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The giant panda (Ailuropoda melanoleuca) is recognized worldwide as an icon for wildlife conservation. The Qinling subspecies (Ailuropoda melanoleuca qinlingensis) inhabiting the Qinling Mountains is more endangered. Previous studies have indicated that Qinling pandas are potentially at risk from environmental pollutants, which they are exposed to via food and drinking water. However, there is little information about the surface water quality in the Qinling Mountains, and it is unknown whether drinking water is an important pollutant source for pandas. Water samples were collected from five different nature reserves in Qinling, each of which is home to a population of pandas. The samples were analyzed for five essential metals of copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), and nickel (Ni) and four non-essential metals of lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg). The concentrations of all heavy metals (HMs) were higher in buffer zones than in the core areas and were highest in Foping and Niuweihe nature reserves. The concentrations of mercury exceeded the water quality standard in the core zone of three reserves, suggesting that NWH (Niuweihe), THS (Tianhuashan), and PHL (Pingheliang) giant panda populations were at risk from mercury toxicity. The accumulation of other elements over time could also pose a serious risk to pandas. Three main sources of pollution were identified: coal combustion, waste incineration, and fertilizer use; traffic-related activities; and metal mining. Environmental pollution is compromising the efforts to conserve the giant panda, and measures need to be put in place to control pollution sources. [ABSTRACT FROM AUTHOR]

Simple Summary: Giant pandas (Ailuropoda melanoleuca) are a critically endangered relict species, often referred to as a "national treasure" and a "living fossil". China has implemented an ex situ conservation model in order to safeguard and revitalize the population. Given their highly solitary nature, sub-adult giant pandas typically undergo a phase of group living during the ex situ protection process aimed at optimizing space and management efficiency. However, as a solitary species, giant pandas' behavioral responses and physiological performance in social settings remain elusive. This study aims to address these questions by observing the daily behavior of giant pandas through photography and analyzing their cortisol levels and intestinal microbial identification to gain insights into their physiological performance. Based on our current findings, we have determined that the group-rearing model during the sub-adult stage benefits the overall welfare of adult captive giant pandas within their current captive environment. Wild giant pandas are inherently solitary creatures, however, the ex-situ conservation efforts significantly alter the living circumstances of their captive counterparts. Following the breeding period, giant pandas in captivity may be maintained in social groups. Currently, there is a lack of research on the effects of group housing on the physiology, behavior, and gut microbiota of captive giant pandas. This study divided six captive giant pandas into two groups following the breeding period. By comparing the behavior, physiology, and microorganisms of the two groups, we aim to investigate the behavioral responses and physiological adaptation mechanisms exhibited by captive giant pandas in a "group living" state. Our findings indicate that sub-adult giant pandas housed in group settings exhibit a significantly longer duration of playing behavior (including interactive and non-interactive play) compared to their counterparts housed separately (p < 0.001) while also demonstrating a significantly lower duration of stereotyped behavior than their separately housed counterparts. Additionally, an analysis of urine cortisol and heart rate variability between the two groups revealed no significant differences. Simultaneously, the group housing strategy markedly elevated the β diversity of gut microbiota in sub-adult giant pandas. In conclusion, the group-rearing model during the sub-adult stage has been shown to significantly alter the behavioral patterns of captive giant pandas. In conclusion, within the present captive setting, the group-rearing approach during the sub-adult stage proved to be less distressing for adult captive giant pandas. [ABSTRACT FROM AUTHOR]

The reasonable construction of rare animal habitat ecological networks is an important way to maintain the stable development of wild species, and it is of great significance in biodiversity conservation. Based on the habitat suitability perspective, the maximum entropy (MaxEnt) model was used to identify the ecological sources of the Giant Panda National Park; the minimum cumulative resistance (MCR) model and hydrological analysis principles were used to extract the ecological corridors and ecological nodes; the ant colony algorithm and kernel density analysis were introduced to identify the range of corridors and key restoration points; and the ecological network of giant panda habitat was constructed. We evaluated and analyzed the constructed ecological network and pointed out the key areas for ecological protection and restoration. The results show that the habitat suitability of the region as a whole is low, and the spatial differences are obvious. There is a pattern of high values in the east and north and low values in the west and south. 24 ecological sources were extracted, with a total area of 1737.63 km2, mainly distributed in the central and northern regions. 55 ecological corridors were extracted, with a total length of 1667.816 km and a total area of 1312.08 km2, which were widely distributed in the central part of the study area in a network pattern. 23 key ecological corridors and 14 key restoration points were identified, which are areas that should be considered in the construction of national parks in the future. Based on the ecological network characteristics of Giant Panda National Park, the future direction of future ecological restoration in the region was proposed. The research results are expected to provide a reference and basis for the construction of Giant Panda National Park and biodiversity protection. [ABSTRACT FROM AUTHOR]

