Understanding coexistence mechanisms among sympatric large carnivores is critical for their conservation, particularly in human-modified mountain landscapes where ecological information remains limited. We investigated the spatiotemporal and dietary dynamics between the Asiatic black bear (Ursus thibetanus) and the Himalayan brown bear (Ursus arctos isabellinus) in the anthropogenically influenced landscape of Dhauladhar Wildlife sanctuary situated in the Greater Himalayas. Using two years of camera-trap data (2023-2024) combined with scat analysis, we examined seasonal patterns of habitat use, activity rhythms, food habits, and responses to human settlements within a multidimensional niche framework. We found that spatial overlap between the species varied seasonally, being lowest in spring, moderate in summer, highest in autumn, and absent in pre-winter or peak hyperphagia, while temporal overlap showed an inverse pattern indicating fine-scale temporal segregation as a mechanism to minimize direct encounters. Proximity to human settlements influenced activity patterns of Asiatic black bears, which exhibited increased nocturnality near disturbed areas, whereas Himalayan brown bears maintained relatively stable activity patterns and primarily occupied alpine and subalpine habitats away from human influence. Dietary analyses revealed predominantly plant-based diets for both the species, with pronounced seasonal shifts driven by resource phenology. Dietary overlap also varied seasonally, with clear segregation in spring and increasing overlap from summer to pre-winter. We demonstrated that the coexistence between these sympatric bears is maintained through seasonally dynamic partitioning across spatial, temporal, and trophic niche dimensions. The simultaneous integration of these niche axes within a single multidimensional space emphasizes the benefit of moving away from single-axis approaches in community ecology, and provides an empirical test of the partitioning of coexistence by large sympatric omnivores dynamically across seasons in a human-modified landscape. The sanctuary supports a largely intact natural foraging system, highlighting the importance of maintaining habitat heterogeneity and minimizing human disturbance for long-term bear conservation.
Although the Eurasian otter (Lutra lutra) is highly sensitive to urbanization, its occurrence in urban areas has recently increased. Few studies have examined the sprainting behavior of urban otters in response to environmental conditions. We aimed to determine which environmental factors best explain otter sprainting behavior and quantify seasonal shifts in their spatial distribution. Accordingly, we conducted seasonal otter spraint surveys along the Gwangju Stream, an urban stream in South Korea, over 2020–2021, and used spraint marking intensity indicators (spraint and latrine site counts) to test two hypotheses: (1) riverine habitat structure accounts for a larger proportion of variance in sprainting behavior than human population size, land use, and water quality, and (2) the spatial distribution of sprainting behavior becomes more uneven among survey sites during autumn and winter than during spring and summer. To test our first hypothesis, we selected a refined set of variables related to riverine habitat structure, human population size and land use, and water quality to perform variance partitioning. Subsequently, we evaluated eight candidate negative binomial generalized linear models, including a temporal baseline model, in terms of the best fit. We tested the second hypothesis using seasonal sprainting patterns and coefficients of variation. Riverine habitat structure made a substantially larger contribution to explaining sprainting behavior than human population size and land use or water quality. Models incorporating riverine habitat structure provided the best fit for both spraint intensity indicators. Artificial structures had positive effects on both spraint sites and latrines, while water areas and gravel pits were positively associated with spraint sites. In contrast, human population size and water depth had negative effects on latrines. Seasonal coefficients of variation suggested that sprainting behavior tended to become more spatially uneven among survey sites during autumn and winter. While mitigating basic water quality and human population and land use pressures is required for otter occurrence, suitable riverine habitat structure is the primary driver facilitating successful coexistence in urban streams. Identifying seasonal constraints on habitat use provides crucial insights for developing site-specific conservation strategies for urban otter populations.
Acoustic communication in anurans involves specialised structures associated with sound production and reception, including the vocal apparatus and tympanum, respectively. Sexual differences in these structures may reflect variation in overall body size or sex-specific structural differentiation. However, information regarding sexual dimorphism in acoustic-related morphology remains limited for Bornean ranids, particularly in Hylarana raniceps. This study investigated sexual dimorphism in the tympanum and vocal apparatus morphology of H. raniceps from Sarawak, Malaysian Borneo. A total of 24 individuals collected from Gunung Mulu National Park, Gunung Gading National Park, Ranchan Recreational Park, Kubah National Park, and Simunjan Forest Reserve were examined. Morphological observations and morphometric measurements were obtained for the tympanum, snout-vent length (SVL), and tibia length (TL). Five linear measurements of the vocal apparatus were obtained after histological processing using Haematoxylin and Eosin staining. Male H. raniceps exhibited larger vocal apparatus structures, whereas females possessed larger body size, tibia length, and tympanum dimensions. The sexual dimorphism index (SDI) indicated male-biased vocal apparatus measurements and female-biased body size and tympanum measurements. Histological observations revealed apparently greater development of the surrounding musculature in males; however, muscle thickness was not directly quantified. ANCOVA showed that tympanum morphology was strongly associated with SVL (p < 0.001), with significant sex × SVL interactions indicating sex-specific allometric relationships. Several vocal apparatus traits (PVPM and CPEP) remained significantly different between sexes after accounting for body size variation, providing evidence of sexual shape dimorphism. Principal component analysis showed that PC1 explained 92.17
Legacy natural-history collections can provide auditable faunal baselines, but the biodiversity patterns they contain may also reflect uneven collecting histories. Using taxonomically verified Sarcophagidae from the Lakes Region of southwestern Türkiye, we integrated voucher linkage, taxonomic and spatial harmonization, reconstruction of sampling history, and sensitivity analysis to determine what the collection documents, quantify how temporal sampling replication relates to recorded richness, and interpret associated faunal patterns within that sampling framework. The collection comprised 202 occurrence records and 300 preserved voucher specimens from 73 source-defined sampling locations and 57 canonical locality units across four provinces (Afyonkarahisar, Antalya, Burdur, and Isparta). Of these, 201 occurrences and 299 vouchers were identified to species, representing 37 species at 72 locations. Sampling was highly uneven: 80.7
Vultures play an indispensable ecological role in maintaining ecosystem balance through the rapid removal of carrion and the provision of critical ecosystem services. Of the 16 Old World vulture species, Africa supports 11, with eight species recorded in Ethiopia. However, urbanization and associated anthropogenic pressures may threaten these essential scavengers. This study assessed vulture species composition, observed abundance, seasonal variation, and conservation threats in Jimma City, southwestern Ethiopia, during the dry season (January–March) and wet season (May–July) of 2022. Data were collected through systematic field observations, questionnaire surveys, and key informant interviews and were analyzed using SPSS version 26. Four globally threatened species were recorded: hooded, white-backed, rüppell’s griffon, and lappet-faced vultures, underscoring the urgent need for targeted conservation interventions. Vulture counts varied significantly between seasons (P < 0.001), with higher counts recorded during the wet season. Mean dry-season counts were 264 ± 9 for hooded, 191 ± 29 for African white-backed, 17 ± 3 for Rüppell’s griffon, and 4 ± 1 for lappet-faced vultures. The corresponding wet-season counts were 408 ± 57, 266 ± 25, 29 ± 4, and 7 ± 1, respectively. The hooded vulture had the highest relative abundance, accounting for 57
