–2004 as ‘Past’ and 2005–2014 as ‘Present’ (we used data of subsequent years to test the model’s goodness of fit). During the ‘Past’ period, the simulated population was increasing with a mean stochastic growth rate λ_mean = 1.01 (25% of decreasing trajectories), whereas λ_mean = 0.89 during the ‘Present’ period (74% of decreasing trajectories). We provide detailed results and discuss the possible environmental causes, with a focus on extreme weather events. In a further step, we used our model as a tool to investigate the impact of four hunting bag management strategies on exploited populations. The hunting bag was assumed to be an additive cause of mortality. Hunting leads to a decrease in λ_mean but the amplitude (from minor to substantial) depends upon the strategy and the setting-up of parameters. We deliver our model as a tool to support decision-making for sustainable population management and provide the script (ULM software) as Supplementary information.

Estimates of abundance and occupancy are essential for wildlife management, particularly for species of conservation concern such as eastern spotted skunks Spilogale putorius. Most studies of eastern spotted skunks rely on limited evidence for best monitoring practices, and while many studies use attractants to increase detections, previous studies have not tested attractants against a control of no attractant to determine their effectiveness. We tested two common attractants (sardines and fatty acid tablets) and one uncommon attractant (wild boar carcasses) against a control of no attractant to determine if any attractant increased detections of eastern spotted skunks or changed their temporal activity. Based on our model, sardines and wild boar carcasses improved detections by three and eight times that of the control, respectively. Further, for every 100 trap nights, we detected eastern spotted skunks 10.67 times with wild boar carcasses, 1.02 times with sardines, 0.53 times with fatty acid tablets and 0.44 times with no attractant. Wild boar carcasses also substantially decreased latency to detection, with skunks detected two times faster than at other attractants and almost three times faster than at the control. Eastern spotted skunks were most active in the early morning before sunrise, and their temporal activity did not vary significantly by attractant. This study is the first to use an experimental framework to test attractants for eastern spotted skunks, and our results showed that choice of attractant matters. Large animal carcasses, although rarely used, may be most effective for detecting eastern spotted skunks, while fatty acid tablets were no different than the control, and we recommend against their use in future studies. Monitoring plans should incorporate our results as increasing detections is essential to understanding the abundance, range and demographics of eastern spotted skunks.

Population growth in wild boars and feral pigs Sus scrofa has negative environmental and economic implications worldwide. Accordingly, it is necessary to monitor population trends for appropriate management. Despite the potential for bias, relative abundance indices based on signs of activity have the potential to be practical, low-cost monitoring tools for data collection at a local scale and over large areas. However, few studies have examined the effectiveness of specific signs as measures of relative wild boar abundance in comparison with reliable density estimates. In this study, we examined whether three activity signs (digging marks, rubbing marks and fecal pellet groups) could be used as relative abundance indices for wild boar. In particular, we conducted transect surveys for signs of activity as well as camera trap surveys from September 2017 to January 2018 at six sites in Hyogo Prefecture and eight sites in Chiba Prefecture, Japan. We modeled the relations between the number of activity signs and wild boar densities or abundances estimated from camera trap data in a hierarchical framework. Fecal pellet counts is a well-established method for estimating the abundance of herbivores, including wild boar; however, we found few fecal pellet groups in our study area, and the counts were not related to wild boar densities. Instead, we found that digging marks were strongly associated with estimates of wild boar density. Although fluctuations in the number of digging marks may be affected by factors other than boar density, including environmental conditions and seasonality, our results suggest that digging marks are an effective relative abundance index for evaluations of the spatial patterns of wild boar in Japan.

Habitat heterogeneity and corresponding diversity in potential prey species should increase the diet breadth of generalist predators. Many previous studies describing puma Puma concolor diets in the arid regions of the southwestern United States were focused within largely xeric locations, overlooking the influence of heterogeneity created by riparian forests. Such habitat heterogeneity and corresponding prey diversity could influence prey availability and puma diet composition. We examined seasonal prey composition of pumas occupying areas with different habitat conditions representing riparian areas adjacent to the Rio Grande and xeric Chihuahuan Desert uplands in southern New Mexico. We collected prey composition data from 686 kill sites made by 17 (9 males and 8 females) GPS-collared pumas from 2014 to 2018. Diet composition included 32 different avian, aquatic, small mammal, and ungulate prey species. Prey composition varied, with more ungulate prey consumed by pumas inhabiting the upland desert areas and more aquatic prey consumed in the riparian bosque. Prey composition differed between seasons, with ungulate prey decreasing and aquatic prey increasing during the hot–dry season. Prey composition also varied between puma sex and habitat with females in the desert uplands consuming more small mammals than either males or females in riparian areas. The diverse diets of the pumas inhabiting the heterogeneous landscapes in southern New Mexico provide additional evidence that pumas have broad diets that are strongly influenced by the habitat and prey community that their home range encompasses.