There has been remarkable progress in the conservation and reproduction of giant pandas. However, the physiology of the gestation period in pandas remains poorly understood. The metabolic processes from estrus to pregnancy are dynamic and precisely regulated, playing a crucial role in pregnancy and related dysfunctions. In this study, we conducted a metabolomic analysis of 37 blood samples collected from pandas in estrus, acyclic, and potential pregnant states, employing rigorous screening to minimize the influence of diet. Our findings suggest that a reduced appetite can serve as an indicator for evaluating implantation time, representing a characteristic response to pregnancy and aiding in the prediction of delivery time in pregnant pandas. Metabolomic results indicate great metabolism variation from estrus to pregnancy, highlighting the association between amino acid metabolism and pregnancy outcomes. Compared to other pandas, individuals who successfully bred exhibit significantly elevated levels of arginine and histidine, even 2 months before experiencing a reduced appetite. Furthermore, the lipid profile undergoes distinct dynamic changes only in estrus samples. In summary, our study comprehensively characterizes the metabolism of giant pandas during gestation and proposes arginine and histidine as potential novel biomarkers for detecting the pregnancy state of giant pandas. [ABSTRACT FROM AUTHOR]

Soil microbial extracellular enzymes play crucial roles in soil carbon and nutrient cycling by catalyzing soil biochemical processes. However, the activity and stoichiometry of enzymes involved in the carbon, nitrogen, and phosphorus cycles in the environment with the highest density of wild giant pandas on the southern slopes of the Qinling Mountains is unknown. We have established eight research areas at an elevation of 1090–2621 m. The β‐1,4‐glucosidase (BG), β‐1,4‐N‐acetylglucosaminidase (NAG), and acid phosphatase (APase) in soil samples were measured. We used redundancy analysis and structural equation model to evaluate the driving factors of metabolic restriction of soil microorganisms along the elevational gradient, and four models were used to cross‐evaluate the nutrient restriction status of soil microorganisms. The results showed that most soil physiochemical properties, soil microbial biomass, and microbial extracellular enzymes exhibited a hump‐shaped trend with increasing elevation. Elevation indirectly affected soil enzyme activity and stoichiometry by C, N, and P status. Microorganisms are limited by C at lower and higher elevations but limited by N at medium elevations. These results could help strengthen the conservation and management of the wild panda's natural habitat. [ABSTRACT FROM AUTHOR]

Vision plays a crucial role in the survival of animals, and the visual system has particularly selectively evolved in response to the visual environment, ecological niche, and species habitats in vertebrate species. To date, a horizontal streak of retinal ganglion cell (RGC) distribution pattern is observed across mammal species. Here, we report that the giant panda's vertically oriented visual streak, combined with current evidence of the animal's forward‐placed eyes, ocular structure, and retinal neural topographic distribution patterns, presents the emergence of a well‐adapted binocular visual system. Our results suggest that the giant panda may use a unique way to processing binocular visual information. Results of mathematical simulation are in favor of this hypothesis. The topographic distribution properties of RGCs reported here could be essential for understanding the visual adaptation and evolution of this living fossil. [ABSTRACT FROM AUTHOR]

Simple Summary: Individual quantity is the guarantee of the long-term survival of a population. Currently, approximately 70% of the 33 local populations of wild giant pandas (Aliuropoda melanoleuca) face the risk of extinction. We studied four typical populations, from Tangjiahe, Wanglang, Liziping, and Daxiangling, and attempted to translocate individuals from large populations to enhance the viability of small populations. Our results validated a classic conclusion that the introduction of individuals from Tangjiahe and Wanglang significantly improved the genetic diversity in Liziping and Daxiangling. To ensure the long-term survival of two small populations over the next 100 years, we have devised multiple specific strategies for individual introduction. Our research has certain value for the rejuvenation of small populations of giant pandas, and we hope to provide a reference for the protection of endangered animals such as giant pandas. Currently, nearly 70% of giant panda populations are facing survival challenges. The introduction of wild individuals can bring vitality to them. To explore this possibility, we hypothetically introduced giant pandas from Tangjiahe and Wanglang into Liziping and Daxiangling Nature Reserves. We collected feces from these areas and analyzed the genetic diversity and population viability before and after introduction using nine microsatellite loci. The results showed the genetic level and viability of the large populations were better than the small populations. We investigated the effects of time intervals (2a, 5a, and 10a; year: a) and gender combinations (female: F; male: M) on the rejuvenation of small populations. Finally, five introduction plans (1F/2a, 2F/5a, 1F1M/5a, 3F/10a, and 2F1M/10a) were obtained to make Liziping meet the long-term survival standard after 100 years, and six plans (1F/2a, 2F/5a, 1F1M/5a, 4F/10a, 3F1M/10a, and 2F2M/10a) were obtained in Daxiangling. The more females were introduced, the greater the impact on the large populations. After introducing individuals, the number of alleles and expected heterozygosity of the Liziping population are at least 6.667 and 0.688, and for the Daxiangling population, they are 7.111 and 0.734, respectively. Our study provides theoretical support for the translocation of giant pandas, a reference for the restoration of other endangered species worldwide. [ABSTRACT FROM AUTHOR]

