Journal of Wildlife Management最新文献

Sarcoptic mange is an emerging parasitic disease affecting North American black bears (Ursus americanus) and has been increasingly reported since the early 1990s. As mange spreads into naive bear populations, wildlife managers face challenges related to surveillance, interagency coordination, and stakeholder expectations. In 2023, we surveyed 35 state and federal wildlife agency personnel and academic partners to assess management practices for mange, barriers to effective interventions, and how agencies engage with the public and key stakeholders. Respondents represented 17 states, 7 with and 10 without reports of sarcoptic mange in black bears, with over half (51.4%) working in their current institution for more than 10 years. Respondents generally agreed on dispatching severely affected wildlife (97.1%) and monitoring mild to moderate cases. Although respondents supported stakeholder and public reporting of mange cases (71.4%), they opposed stakeholder and public intervention in mange management (e.g., treatment, handling, relocation). Fewer than half of respondents (45.7%) indicated that mange reports are entered into a formal dataset, limiting long-term surveillance and decision-making. Our study highlights the need for a unified multi-state communication framework to increase public support for agency management actions, and the importance of implementing a centralized mange data repository to enhance long-term surveillance of mange and improve response efforts.

Caribou (Rangifer tarandus) calf mortality during the neonatal period is commonly attributed to predation, particularly by gray wolves (Canis lupus). However, neonate mortality remains understudied in mountain caribou, despite increasing wolf reduction programs. We used an individual-based movement method to infer parturition and neonate mortality from adult female telemetry data (78 individual-years), supplemented with 3 years of camera trap data (89 cameras), to examine changes in neonate mortality rates, timing, and locations before (2012–2014) and after (2020–2021) wolf reduction, across 2 calving areas (one rugged, another gradual) for the Itcha-Ilgachuz subpopulation in British Columbia, Canada. Given the likely difference in the timing of wolf–neonate overlap between calving areas, we hypothesized that wolf predation would be additive to other mortality sources typically affecting younger neonates (e.g., grizzly bear [Ursus arctos] predation) in the rugged area, but compensatory in the gradual area. Accordingly, we predicted that reducing wolves would increase survival and lower the average mortality age for neonates in the rugged area, with smaller gains in survival and minimal change in average mortality age in the gradual area. After wolf reduction, survival increased 41% in the rugged area but did not improve in the gradual area, resulting in no overall increase in survival at the subpopulation level. Average mortality age decreased in the rugged area from approximately 14 days to 8 days, coinciding with the peak in camera detections of grizzlies and wolverines (Gulo gulo), and remained at approximately 9 days in the gradual area. Mortalities before wolf reduction (i.e., those more likely caused by wolves) were more strongly associated with anthropogenic linear features and treed valley bottoms. Our findings highlight the value of considering habitat-specific mechanisms influencing calf mortality and integrating indirect approaches to address knowledge gaps in prey–predator dynamics.

On the Atlantic and Gulf coasts of the United States, conservation efforts for the American oystercatcher (Haematopus palliatus) commonly focus on improving reproductive success by identifying and managing key threats to nest and chick survival. However, these threats have the potential to change over time. We monitored the reproductive success of American oystercatchers in the Virginia barrier island system, a significant breeding site where annual American oystercatcher productivity has been low since 2016, suggesting evolving drivers of nest and chick survival. We routinely surveyed the nests and broods of breeding pairs from 76 active American oystercatcher territories on Metompkin Island in 2021–2022 and Fisherman Island in 2023. Additionally, we used radio-telemetry to track one chick per brood (n = 45 chicks) and improve our chances of identifying fate. Using models of age-specific daily survival rates, we found that the probability of a nest surviving to hatching was high (0.91 ± 0.08 [SD]), relative to the probability of a chick surviving to fledging (0.51 ± 0.14 [SD]), indicating that low chick survival may be limiting reproductive success at sites in Virginia. Overall, American oystercatcher reproductive success was affected by a complicated set of factors, including flooding from tidal inundation and storm surge during the nesting stage, and the threat of predation from a complex predator community during the nesting and brood-rearing stages. As threats to American oystercatcher reproductive success change in response to climate change and human activities, natural resource managers will need to consider ecosystem-based management strategies to address those threats, such as habitat restoration to assist behavioral adaptation of nesting American oystercatchers to flooding, and control of threats from both mammalian and non-mammalian predators.

