Expanding human development and climate change are dramatically altering habitat conditions for wildlife. While the initial response of wildlife to changing environmental conditions is typically a shift in behaviour, little is known about the effects of these stressors on hibernation behaviour, an important life‐history trait that can subsequently affect animal physiology, demography, interspecific interactions and human‐wildlife interactions. Given future trajectories of land use and climate change, it is important that wildlife professionals understand how animals that hibernate are adapting to altered landscape conditions so that management activities can be appropriately tailored. We investigated the influence of human development and weather on hibernation in black bears (Ursus americanus), a species of high management concern, whose behaviour is strongly tied to natural food availability, anthropogenic foods around development and variation in annual weather conditions. Using GPS collar data from 131 den events of adult female bears (n = 51), we employed fine‐scale, animal‐specific habitat information to evaluate the relative and cumulative influence of natural food availability, anthropogenic food and weather on the start, duration and end of hibernation. We found that weather and food availability (both natural and human) additively shaped black bear hibernation behaviour. Of the habitat variables we examined, warmer temperatures were most strongly associated with denning chronology, reducing the duration of hibernation and expediting emergence in the spring. Bears appeared to respond to natural and anthropogenic foods similarly, as more natural foods, and greater use of human foods around development, both postponed hibernation in the fall and decreased its duration. Synthesis and applications. Warmer temperatures and use of anthropogenic food subsides additively reduced black bear hibernation, suggesting that future changes in climate and land use may further alter bear behaviour and increase the length of their active season. We speculate that longer active periods for bears will result in subsequent increases in human–bear conflicts and human‐caused bear mortalities. These metrics are commonly used by wildlife agencies to index trends in bear populations, but have the potential to be misleading when bear behaviour dynamically adapts to changing environmental conditions, and should be substituted with reliable demographic methods.
Information garnered from the capture and handling of free-ranging animals helps advance understanding of wildlife ecology and can aid in decisions on wildlife management. Unfortunately, animals may experience increased levels of stress, injuries, and death resulting from captures (e.g., exertional myopathy, trauma). Partial sedation is a technique proposed to alleviate stress in animals during capture, yet efficacy of partial sedation for reducing stress and promoting survival post-capture remains unclear. We evaluated the effects of partial sedation on physiological, biochemical, and behavioral indicators of acute stress and probability of survival post-capture for mule deer (Odocoileus hemionus) that were captured via helicopter net-gunning in the eastern Greater Yellowstone Ecosystem, Wyoming, USA. We administered 10-30 mg of midazolam and 15 mg of azaperone intramuscularly (IM) to 32 mule deer in 2016 and 53 mule deer in 2017, and maintained a control group (captured but not sedated) of 38 mule deer in 2016 and 54 mule deer in 2017. To evaluate indicators of acute stress, we measured heart rate, blood-oxygen saturation, body temperature, respiration rate, and levels of serum cortisol. We recorded number of kicks and vocalizations of deer during handling and evaluated behavior during release. We also measured levels of fecal glucocorticoids as an indicator of baseline stress. Midazolam and azaperone did not reduce physiological, biochemical, or behavioral indicators of acute stress or influence probability of survival post-capture. Mule deer that were administered midazolam and azaperone, however, were more likely to hesitate, stumble or fall, and walk during release compared with individuals in the control group, which were more likely to trot, stot, or run without stumbling or falling. Our findings suggest that midazolam (10-30 mg IM) and azaperone (15 mg IM) may not yield physiological or demographic benefits for captured mule deer as previously assumed and may pose adverse effects that can complicate safety for captured animals, including drug-induced lethargy. Although we failed to find efficacy of midazolam and azaperone
COVID-19 lockdowns in early 2020 reduced human mobility, providing an opportunity to disentangle its effects on animals from those of landscape modifications. Using GPS data, we compared movements and road avoidance of 2300 terrestrial mammals (43 species) during the lockdowns to the same period in 2019. Individual responses were variable with no change in average movements or road avoidance behavior, likely due to variable lockdown conditions. However, under strict lockdowns 10-day 95th percentile displacements increased by 73%, suggesting increased landscape permeability. Animals’ 1-hour 95th percentile displacements declined by 12% and animals were 36% closer to roads in areas of high human footprint, indicating reduced avoidance during lockdowns. Overall, lockdowns rapidly altered some spatial behaviors, highlighting variable but substantial impacts of human mobility on wildlife worldwide.