Simple Summary: The dietary structure and gut microbiota of giant pandas play an important role in nutrient utilization. The relationship between age-related dietary changes, nutrient digestibility, and gut microbiota composition is not fully understood. According to this study, bamboo consumption dramatically decreases with age. Meanwhile, a notably higher amount of bamboo shoots are consumed by geriatric giant pandas (GGP), which may be an important source of nutrients for them as bamboo shoots have a strong positive correlation with the concentration of crude protein (CP) and specific amino acids. In addition, the digestibility of crude fiber (CF) and certain amino acids are significantly correlated with the abundance of specific bacterial genera, highlighting that an age-related shift in gut microbiota has an influence on nutrient utilization. Our study provides new insights into the further study on the mechanisms underlying the effects of certain gut microbiota on nutrient digestion. Proper feeding and nutrition are vital for maintaining the health of giant pandas (GPs), yet the impact of dietary changes and gut microbiota on their nutrient utilization remains unclear. To address these uncertainties, we investigated nutrient intake and apparent digestibility, as well as gut microbiota composition across different age groups of giant pandas: sub-adults (SGPs), adults (AGPs), and geriatrics (GGPs). Our findings revealed notable shifts in dietary patterns from SGPs to GGPs. As they aged, significantly more bamboo shoots and less bamboo were consumed. Consequently, GGPs showed significantly reduced crude fiber (CF) intake and digestibility, while crude protein (CP) did not alter significantly. In addition, 16S rRNA microbial sequencing results showed that unidentified_Enterobacteriaceae and Streptococcus were the dominant genera among all age groups. The relative abundance of the genus Enterococcus in GGPs was significantly higher than that in SGPs and AGPs (p < 0.05). Overall, our results indicated the importance of bamboo shoots as a major source of protein in GGPs' diet, which can effectively compensate for the certain nutritional loss caused by the reduction in bamboo intake. Age-related changes in bacterial abundance have an effect on specific nutrient apparent digestibility in the gut of GPs. The data presented in this study serve as a useful reference for nutritional management in different ages of GPs under healthy conditions. [ABSTRACT FROM AUTHOR]

Extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli (ESBL-EC) is regarded as one of the most important priority pathogens within the One Health interface. However, few studies have investigated the occurrence of ESBL-EC in giant pandas, along with their antibiotic-resistant characteristics and horizontal gene transfer abilities. In this study, we successfully identified 12 ESBL-EC strains (8.33%, 12/144) out of 144 E. coli strains which isolated from giant pandas. We further detected antibiotic resistance genes (ARGs), virulence-associated genes (VAGs) and mobile genetic elements (MGEs) among the 12 ESBL-EC strains, and the results showed that 13 ARGs and 11 VAGs were detected, of which blaCTX-M (100.00%, 12/12, with 5 variants observed) and papA (83.33%, 10/12) were the most prevalent, respectively. And ISEcp1 (66.67%, 8/12) and IS26 (66.67%, 8/12) were the predominant MGEs. Furthermore, horizontal gene transfer ability analysis of the 12 ESBL-EC showed that all blaCTX-M genes could be transferred by conjugative plasmids, indicating high horizontal gene transfer ability. In addition, ARGs of rmtB and sul2, VAGs of papA, fimC and ompT, MGEs of ISEcp1 and IS26 were all found to be co-transferred with blaCTX-M. Phylogenetic analysis clustered these ESBL-EC strains into group B2 (75.00%, 9/12), D (16.67%, 2/12), and B1 (8.33%, 1/12), and 10 sequence types (STs) were identified among 12 ESBL-EC (including ST48, ST127, ST206, ST354, ST648, ST1706, and four new STs). Our present study showed that ESBL-EC strains from captive giant pandas are reservoirs of ARGs, VAGs and MGEs that can co-transfer with blaCTX-M via plasmids. Transmissible ESBL-EC strains with high diversity of resistance and virulence elements are a potential threat to humans, animals and surrounding environment. [ABSTRACT FROM AUTHOR]

The role that visual discriminative ability plays among giant pandas in social communication and individual discrimination has received less attention than olfactory and auditory modalities. Here, we used an eye-tracker technology to investigate pupil fixation patterns for 8 captive male giant pandas Ailuropoda melanoleuca. We paired images (N =  26) of conspecifics against: 1) sympatric predators (gray wolves and tigers), and non-threatening sympatric species (golden pheasant, golden snub-nosed monkey, takin, and red panda), 2) conspecifics with atypical fur coloration (albino and brown), and 3) zookeepers/non-zookeepers wearing either work uniform or plain clothing. For each session, we tracked the panda's pupil movements and measured pupil first fixation point (FFP), fixation latency, total fixation count (TFC), and duration (TFD) of attention to each image. Overall, pandas exhibited similar attention (FFPs and TFCs) to images of predators and non-threatening sympatric species. Images of golden pheasant, snub-nosed monkey, and tiger received less attention (TFD) than images of conspecifics, whereas images of takin and red panda received more attention, suggesting a greater alertness to habitat or food competitors than to potential predators. Pandas' TFCs were greater for images of black-white conspecifics than for albino or brown phenotypes, implying that familiar color elicited more interest. Pandas reacted differently to images of men versus women. For images of women only, pandas gave more attention (TFC) to familiar combinations (uniformed zookeepers and plain-clothed non-zookeepers), consistent with the familiarity hypothesis. That pandas can use visual perception to discriminate intra-specifically and inter-specifically, including details of human appearance, has applications for panda conservation and captive husbandry. [ABSTRACT FROM AUTHOR]

