Metabolic rate of the red panda, Ailurus fulgens, a dietary bamboo specialist

Comparative Transcriptomics and Methylomics Reveal Adaptive Responses of Digestive and Metabolic Genes to Dietary Shift in Giant and Red Pandas

Both the giant panda (Ailuropoda melanoleuca) and red panda (Ailurus fulgens) belong to the order Carnivora, but have changed their dietary habits to eating bamboo exclusively. The convergent evolution characteristics of their morphology, genome and gut flora have been found in the two pandas. However, the research on the convergent adaptation of their digestion and metabolism to the bamboo diet, mediated by the dietary shift of the two pandas at the gene-expression and epigenetic regulation levels, is still lacking. We therefore used RNA sequencing among five species (two pandas and three non-herbivore mammals) and bisulfite sequencing among three species (two pandas and a carnivore ferret) to sequence key digestion and metabolism tissues (stomach and small intestine). Our results provide evidence that the convergent differentially expressed genes (related to carbohydrate utilization, bile secretion, Lys and Arg metabolism, vitamin B12 utilization and cyanide detoxification) of the two pandas are adaptive responses to the bamboo diet containing low lipids, low Lys and Arg, low vitamin B12 and high cyanide. We also profiled the genome-wide methylome maps of giant panda, red panda and ferret, and the results indicated that the promoter methylation of the two pandas may regulate digestive and metabolic genes to adapt to sudden environmental changes, and then, transmit genetic information to future generations to evolve into bamboo eaters. Taken together, our study provides new insights into the molecular mechanisms of the dietary shift and the adaptation to a strict bamboo diet in both pandas using comparative transcriptomics and methylomics.

Reaching over the gap: A review of trends in and status of red panda research over 193 years (1827-2020)

The red panda is a unique species taxonomically known for its peculiar biological and ecological characteristics, and extreme attractiveness. Despite being highly significant from conservation, scientific and economic perspectives, this species has experienced a declining population in the wild. Thus, to direct further research priorities and conservation actions and assess gaps in the current research trend of this species, a systematic literature review was conducted covering 175 journal articles published in English over 193 years (1827-2020). This review revealed that (1) the biological aspect was highly studied compared to other thematic areas of red panda (2) captive-based studies are relatively higher than the studies based in wild populations (3) China is leading the red panda studies amongst all red panda range (4) The universities were found contributing more to red panda studies than other institutions. Surprisingly, we found that the researchers from the non-range country were leading red panda study than those from range countries. Our review highlighted the need of prioritising studies in underrepresented locations and understudied thematic areas focusing on the assessment of climate change impact, bamboo distribution status, ecosystem services of red panda habitat, behavior and movement ecology, population estimation, and metapopulation dynamics. We urge landscape-level studies and long-term population monitoring. Besides, we also suggest the documentation and evaluation of the effectiveness of ongoing red panda-focused conservation programs. We also stress the need for strengthening the capacity of institutions and people from range countries.

Landscape variables affecting the Himalayan red panda Ailurus fulgens occupancy in wet season along the mountains in Nepal

The Himalayan red panda is an endangered mammal endemic to Eastern Himalayan and South Western China. Data deficiency often hinders understanding of their spatial distribution and habitat use, which is critical for species conservation planning. We used sign surveys covering the entire potential red panda habitat over 22,453 km² along the mid-hills and high mountains encompassing six conservation complexes in Nepal. To estimate red panda distribution using an occupancy framework, we walked 1,451 km along 446 sampled grid cells out of 4,631 grid cells in the wet season of 2016. We used single-species, single-season models to make inferences regarding covariates influencing detection and occupancy. We estimated the probability of detection and occupancy based on model-averaging techniques and drew predictive maps showing site-specific occupancy estimates. We observed red panda in 213 grid cells and found covariates such as elevation, distance to water sources, and bamboo cover influencing the occupancy. Red panda detection probability p^(SE) estimated at 0.70 (0.02). We estimated red panda site occupancy (sampled grid cells) and landscape occupancy (across the potential habitat) Ψ^(SE) at 0.48 (0.01) and 0.40 (0.02) respectively. The predictive map shows a site-specific variation in the spatial distribution of this arboreal species along the priority red panda conservation complexes. Data on their spatial distribution may serve as a baseline for future studies and are expected to aid in species conservation planning in priority conservation complexes.

Characteristics of Mesenchymal Stem Cells Isolated from the Bone Marrow of Red Pandas

Mesenchymal stem cells (MSC) have strong therapeutic potential due to their capacity for self-renewal and multilineage differentiation. MSCs can also be useful in preserving the current genetic diversity of endangered wildlife. To date, MSCs from various species have been studied, but only a few species of endangered wild animals have been reported. Adult bone marrow (BM) is a rich source of mesenchymal stem cells. The aim of this study was to isolate and characterize MSCs derived from the BM of red pandas. Red panda BM-MSCs isolated from five individuals were fibroblast-like cells, similar to other species. Cultured BM-MSCs with normal karyotype were negative for the hematopoietic line marker CD34 and the endothelial cell marker CD31 but were positive for MSC markers, including CD44, CD105 and CD90. RT-PCR and western blot analysis showed self-renewal and pluripotency genes, including Oct4, Sox2 and Klf4, were also expressed in red panda BM-MSCs. Finally, red panda BM-MSCs had the potential for differentiation into osteogenic, adipogenic and neuron-like cells by using a combination of previously reported protocols for other species. We have therefore demonstrated that cells harvested from red panda bone marrow are capable of extensive in vitro multiplication and multilineage differentiation, which is an essential step toward their use in the preservation of red pandas biological diversity and future studies on MSC applications in endangered species.