Elucidating the factors affecting the foraging habitat selection of wildlife can further our understanding of the animal–habitat relationships and inform wildlife conservation and management. Canopy and understory vegetation may directly or indirectly affect the foraging habitat selection of carnivores through changes in habitat structure and prey availability, respectively; however, the relative importance of these two effects remains largely unknown. Dwarf bamboo Sasa kurilensis is a predominant understory plant that suppresses regeneration in the forests of northern Japan. The purpose of this study was to disentangle the direct and indirect effects of canopy forest type Larix kaempferi plantation versus natural mixed forest) and dwarf bamboo on foraging habitat selection of a large carnivore, the brown bear Ursus arctos. In the Shiretoko World Heritage, brown bears dig for cicada nymphs during summer. We evaluated the frequency of brown bear foraging on cicadas by investigating traces of digging for cicada nymphs. A structural equation model was used to statistically disentangle the direct and indirect effects of vegetation. Our results demonstrated that canopy and understory vegetation directly and indirectly affected foraging habitat selection of brown bears. Dwarf bamboo negatively affected cicada nymph density, which positively affected brown bear digging. This suggests that dwarf bamboo also had indirect negative effects on brown bears. Forest type had significant direct and indirect effects via change in cicada nymph density on foraging behavior in brown bears. Forestry managers in northern Japan, including the study site, try to remove dwarf bamboo for assisting natural regeneration. Removal of dwarf bamboo by scarification might not only promote natural regeneration, but also provide a beneficial foraging habitat for bears.

This study was undertaken in spring, 2019 to assess the applicability of the double-observer survey method for estimating blue sheep Pseudois nayaur abundance in Nar-Phu valley of Manang District located in Annapurna Conservation Area of northern Nepal. Since counting large mammals in rugged mountain habitat poses a special challenge, we tested the efficacy of the double observer method for generating robust population estimates for this important protected area. The overall detection probability for observers (O1 and O2) was 0.94 and 0.91 for a total of 106 groups comprised of 2059 individual blue sheep. We estimated the area's blue sheep population at 2070 (SE ± 168.77; 95% CI 2059–2405) for the 246.2 km² of sampled habitat. We determined blue sheep to be widely distributed within the study area with a mean density of 8.4 individuals per km² based on a total study area of 246.2 km². We discuss demographic population structure and identify limitations when applying the double observer approach, along with recommending viewshed mapping for ensuring more robust density estimates of mountain-dwelling ungulates like blue sheep or ibex that inhabit extremely heterogeneous terrain which strongly influences sighting distances and overall animal detection rates.

Conflict with humans and habitat fragmentation are major threats to large carnivores in Africa, and transboundary protected areas may ease some of the space requirements for individual countries. The W-Arly-Pendjari complex (WAP) in West Africa sits across Benin, Burkina Faso and Niger and is the last regional stronghold for many species, including the regionally critically endangered lion Panthera leo. However, variation in monitoring efforts, limited resources and imperfect coordination confound their conservation.

We demonstrate a cost-effective and scalable design to effectively identify the landscape-level factors that limit the distribution and abundance of large carnivores and their preferred prey. We used an occupancy framework for a combination of spoor and line transect data. We found a high degree of variation in prey density, strongly related to evapotranspiration. Lion occupancy increased in areas of high riparian forest cover, far from hunting concessions and with more pastoralist activities. Hyaena occupancy was inversely related to anthropogenic pressures, and positively related to dense vegetation and overall prey density. We discuss conservation challenges such as illegal hunting and grazing in the context of transboundary management.

We studied the sett characteristics and habitat variables of the Asian badger Meles leucurus in a temperate forest in South Korea. Logistic regression models were utilized to explain the effects of habitat variables on the location of badger setts. The presence of rocks and trees nearby and of dense ground vegetation and sub-overstory vegetation were correlated positively with sett location. Abundance of setts was higher in deciduous forest compared with coniferous forest, mixed forest and non-forest. The animals showed a preference for a steeper slope of sett location, which likely allows for easier removal of soil during sett settling, as well as improved drainage in that area. In low and high altitudinal areas disturbed by humans, a lower abundance of setts was found. Thus, selection of sett location was strongly influenced by structures around the setts, vegetation cover, forest type, slope and altitude. These variables should be considered and handled carefully though forest management for the conservation of the mammals and their habitats.