Simple Summary: This study presents a new framework for understanding how tourists perceive animal welfare, incorporating insights from tourists, researchers, and the animals themselves. Using scientific theories to define key aspects of animal welfare, the framework is refined based on tourist feedback, making it a reliable tool for assessing these perceptions. At the Chengdu Research Base of Giant Panda Breeding, we analyzed 4839 visitor comments from March to August 2023 to evaluate perceptions of panda welfare. This method highlights the importance of clear communication in educational programs, aiming to boost public understanding of animal welfare. By addressing the diverse and complex views of tourists, the framework supports more effective conservation education. It shows that collaborative efforts can create a flexible and theoretically sound benchmarking system, enhancing tourist education and fostering a stronger commitment to animal welfare and conservation as essential elements of sustainable tourism. This study introduces a co-design benchmarking framework to understand tourists' perceptions of animal welfare, integrating diverse perspectives from tourists, researchers, and animals. By leveraging scientific theories to establish benchmark dimensions, the framework is refined through visitor input, ensuring a robust and adaptable methodological tool for assessing tourists' perceptions and animal informed consent in wildlife tourism. Using the Chengdu Research Base of Giant Panda Breeding as an example, we analyzed 4839 visitor comments collected from March to August 2023 to benchmark perceptions of giant panda welfare. This approach underscores the importance of effective communication in educational initiatives, aiming to enhance public literacy and knowledge about animal welfare. By addressing the complexity and variability in tourists' perceptions, the proposed framework contributes to more impactful conservation education efforts. The study demonstrates that a collaborative effort results in a benchmarking framework that is firmly grounded in theoretical foundations yet flexible enough to adapt based on visitors' insights and animal participation. Ultimately, this comprehensive approach ensures that educational initiatives resonate with tourists' diverse backgrounds, fostering a deeper understanding and commitment to animal welfare and conservation, which, we argue, should be key components of sustainable tourism. [ABSTRACT FROM AUTHOR]

Background: Babesia spp. are protozoan parasites that infect the red blood cells of domesticated animals, wildlife and humans. A few cases of giant pandas (a flagship species in terms of wildlife conservation) infected with a putative novel Babesia sp. have been reported. However, comprehensive research on the morphological and molecular taxonomic classification of this novel Babesia sp. is still lacking. This study was designed to close this gap and formally describe this new Babesia sp. infecting giant pandas. Methods: Detailed morphological, molecular and phylogenetic analyses were conducted to characterise this Babesia sp. and to assess its systematic relationships with other Babesia spp. Blood samples from giant pandas infected with Babesia were subjected to microscopic examination. The 18S ribosomal RNA (18S rRNA), cytochrome b (cytb) and mitochondrial genome (mitogenome) of the new Babesia sp. were amplified, sequenced and assembled using DNA purified from blood samples taken from infected giant pandas. Based on the newly generated 18S rRNA, cytb and mitogenome sequences, phylogenetic trees were constructed. Results: Morphologically, the Babesia sp. from giant pandas exhibited various forms, including round to oval ring-shaped morphologies, resembling those found in other small canine Babesia spp. and displaying typical tetrads. Phylogenetic analyses with the 18S rRNA, cytb and mitogenome sequences revealed that the new Babesia sp. forms a monophyletic group, with a close phylogenetic relationship with the Babesia spp. that infect bears (Ursidae), raccoons (Procyonidae) and canids (Canidae). Notably, the mitogenome structure consisted of six ribosomal large subunit-coding genes (LSU1-6) and three protein-coding genes (cytb, cox3 and cox1) arranged linearly. Conclusions: Based on coupled morphological and genetic analyses, we describe a novel species of the genus Babesia, namely, Babesia ailuropodae n. sp., which infects giant pandas. [ABSTRACT FROM AUTHOR]

As human activities continue to expand, wildlife persistence faces escalating threats from roads. In Wolong area of Giant Panda National Park, the local giant pandas (Ailuropoda melanoleuca) are divided into two population groups along the National Highway G350 (NHG). Therefore, selecting suitable areas to help those giant pandas communicate across the NHG is necessary. In this research, we evaluated the presence of human activities and simulated their absence to analyze how they affect the giant panda's habitat in Wolong. Subsequently, based on the kernel density estimation (KDE) for giant pandas and the main human distribution locations, we selected suitable areas for the population link between the two road sections on the NHG. We simulated the absence of human activities on the two road sections to compare changes in the habitat suitability index (HSI) and connectivity value (CV) relative to their presence. We aimed to carefully select the area for future giant panda corridor plans and simulate whether eliminating human activities will significantly improve the HSI and CV of the area. Our results show that: (1) Human activities presence has led to subtle changes in the landscape pattern of suitable habitats and a decrease in Wolong by 78.76 km2 compared to their absence. (2) Human activities presence significantly reduced HSI and CV in the 1000 m buffer along the NHG compared to their absence. (3) The HSI and CV of the 1000 m buffer in the simulated absence of human activities for the two road sections were significantly higher than their presence. This research identified the optimal road section for crossing the NHG to link giant panda population groups and habitats in Wolong. These insights are significant for formulating conservation decisions and corridor plans and for promoting wildlife conservation in reserves amid high levels of human activity. [ABSTRACT FROM AUTHOR]