Site fidelity—the tendency to return to previously visited locations—is widespread across taxa. Returns may be driven by several mechanisms, including memory, habitat selection, or chance; however, pattern‐based definitions group different generating mechanisms under the same label of ‘site fidelity’, often assuming memory as the main driver. We propose an operational definition of site fidelity as patterns of return that deviate from a null expectation derived from a memory‐free movement model. First, using agent‐based simulations, we show that without memory, intrinsic movement characteristics and extrinsic landscape characteristics are key determinants of return patterns and that even random movements may generate substantial probabilities of return. Second, we illustrate how to implement our framework empirically to establish ecologically meaningful, system‐specific null expectations for site fidelity. Our approach provides a conceptual and operational framework to test hypotheses on site fidelity across systems and scales.
Climate warming creates energetic challenges for endothermic species by increasing metabolic and hydric costs of thermoregulation. Although endotherms can invoke an array of behavioural and physiological strategies for maintaining homeostasis, the relative effectiveness of those strategies in a climate that is becoming both warmer and drier is not well understood. In accordance with the heat dissipation limit theory which suggests that allocation of energy to growth and reproduction by endotherms is constrained by the ability to dissipate heat, we expected that patterns of habitat use by large, heat‐sensitive mammals across multiple scales are critical for behavioural thermoregulation during periods of potential heat stress and that they must invest a large portion of time to maintain heat balance. To test our predictions, we evaluated mechanisms underpinning the effectiveness of bed sites for ameliorating daytime heat loads and potential heat stress across the landscape while accounting for other factors known to affect behaviour. We integrated detailed data on microclimate and animal attributes of moose Alces alces, into a biophysical model to quantify costs of thermoregulation at fine and coarse spatial scales. During summer, moose spent an average of 67.8% of daylight hours bedded, and selected bed sites and home ranges that reduced risk of experiencing heat stress. For most of the day, shade could effectively mitigate the risk of experiencing heat stress up to 10°C, but at warmer temperatures (up to 20°C) wet soil was necessary to maintain homeostasis via conductive heat loss. Consistent selection across spatial scales for locations that reduced heat load underscores the importance of the thermal environment as a driver of behaviour in this heat‐sensitive mammal. Moose in North America have long been characterized as riparian‐obligate species because of their dependence on woody plant species for food. Nevertheless, the importance of dissipating endogenous heat loads conductively through wet soil suggests riparian habitats also are critical thermal refuges for moose. Such refuges may be especially important in the face of a warming climate in which both high environmental temperatures and drier conditions will likely exacerbate limits to heat dissipation, especially for large, heat‐sensitive animals.
Elucidating factors that contribute to citation rates of scientific articles can help scientists write manuscripts that have a stronger influence on their scientific field and are accessible to a broad audience. Using a cohort of 778 articles published in The Journal of Wildlife Management from 2011–2015, we examined how visibility strategies, article structure, and focal system (all factors authors can predominantly control) influenced the accumulation of citations over various time frames within the first 5 years after publication, and the number of days until an article received its first citation. Visibility strategies (e.g., open access, increasing the Altmetric Attention Score, and self‐citations) all influenced the number of citations accrued following publication. Citations were more stochastic 1 year following publication compared to 5 years following publication, with only 20.1% of papers receiving a citation after 1 year compared to 92.5% of papers receiving a citation after 5 years. Our model explained much more of the variation after 5 years compared to after only 1 year (R2 = 0.57 and 0.12, respectively). The number of factors significantly associated with citation rates increased as the timeframe of our analysis increased. After 5 years, factors associated with article structure (e.g., number of references), focal system (e.g., methods papers), and visibility all increased citation counts of papers. Our work suggests citation rates within wildlife ecology are influenced by a number of controllable factors, and that authors pursuing a variety of visibility strategies can increase the influence of an article on science and management.
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