We are pleased to share these recent URSUS articles with you. Both articles are open access and can also be accessed through your IBA membership account link to BioOne.
Grizzly bear behavior in south-central Alaska: Use of a hidden Markov model to assess behavior
Amanda M. Mumford, Jeffrey Stetz, Dominic Demma, Roman Dial, Jeffrey M. Welker
Ursus 2024 (35e22), 1-19, (18 November 2024) https://doi.org/10.2192/URSUS-D-23-00004R1
KEYWORDS: animal behavior, global navigation satellite systems, GNSS data, GPS collars, grizzly bear, hidden markov model, Ursus arctos, wildlife management
Open Access Article
Attempts to understand wildlife population dynamics and implement management practices benefit from understanding animal behavior traits. In Alaska, USA, grizzly bear (Ursus arctos) behavior is important to understand because the species is an apex predator, exerts top-down population effects, and is a cornerstone species across complex landscapes. Our objectives were to examine how environmental and anthropogenic factors affect behavior patterns in grizzly bears in south-central Alaska. We hypothesized that, for a given sex, the time spent by bears resting, foraging, and traveling are similar and show consistent seasonal shifts as resource availability changes throughout their nondenning season. Additionally, we hypothesized that males spend more time traveling than do females because of differences in home range sizes, metabolic needs, and the rearing of cubs associated with females. We used a hidden Markov model (HMM) to test our hypotheses and examine how various dynamic, static, and temporal variables affected bear (n = 12) behavior during the summers of 2021–2022. Males spent the most time foraging and the least time resting while females spent the most time resting and the least time foraging. These patterns shifted as the summer progressed with increases in traveling and foraging and decreases in resting for both sexes. Bears were found to be most likely in a resting state at hotter temperatures and more likely to be traveling at colder temperatures. Additionally, bear behaviors deviated depending on elevation, whereby bears were foraging at higher elevations and resting or traveling at lower elevations. Our findings indicate that male–female differences in behavior are seasonally dependent, being similar in autumn and opposite during the postdenning period. In addition, we see evidence that changes in environmental conditions, such as warming, can have direct effects on behavior. Further studies should explore how future environmental and anthropogenic factors such as predicted changes in climate and increases in land-use changes can affect bear behavior and subsequent demographic effects.
Habitat selection by the Himalayan brown bear in the multiuse landscape of Lahaul Valley, India
Vineet Kumar, Amira Sharief, Hemant Singh, Ritam Dutta, Bheem Dutt Joshi, Mukesh Thakur, Bhupendra Singh Adhikari, Lalit Kumar Sharma
Ursus 2024 (35e23), 1-10, (28 November 2024) https://doi.org/10.2192/URSUS-D-24
KEYWORDS: Camera trap, Generalized linear model, habitat use, Himalayan brown bear, India, nonprotected area, resource selection, Ursus arctos isabellinus
Open Access Article
The Himalayan brown bear (Ursus arctos isabellinus) is the largest carnivore in the Himalayan Mountain range of India, Pakistan, and Afghanistan. Distinguished by its exclusive occurrence in mountain landscapes within the Himalayas, this species is threatened by anthropogenic pressure, habitat degradation, and climate change. There is limited understanding of the habitat requirements of the Himalayan brown bear in India, so we used camera traps and sign surveys conducted from July 2018 to December 2022 to address this knowledge gap, focusing on the influence of ecogeographic variables on Himalayan brown bear habitat use within the Lahaul Valley of India. Employing a generalized linear model using presence and randomly generated pseudoabsence locations, we found a positive relationship of Himalayan brown bear habitat use with annual precipitation, the largest patch index, the Shannon diversity index, and slope. Conversely, a negative association was observed with elevation and precipitation in the driest month. The study found Himalayan brown bear preference for larger, interconnected habitat patches, highlighting the significance of these areas for resources and connectivity. Himalayan brown bear predicted presence is mainly in the subalpine and alpine regions at 2,500 m to 4,500 m elevation. Moderate to steep slopes are preferred by Himalayan brown bears, consistent with den site preferences and habitat use patterns. Resource Selection Index outcomes reveal a strong affinity for forests, and reduced use of rangeland. Given the absence of protected areas in the study landscape and prevailing threats of habitat loss to agricultural expansion, livestock grazing, and roads development, we emphasize the urgency of identifying and connecting ideal habitat patches to ensure the conservation of the Himalayan brown bear in the Lahaul Valley and adjoining areas.