Climate change has triggered a series of global problems, posing a huge threat to the distribution of many plants and animals, especially endangered species such as the giant panda. Therefore, predicting the distribution of habitat quality under climate change conditions is of great significance for protecting these species. In this study, we examined the correlation between suitable habitat index and ecosystem services using 260 occurrence records and 13 environmental factors with giant pandas as the model species. The species distribution models can also be employed to predict and compare the potential geographical distribution of giant pandas at present and in the 2050s and 2090s in the Qinling Mountains of Shaanxi Province. The results show the following: (1) The relationship between suitable habitat index and ecosystem services of giant panda is not uniform. (2) From 2040 to 2100, the existing habitats may decrease by 47.8% to 98.5%. (3) The main direction of change in the center of the distribution of the giant panda's habitat is to migrate first eastward and then northwestward. Our results regarding the potential distribution pattern of giant pandas in the Qinling Mountains and their response to climate change can provide important references for optimizing the conservation and habitat management of wild giant pandas in the Qinling Mountains. [ABSTRACT FROM AUTHOR]

Introduction: Microbial community composition is closely associated with host disease onset and progression, underscoring the importance of understanding host-microbiota dynamics in various health contexts. Methods: In this study, we utilized full-length 16S rRNA gene sequencing to conduct species-level identification of the microorganisms in the oral cavity of a giant panda (Ailuropoda melanoleuca) with oral malignant fibroma. Results: We observed a significant difference between the microbial community of the tumor side and non-tumor side of the oral cavity of the giant panda, with the latter exhibiting higher microbial diversity. The tumor side was dominated by specific microorganisms, such as Fusobacterium simiae, Porphyromonas sp. feline oral taxon 110, Campylobacter sp. feline oral taxon 100, and Neisseria sp. feline oral taxon 078, that have been reported to be associated with tumorigenic processes and periodontal diseases in other organisms. According to the linear discriminant analysis effect size analysis, more than 9 distinct biomarkers were obtained between the tumor side and non-tumor side samples. Furthermore, the Kyoto Encyclopedia of Genes and Genomes analysis revealed that the oral microbiota of the giant panda was significantly associated with genetic information processing and metabolism, particularly cofactor and vitamin, amino acid, and carbohydrate metabolism. Furthermore, a significant bacterial invasion of epithelial cells was predicted in the tumor side. Discussion: This study provides crucial insights into the association between oral microbiota and oral tumors in giant pandas and offers potential biomarkers that may guide future health assessments and preventive strategies for captive and aging giant pandas. [ABSTRACT FROM AUTHOR]

Epigenetic regulation plays an important role in the evolution of species adaptations, yet little information is available on the epigenetic mechanisms underlying the adaptive evolution of bamboo‐eating in both giant pandas (Ailuropoda melanoleuca) and red pandas (Ailurus fulgens). To investigate the potential contribution of epigenetic to the adaptive evolution of bamboo‐eating in giant and red pandas, we performed hepatic comparative transcriptome and methylome analyses between bamboo‐eating pandas and carnivorous polar bears (Ursus maritimus). We found that genes involved in carbohydrate, lipid, amino acid, and protein metabolism showed significant differences in methylation and expression levels between the two panda species and polar bears. Clustering analysis of gene expression revealed that giant pandas did not form a sister group with the more closely related polar bears, suggesting that the expression pattern of genes in livers of giant pandas and red pandas have evolved convergently driven by their similar diets. Compared to polar bears, some key genes involved in carbohydrate metabolism and biological oxidation and cholesterol synthesis showed hypomethylation and higher expression in giant and red pandas, while genes involved in fat digestion and absorption, fatty acid metabolism, lysine degradation, resistance to lipid peroxidation and detoxification showed hypermethylation and low expression. Our study elucidates the special nutrient utilization mechanism of giant pandas and red pandas and provides some insights into the molecular mechanism of their adaptive evolution of bamboo feeding. This has important implications for the breeding and conservation of giant pandas and red pandas. [ABSTRACT FROM AUTHOR]

