The olfactory receptor (OR) gene family is the largest in mammals, with its repertoire size and functional status tightly linked to ecological adaptation. Here, we systematically identified and compared OR genes in 25 carnivoran species, including both marine and terrestrial carnivores, to investigate evolutionary patterns under different ecological backgrounds. Marine carnivores exhibit a significant reduction in OR gene numbers and an increased proportion of pseudogenes, consistent with diminished reliance on olfaction in aquatic environments. Strikingly, giant panda—despite being terrestrial—shows a similar genomic signature, with reduced OR gene numbers and high pseudogene proportions. Phylogenetic and selective stress analyses revealed that both giant pandas and Marine carnivores experienced the loss of OR genes and weakened functional constraints. Principal component and regression analyses further demonstrate that dietary specialization and restricted ecological niches are likely major drivers of OR gene evolution. Collectively, these findings suggest that the degeneration of giant panda’s OR genes is closely tied to its unique ecological niche and resembles patterns observed in marine carnivores, providing new insights into the ecological drivers of sensory genome evolution.

Gut microbiome gene catalogues have advanced the knowledge of host-microbiome interactions in many mammals. Snub-nosed monkeys (Rhinopithecus spp) are folivores with foregut fermentation which is similar to ruminants, but their gut microbiota lacks a comprehensive description. In this study, we constructed a comprehensive gene catalogue by performing metagenomic analysis on 143 wild snub-nosed monkeys and compare it to that of ruminants and monogastric animals. Our results demonstrate the classification and functional characteristics of the gut microbiome of snub-nosed monkeys and identified a set of core genera in these mammals. Moreover, we found that the gut of snub-nosed monkeys and other herbivores was enriched with more bacteria and enzymes related to the degradation of structural carbohydrates, indicating the importance of gut microbiota for dietary adaptation. Our study expands resources for gut microbiome studies of nonhuman primates and provide new insights into the evolutionary route of foregut fermenting animals during dietary adaptation.

Human activity is increasingly and persistently disturbing nature and wild animals. Affected wildlife adopts multiple strategies to deal with different human influences. To explore the effect of human activity on habitat utilization of Himalayan marmot (Marmota himalayana), habitat utilization patterns of three neighboring marmot populations in habitats affected differently by human activities were recorded and compared. We found that: (1) Distance between reproductive burrows (a represent of reproductive pairs) becomes shorter under the influence of human activities, and more burrows were dug as temporary shelters, resulting in a shorter distance between those shelters as well as shorter distance flee to those shelters, and consequently, shorter flight initiation distance when threatened. More burrows that are closer in the disturbed habitats improve the ability to escape from threats. (2) Reproductive burrow site selection of the species is determined by the availability of mounds in the habitat, and breeding pairs selectively build reproductive (also the hibernation) burrows on mounds, potentially to improve surveillance when basking and the drainage of burrows. Human activities generally drive breeding pairs away from the road to dig their reproductive burrows likely to reduce disturbance from vehicles. However, even heavy human activity exerts no pressure on the distance of reproductive burrows from the road or the mound volume of the high disturbance population, potentially because mounds are the best burrowing site to reproduce and hibernate in the habitat. Marmots deal with disturbance by digging more burrows in the habitat to flee more effectively and building reproductive burrows on mounds to gain better vigilance and drainage efficiency.

Human activity is increasingly and persistently disturbing nature and wild animals. Affected wildlife adopts multiple strategies to deal with different human influences. To explore the effect of human activity on habitat utilization of the Himalayan marmot (Marmota himalayana), habitat utilization patterns of three neighboring marmot populations in habitats affected differently by human activities were recorded and compared. We found that: (1) Distance between reproductive burrows becomes shorter under the influence of human activity, and further, the more disturbance a population suffers, the more burrows were dug as temporary shelter to reduce the distance to those shelters when threatened. More burrows that are closer in the disturbed habitats improve ability to escape from threats. (2) Burrow site selection is determined by the availability of mounds in the habitat. Breeding pairs selectively build burrows on mounds to reproduce, potentially to improve surveillance and the drainage of their burrows. Human activities generally drive breeding pairs away from the road to build their reproductive burrows, likely to reduce disturbance from vehicles. However, even heavy human activity exerts no pressure on the distance of reproductive burrows from the road or the mound volume of the high disturbance population, potentially because mounds are the best burrowing site in the habitat. Marmots deal with nonlethal human disturbance by digging more burrows in the habitat to flee more effectively and building reproductive burrows on mounds to gain better vigilance and drainage efficiency.

Versatile counterstrategies shift the balance of intersexual conflict from males to females