An assessment of human impacts on endangered red pandas (Ailurus fulgens) living in the Himalaya

Anthropogenic factors play an important role in shaping the distribution of wildlife species and their habitats, and understanding the influence of human activities on endangered species can be key to improving conservation efforts as well as the implementation of national strategies for sustainable development. Here, we used species distribution modeling to assess human impacts on the endangered red panda (Ailurus fulgens) in high-altitude regions of Nepal. We found that the distance to paths (tracks used by people and animals), livestock density, human population density, and annual mean temperature were the most important factors determining the habitat suitability for red pandas in Nepal. This is the first study that attempts to use comprehensive environmental and anthropogenic variables to predict habitat suitability for the red pandas at a national level. The suitable habitat identified by this study is important and could serve as a baseline for the development of conservation strategies for the red panda in Nepal.

Red panda fine-scale habitat selection along a Central Himalayan longitudinal gradient

Red panda Ailurus fulgens, an endangered habitat specialist, inhabits a narrow distribution range in bamboo abundance forests along mountain slopes in the Himalaya and Hengduan Mountains. However, their habitat use may be different in places with different longitudinal environmental gradients, climatic regimes, and microclimate. This study aimed to determine the habitat variables affecting red panda distribution across different longitudinal gradients through a multivariate analysis. We studied habitat selection patterns along the longitudinal gradient in Nepal's Himalaya which is grouped into the eastern, central, and western complexes. We collected data on red panda presence and habitat variables (e.g., tree richness, canopy cover, bamboo abundance, water availability, tree diameter, tree height) by surveys along transects throughout the species' potential range. We used a multimodal inference approach with a generalized linear model to test the relative importance of environmental variables. Although the study showed that bamboo abundance had a major influence, habitat selection was different across longitudinal zones. Both canopy cover and species richness were unimportant in eastern Nepal, but their influence increased progressively toward the west. Conversely, tree height showed a decreasing influence on habitat selection from Eastern to Western Nepal. Red panda's habitat selection revealed in this study corresponds to the uneven distribution of vegetation assemblages and the dry climatic gradient along the eastern-western Himalayas which could be related to a need to conserve energy and thermoregulate. This study has further highlighted the need of importance of bamboo conservation and site-specific conservation planning to ensure long-term red panda conservation.

Habitat overlap between Asiatic black bear Ursus thibetanus and red panda Ailurus fulgens in Himalaya

Studying habitat overlap between sympatric species is one of the best ways to identify interspecies relationships and to direct conservation efforts so that multiple species can benefit. However, studies exploring interspecies relationships are very limited in Nepal, making it difficult for the government of Nepal and conservation partners to manage wildlife in their habitats, especially in Himalayan protected areas. In this study, we identified habitat overlap between Asiatic black bear (Ursus thibetanus) and red panda (Ailurus fulgens) as well as important habitat types for both species in the Makalu Barun National Park, Nepal using Maximum Entropy (MaxEnt) modeling. GPS points of species occurrence were collected from the field, and environmental variables were extracted from freely available sources. We found that the study area contained 647 km2 of Asiatic black bear habitat and 443 km2 of the red panda habitat. 368 km2 supported both species, which constituted 57% of the Asiatic black bear habitat and 83% of the red panda habitat. We found that conifer forest was the most important habitat type for both species. Because the largest portions of both species' habitat were located inside the buffer zone, a peripheral zone of national park, conservation efforts for these sympatric species should be focused inside the buffer zone to be most effective.

Microbial Biogeography Along the Gastrointestinal Tract of a Red Panda

The red panda (Ailurus fulgens) is a herbivorous carnivore that is protected worldwide. The gastrointestinal tract (GIT) microbial community has widely acknowledged its vital role in host health, especially in diet digestion; However, no study to date has revealed the GIT microbiota in the red panda. Here, we characterized the microbial biogeographical characteristics in the GIT of a red panda using high-throughput sequencing technology. Significant differences were observed among GIT segments by beta diversity of microbiota, which were divided into four distinct groups: the stomach, small intestine, large intestine, and feces. The stomach and duodenum showed less bacterial diversity, but contained higher bacterial abundance and the most unclassified tags. The number of species in the stomach and small intestine samples was higher than that of the large intestine and fecal samples. A total of 133 core operational taxonomic units were obtained from the GIT samples with 97% sequence identity. Proteobacteria (52.16%), Firmicutes (10.09%), and Bacteroidetes (7.90%) were the predominant phyla in the GIT of the red panda. Interestingly, Escherichia-Shigella were largely abundant in the stomach, small intestine, and feces whereas the abundance of Bacteroides in the large intestine was high. Overall, our study provides a deeper understanding of the gut biogeography of the red panda microbial population. Future research will be important to investigate the microbial culture, metagenomics and metabolism of red panda GIT, especially in Escherichia-Shigella.

Keratomycosis in captive red pandas (Ailurus fulgens): 2 cases

Two cases of keratomycosis in captive red pandas (Ailurus fulgens) were diagnosed and treated at a zoo in Melbourne, Australia across a 9-year period. Both cases presented with severe unilateral ocular pain and stromal abscessation of the cornea. A superficial keratectomy was performed in both cases and the diagnosis was confirmed with either cytology or histopathology. Following surgery, a combination of oral, topical and subconjunctival medical therapy contributed to a successful outcome.