Research on wildlife monitoring methods is a crucial tool for the conservation of rare wildlife in China. However, the fact that rare wildlife monitoring images in field scenes are easily affected by complex scene information, poorly illuminated, obscured, and blurred limits their use. This often results in unstable recognition and low accuracy levels. To address this issue, this paper proposes a novel wildlife identification model for rare animals in Giant Panda National Park (GPNP). We redesigned the C3 module of YOLOv5 using NAMAttention and the MemoryEfficientMish activation function to decrease the weight of field scene features. Additionally, we integrated the WIoU boundary loss function to mitigate the influence of low-quality images during training, resulting in the development of the NMW-YOLOv5 model. Our model achieved 97.3% for mAP50 and 83.3% for mAP50:95 in the LoTE-Animal dataset. When comparing the model with some classical YOLO models for the purpose of conducting comparison experiments, it surpasses the current best-performing model by 1.6% for mAP50:95, showcasing a high level of recognition accuracy. In the generalization ability test, the model has a low error rate for most rare wildlife species and is generally able to identify wildlife in the wild environment of the GPNP with greater accuracy. It has been demonstrated that NMW-YOLOv5 significantly enhances wildlife recognition accuracy in field environments by eliminating irrelevant features and extracting deep, effective features. Furthermore, it exhibits strong detection and recognition capabilities for rare wildlife in GPNP field environments. This could offer a new and effective tool for rare wildlife monitoring in GPNP. [ABSTRACT FROM AUTHOR]

Taking the Giant Panda National Park (Ya'an Area, Sichuan) as the research area, based on the current status of giant panda distribution points and comprehensive consideration of the impact of terrain, natural resources, climate, atmosphere, vegetation, and bamboo on giant panda distribution, a comprehensive evaluation index system for the living environment of giant pandas is constructed for evaluation, combined with on-site investigations, and the impact of abandoned mines on the distribution of giant pandas is judged, and finally an ecological restoration strategy for abandoned mines is obtained. The results are as follows: (1) priority should be given to restoration of abandoned mines in areas where the elevation, aspect, precipitation, and temperature are suitable for the survival of giant pandas. (2) During the restoration of the mine, a variety of bamboos, firs and shrubs with different flowering cycles are selected for mixed planting in the same area, within a controllable number of years, form a Closed evergreen needle-leaved forest (fc >0.4), and meet the NDVImax within the range of 0.8-1.0. (3) The pollution of the atmospheric environment by construction dust, vehicle exhaust, and asbestos mines will be prevented through manual intervention. (4) The slope should be trimmed within the range of 23-48° as much as possible, and the water source for giant pandas should be appropriately increased. This study provides an important basis for the restoration of abandoned mines in the Giant Panda National Park (Ya'an area, Sichuan), and will also provide a reference for the restoration of abandoned mines in other areas and the entire Giant Panda National Park. [ABSTRACT FROM AUTHOR]

The issue of poor sexual performance of some male giant pandas seriously impairs the growth and the genetic diversity of the captive population, yet there is still no clear understanding of the cause of the loss of this ability and its underlying mechanism. In this study, we analyzed the gut microbiota and its function in 72 fecal samples obtained from 20 captive male giant pandas, with an equal allocation between individuals capable and incapable of natural mating. Additionally, we investigated fecal hormone levels and behavioral differences between the two groups. A correlation analysis was then conducted among these factors to explore the influencing factors of their natural mating ability. The results showed significant differences in the composition of gut microbiota between the two groups of male pandas. The capable group had significantly higher abundance of Clostridium sensu stricto 1 (padjusted =.0021, GLMM), which was positively correlated with fatty acid degradation and two‐component system functions (Spearman, padjusted <.05). Additionally, the capable group showed higher gene abundance in gut microbiota function including purine and pyrimidine metabolism and galactose metabolism, as well as pathways related to biological processes such as ribosome and homologous recombination (DEseq2, padjusted <.05). We found no significant differences in fecal cortisol and testosterone levels between the two groups, and no difference was found in their behavior either. Our study provides a theoretical and practical basis for further studying the behavioral degradation mechanisms of giant pandas and other endangered mammal species. [ABSTRACT FROM AUTHOR]

Objective: Probiotics are beneficial to the intestinal barrier, but few studies have investigated probiotics from giant pandas. This study aims to explore the preventive effects of giant panda-derived Clostridium butyricum on dextran sodium sulfate (DSS)-induced colitis in mice. Methods: Clostridium butyricum was administered to mice 14 days before administering DSS treatment to induce enteritis. Results: Clostridium butyricum B14 could more effectively prevent colitis in mice than C. butyricum B13. C. butyricum B14 protected the mouse colon by decreasing the histology index and serum interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-a) levels, which improved intestinal inflammation-related symptoms. In addition, the treatment led to the regulation of the expression of Tifa, Igkv12-89, and Nr1d1, which in turn inhibited immune pathways. The expression of Muc4, Lama3, Cldn4, Cldn3, Ocln, Zo1, Zo2, and Snai is related the intestinal mucosal barrier. 16S sequencing shows that the C. butyricum B14 significantly increased the abundance of certain intestinal probiotics. Overall, C. butyricum B14 exerted a preventive effect on colitis in mice by inhibiting immune responses, enhancing the intestinal barrier and increasing the abundance of probiotic species. Thus, C. butyricum B14 administration helps regulate the balance of the intestinal microecology. It can suppress immune pathways and enhance barrier-protective proteins. [ABSTRACT FROM AUTHOR]

