This paper addresses the conservation status of the spectacled bear Tremarctos ornatus in the northern Andes (Venezuela, Colombia and Ecuador) by analysing the degree of range fragmentation and estimating habitat availability. From satellite images we constructed maps of remnant habitat blocks, consisting of Andean forest and páramo (high elevation shrublands and grassland) ecosystems. This information was overlain with a road map to determine potential isolation of populations, and a human accessibility model was used to estimate the core area of each block. This analysis revealed that the species' range is fragmented by landscape transformation and roads into 113 blocks >100 km², representing 42% of the original extent of the bear's distribution. Forty percent of the blocks are 5,000 km². However, taking into account only core area, 56% of the blocks are 5,000 km². In addition, many blocks have internal patches of colonization, further reducing habitat quality. This effect is more severe in smaller fragments, where internal disturbances constitute a high proportion of the block area. We used a high population density estimate of 0.25, a medium density of 0.11 and a low density of 0.04 bears per km² to estimate population sizes. Twenty-nine populations are likely to have >500 individuals with the high estimate, but only nine with the medium and one with the low estimate (largest estimated population was 9,048 bears). These estimates are much lower if only the core area of blocks is used. Hunting has been identified as a major threat for many bear populations. Our analyses indicate that a regional conservation strategy for spectacled bear should focus on maintaining or increasing habitat availability in larger blocks, and reducing human-induced mortality across the region.

Dietary specializations in animals lead to adaptations in morphology, anatomy and physiology. Neotropical bats, with their high taxonomic and trophic diversity, offer a unique perspective on diet-driven evolutionary adaptations. Here we assess the metabolic response to different dietary sugars among wild-caught bats. We found that insectivorous bats had a pronounced metabolic response to trehalose, whereas bats with nectar and fruit-based diets showed significantly higher blood glucose levels in response to glucose and sucrose, reaching levels over 750 mg dl⁻¹. The genomic analysis of 22 focal species and two outgroup species identified positive selection for the digestive enzyme trehalase in insect eaters, while sucrase–isomaltase showed selection in lineages with omnivorous and nectar diets. By examining anatomical and cellular features of the small intestine, we discovered that dietary sugar proportion strongly impacted numerous digestive traits, providing valuable insight into the physiological implications of molecular adaptations. Using hybridization chain reaction (HCR) RNA fluorescence in situ hybridization, we observed unusually high expression in the glucose transporter gene Slc2a2 in nectar bats, while fruit bats increased levels of Slc5a1 and Slc2a5. Overall, this study highlights the intricate interplay between molecular, morphological and physiological aspects of diet evolution, offering new insights into the mechanisms of dietary diversification and sugar assimilation in mammals.