Wind is a primary disturbance type in many forests that influences forest processes and dynamics. The degree of impact depends upon storm characteristics and forest composition. Toppled trees increase canopy openness and create unique pit-and-mound microrelief that may provide wildlife habitat. Few studies have examined wildlife use of these structures, especially during the immediate days following disturbance. Therefore, we investigated how vertebrates use newly uprooted longleaf pine (Pinus palustris) trees and examined how patterns of use varied with time and tree characteristics. We used static winching methods to topple 9 live longleaf pine trees to simulate wind disturbance. Within a few days, we deployed 2 camera traps at each tip up and monitored the structure monthly from May through December 2021. We recorded 1,115,453 photos; 2% had vertebrates (n = 22,401), of which 2,413 were independent observations. We identified 48 species that used tip ups to perch, bask, forage, sing, or take refuge. Our analyses of 14 of the most captured species revealed a progression of vertebrate use through time, dominated initially by birds and lizards, followed by amphibians and meso-mammals. Understanding the ecological impacts of wind disturbance will be useful for management and conservation efforts in wind-prone forests facing projected increases in storm frequency and severity. Our results suggest that tip ups are an ephemeral wildlife habitat resource that should be considered in decision making surrounding salvage logging and stump harvesting.

Boreal woodland caribou (Rangifer tarandus caribou) populations are declining because of increasing predation that is ultimately attributed to human-caused landscape alterations and climate change. Bears (Ursus spp.) can be a primary cause of neonate caribou mortality, yet bear–caribou dynamics during the calving season are poorly understood, particularly in western Canada. Using a simulation parameterized by empirical data from black bears (U. americanus) and caribou, we assessed how bear movement, habitat use, and density interact with caribou calving habitat selection to influence predation of caribou neonates. For each simulation, we placed neonates within caribou ranges according to caribou densities and calving dates. We then monitored their fates for 2 weeks, the period during which calves are particularly vulnerable to bear predation. Simulated neonates could be killed when the movement paths of global positioning system (GPS)-collared bears came within a specified detection distance. We multiplied simulated kill rates by known bear abundance to estimate the number of neonates killed by the entire bear population. Simulation results indicated that individual bears rarely kill neonates because of low bear–neonate spatial overlap, but neonatal mortality can still be high owing to the bear densities regularly observed in the boreal forest. Caribou selected habitat during calving that reduced bear predation compared to calving randomly across their range. Recent efforts to conserve caribou have included predator reductions, but our results highlight that such action would be a challenge for black bears because it would require removing a high number of bears, many of which would never encounter a caribou calf.

European forests face severe challenges due to climate change, highlighting the importance of tree species diversity for regeneration. The management of browsing species such as red deer (Cervus elaphus) is therefore crucial. An important metric for managing population size is the adult sex ratio (ASR), for example, derived from camera trap data. In our study, we address 2 issues specific to camera trap methods separately: avoiding the loss of information contained in the proportion of unknown-sex sightings and accounting for sex-specific detection probabilities. Our hypothesis was that these advanced statistical methods reveal a potential bias in the estimation of red deer ASR in a naive approach directly from raw camera trap data. We conducted research in an alpine area of Austria from January 2020 to May 2022. We chose weeks 9 to 17 in spring to obtain pre-hunting and pre-birth data. We included unknown-sex sightings (8.9% of all sightings) with predicted sex (precision of 75%) in the ASR estimation after conducting a model selection process with the goal of the highest precision in prediction. These predicted ASRs showed a non-significant slight shift towards males, indicating a more balanced ASR than a naive ASR. To include sex-specific detection probabilities, we ran a Royle Nichols occupancy model for both sexes and calculated ASR from estimated latent abundances. Contrary to our expectations, there were no significant differences between the occupancy-based ASRs and the naive or predicted ASRs. This suggests that, under the conditions of our study, both the naive approach and more advanced statistical methods yield comparable results in terms of ASR. In the future, this could enable wildlife managers to make informed decisions with minimal effort and cost using tools that do not require complex analysis. If desired, additional ecological information can be derived from advanced statistical methods, such as occupancy modeling, allowing more nuanced interpretations of spatiotemporal behavior.