China announced the development of its first 5 national parks in 2021, the primary objective of which is to conserve the natural state and integrity of natural ecosystems. As such, ecosystem services and biodiversity levels are crucial assessment factors for the parks. For Giant Panda National Park (GPNP), we evaluated ecological sensitivity based on water and soil erosion and rocky desertification; ecosystem services based on headwater conservation, soil and water conservation, and biodiversity conservation; and presence of giant panda (Ailuropoda melanoleuca) and sympatric species (e.g., takin [Budorcas taxicolor], Asiatic black bear [Ursus thibetanus]) habitat suitability derived from niche modeling to identify the ecosystem status and assess ecological problems within the park. From our results, we proposed ecologically critical areas to target to meet the park's goals. The suitable habitat for pandas and sympatric species encompassed 62.98% of the park and occurred mainly in the Minshan Mountains. One quarter of the total area (25.67%) contained areas important for ecosystem services. Ecologically sensitive and extremely sensitive areas covered 88.78% of the park and were distributed mainly in Qionglaishan and Minshan Mountains. This coverage indicated that there was much habitat for pandas and sympatric species but that the ecosystems in GPNP are vulnerable. Therefore, ecologically critical areas encompassed all suitable habitats for all the species examined and areas important and extremely important to ecosystem service provision,ecologically sensitive and extremely sensitive areas, encompassed 15.17% of panda habitat, accounted for 16.37% of the GPNP area, and were distributed mainly in the Minshan Mountains. Our results indicated where conservation efforts should be focused in the park and that by identifying ecologically critical areas managers can provide targeted protection for wildlife habitat and ecosystems and effectively and efficiently protect the composite ecosystem. Additionally, our methods can be used to inform development of new national parks. [ABSTRACT FROM AUTHOR]

Livestock grazing and the collection of bamboo shoots are the main threats to giant panda (Ailuropoda melanoleuca) habitat in the Liangshan Mountains in China. It is important to clarify the effect of these disturbances to the giant panda to formulate targeted management policies. Based on species distribution models and daily activity models, we investigated the effects of livestock grazing and bamboo shoot collection on giant pandas from May 2021 to July 2022. Our results indicated the giant panda's suitable habitat in the reserve covered 51.83 km² (15.02% of the reserve area). Grazing and bamboo shoot collection led to losses of 19.08 km² and 7.68 km² of suitable habitat, respectively. Together, the 2 activities resulted in a loss of 28.35 km² of suitable habitat, which was more than half of the area of panda habitat. The areas of suitable habitat for giant pandas significantly overlapped with the areas affected by both disturbances. Giant pandas did not show significant differences in daily activity rhythms under a single disturbance, but the daily activity rhythms of giant pandas differed when we compared the area combining the 2 disturbances with the undisturbed area. Our study reveals that the anthropogenic disturbances in the reserve have varying effects on the suitable habitat range and daily activity rhythm of giant pandas and evidence of a synergistic effect. Therefore, when formulating relevant conservation policies, it is important to fully evaluate the extent and characteristics of anthropogenic disturbances in shaping the population distribution and habitat preferences of the giant panda and other wildlife to enhance the efficacy of conservation management practices. [ABSTRACT FROM AUTHOR]

Domestic dogs are currently recognized as being infected by 25 different canine papillomavirus (CPV) types classified into three genera. A short sequence from a novel CPV type was amplified, along with CPV1, from a papilloma (wart) from the mouth of a dog. The entire 7499 bp genome was amplified, and CPV26 contained putative coding regions that were predicted to produce four early proteins and two late ones. The ORF L1 showed less than 62% similarity for all previously sequenced CPV types but over 69% similarity to multiple Omegapapillomavirus types from a variety of Caniform species including the giant panda, Weddel seal, and polar bear. Phylogenetic analysis confirmed CPV26 clusters within the Omegapapillomavirus genus. Specific primers were used to investigate the presence of CPV26 DNA within a series of 37 canine proliferative lesions. CPV26 DNA was amplified from one lesion, a cutaneous papilloma that also contained CPV6. This is the first time a PV type within the Omegapapillomavirus genus has been detected in a non-domestic species and this provides evidence that the omegapapillomaviruses infected a common ancestor of, and then co-evolved with, the Caniform species. Whether CPV26 causes disease is uncertain, but the absence of an E7 protein may suggest low pathogenicity. [ABSTRACT FROM AUTHOR]

Canine distemper virus (CDV) can cause fatal infections in giant pandas. Vaccination is crucial to prevent CDV infection in giant pandas. In this study, two bacterium-like particle vaccines F3-GEM and H4-GEM displaying the trimeric F protein or tetrameric H protein of CDV were constructed based on the Gram-positive enhanced-matrix protein anchor (GEM-PA) surface display system. Electron microscopy and Western blot results revealed that the F or H protein was successfully anchored on the surface of GEM particles. Furthermore, one more bacterium-like particle vaccine F3 and H4-GEM was also designed, a mixture consisting of F3-GEM and H4-GEM at a ratio of 1:1. To evaluate the effect of the three vaccines, mice were immunized with F3-GEM, H4-GEM or F3 and H4-GEM. It was found that the level of IgG-specific antibodies and neutralizing antibodies in the F3 and H4-GEM group was higher than the other two groups. Additionally, F3 and H4-GEM also increased the secretion of Th1-related and Th2-related cytokines. Moreover, F3 and H4-GEM induce IgG and neutralizing antibodies' response in dogs. Conclusions: In summary, F3 and H4-GEM can provoke better immune responses to CDV in mice and dogs. The bacterium-like particle vaccine F3 and H4-GEM might be a potential vaccine candidate for giant pandas against CDV infection. [ABSTRACT FROM AUTHOR]