For many wildlife species, reintroduction is necessary to re-establish populations in areas of their historical range where they have been extirpated, but reintroduction efforts are often expensive, time-consuming, and unsuccessful. A more complete understanding of the factors affecting restoration success is important for responsible stewardship and optimizing outcomes. Fishers (Pekania pennanti) are a commonly reintroduced carnivore in North America, but differences in predator and prey assemblages among release sites may contribute to variation in the success rates of such efforts. We examined how predator and prey occurrence and relative abundance influenced survival rates in reintroduced fisher populations in the southern and northern Cascade Mountains, Washington, USA. We compared survival rates from telemetry data between the 2 areas and used independent detections of prey and predators at 190 remote camera stations to assess how sympatric species related to near-term (1–2 years post-release) fisher survival. We released 81 fishers, of mixed age and sex (majority ≤2 years old), into the South Cascades between December 2015 and January 2020 and released 89 fishers into the North Cascades between December 2018 and February 2020. Using radio-telemetry data, we estimated 365-day post-release survival as 0.65 (95% CI = 0.54–0.79) in the South Cascades and 0.31 (0.21–0.48) in the North Cascades. The relative abundance of important fisher prey species was significantly higher in the South than in the North; notably, snowshoe hares (Lepus americanus) were detected at a rate of 5.11 (±0.86 SE)/100 trap nights in the South versus 1.13 (±0.25)/100 trap nights in the North. Relative abundance of potential fisher predators did not differ significantly between study areas. Our findings are consistent with the survival of reintroduced fishers being affected by differences in prey assemblages across release sites, though other differences between the sites may also play a role in fisher survival. Future reintroduction efforts may benefit from preliminary assessment of prey abundance prior to release site selection.

Participation in wildlife viewing (observing, feeding, or photographing wildlife, or traveling to parks and natural areas to observe, feed, or photograph wildlife) has been growing for decades in the United States, though it is less studied than other wildlife-related activities like hunting and fishing. In this study, we applied frameworks from hunting literature (R3 and Social Habitat for Hunting) to understand participation in wildlife viewing during the first year of the COVID-19 pandemic. These frameworks suggest that participation may be best studied as a series of 4 overlapping scales of social support (macro, meso, micro, and individual) that must be considered in tandem. Using a panel survey of wildlife viewers in the United States, we found 7% of respondents were recruited (began participating for the first time), 56% retained (no change in participation), 24% churned (stopped participating in wildlife viewing), and 13% reactivated (resumed participation in wildlife viewing) during the first year of the COVID-19 pandemic. Recruited wildlife viewers were more likely to be women than retained wildlife viewers, and both recruited and reactivated wildlife viewers were younger and more likely to be Black, Indigenous, or people of color than retained viewers, highlighting the potential for supporting this population to continue diversifying participation in wildlife viewing. We found that, generally, the retained group reported stronger identity as wildlife viewers and received more family support in their participation in wildlife viewing than recruited wildlife viewers, suggesting these levels of support may be influential for continued participation in wildlife viewing. This study implies that the R3 and Social Habitat for Hunting frameworks may be further adapted to support management of wildlife viewing and connecting more people to wildlife.

Forage quality serves as a key indicator of habitat health in protected areas. In the buffer zone of the Huai Kha Khaeng World Heritage Site, a critical habitat for endangered herbivores of Thailand, limited data on forage quality hampers effective habitat management for large herbivores. This study examines seasonal variations in forage quality in the seasonally dry forests of Western Thailand based on 6 surveys conducted in 2018–2019. A nutritional analysis of 55 dominant forage species (12 forbs, 16 shrubs, and 27 tree seedlings) revealed a prolonged annual period (~8–9 months) of low forage quality. Peak nutritive content occurred at the start of the rainy season (April to June), with crude protein (CP) highest in April (16.9%) and lowest in February (10.4%). Forbs consistently provided higher CP (peaking at 16.1% in August), while shrubs contributed more fiber, with neutral detergent fiber (NDF) and acid detergent fiber (ADF) levels rising from 39.9% and 28.8% in April to 45.6% and 38.6% in the late rainy season. Acid detergent lignin (ADL) levels were lowest in April (11.8%) and peaked in August (16.3%). Seasonal shifts in forage quality were reflected in the proportion of species in high-quality (A1) and lower-quality (B1–D3) classes. The A1 forage peaked in April (56.3%, 9 species) but declined sharply by August (8.3%, 1 species). During the dry season, medium- and low-quality forage (B1, C1, D1) predominated. These findings emphasize that integrating forage quality dynamics into habitat management planning can play a key role in supporting the ecological needs of large herbivores and sustaining their long-term populations.