This study describes Impatiens yingjingensis X.Q. Song, B.N. Song & Biao Yang, sp. nov., a new species collected from the Yingjing area of the Giant Panda National Park. This new species is distributed at an altitude of 1400-2100 m, with a plant height of 30-130 cm. The flowers are purple-red or light purple red, with 3-9 flowers on each inflorescence and the dorsal auricle of the lateral united petals is thread-like and about 2 cm long, differing significantly from other species of Impatiens. Furthermore, molecular data, as well as micro-morphological evidence under SEM (of pollens), also support the establishment of the new species. [ABSTRACT FROM AUTHOR]

The giant panda (Ailuropoda melanoleuca) is one of the important species in worldwide animal conservation. Because it is essential to understand the disease of giant panda for conservation, histopathological analyses of tissues are important to understand the pathogenesis. However, monoclonal antibodies (mAbs) against giant panda-derived proteins are limited. Podoplanin (PDPN) is an essential marker of lung type I alveolar epithelial cells, kidney podocytes, and lymphatic endothelial cells. PDPN is also overexpressed in various human tumors, which are associated with poor prognosis. Here, an anti-giant panda PDPN (gpPDPN) mAb, PMab-314 (mouse IgG1, kappa) was established using the Cell-Based Immunization and Screening method. PMab-314 recognized N-terminal PA16-tagged gpPDPN-overexpressed Chinese hamster ovary-K1 cells (CHO/PA16-gpPDPN) in flow cytometry. The KD value of PMab-314 for CHO/PA16-gpPDPN was determined as 1.3 × 10−8 M. Furthermore, PMab-314 is useful for detecting gpPDPN in western blot analysis. These findings indicate that PMab-314 is a useful tool for the analyses of gpPDPN-expressed cells. [ABSTRACT FROM AUTHOR]

Bacteria and phages are two of the most abundant biological entities in the gut microbiome, and diet and host phylogeny are two of the most critical factors influencing the gut microbiome. A stable gut bacterial community plays a pivotal role in the host's physiological development and immune health. A phage is a virus that directly infects bacteria, and phages' close associations and interactions with bacteria are essential for maintaining the stability of the gut bacterial community and the entire microbial ecosystem. Here, we utilized 99 published metagenomic datasets from 38 mammalian species to investigate the relationship (diversity and composition) and potential interactions between gut bacterial and phage communities and the impact of diet and phylogeny on these communities. Our results highlight the co-evolutionary potential of bacterial–phage interactions within the mammalian gut. We observed a higher alpha diversity in gut bacteria than in phages and identified positive correlations between bacterial and phage compositions. Furthermore, our study revealed the significant influence of diet and phylogeny on mammalian gut bacterial and phage communities. We discovered that the impact of dietary factors on these communities was more pronounced than that of phylogenetic factors at the order level. In contrast, phylogenetic characteristics had a more substantial influence at the family level. The similar omnivorous dietary preference and closer phylogenetic relationship (family Ursidae) may contribute to the similarity of gut bacterial and phage communities between captive giant panda populations (GPCD and GPYA) and omnivorous animals (OC; including Sun bear, brown bear, and Asian black bear). This study employed co-occurrence microbial network analysis to reveal the potential interaction patterns between bacteria and phages. Compared to other mammalian groups (carnivores, herbivores, and omnivores), the gut bacterial and phage communities of bamboo-eating species (giant pandas and red pandas) exhibited a higher level of interaction. Additionally, keystone species and modular analysis showed the potential role of phages in driving and maintaining the interaction patterns between bacteria and phages in captive giant pandas. In sum, gaining a comprehensive understanding of the interaction between the gut microbiota and phages in mammals is of great significance, which is of great value in promoting healthy and sustainable mammals and may provide valuable insights into the conservation of wildlife populations, especially endangered animal species. [ABSTRACT FROM AUTHOR]

Land-use changes lead to habitat loss and fragmentation, which poses a further threat to the survival of species. Therefore, it is crucial to analyze how land-use change affects its habitat. 37 counties in Sichuan Province, China, where giant pandas are distributed, were selected as the subjects. Through analyzing land-use change, habitat suitability and connectivity characteristics over the past 20 years, and establishing a correlation between them, the impacts of land-use change on the habitat suitability and connectivity of giant pandas were explained. The results showed that from 2000 to 2020, the different land-use areas in the study area showed a pattern of change with an increase in forest area, built-up area and water area, and a decrease in grassland area and cropland area. There were significant differences in the characteristics of land-use dynamics changes among counties. Changes in land-use dynamics have a significant impact on the habitat suitability and connectivity of giant pandas, which is manifested in the fact that the conversion of forestland to grassland and grassland to cultivated land significantly reduces habitat suitability, while the conversion of grassland to forestland and cultivated to forestland significantly increases the connectivity of giant panda habitats. Changes in the habitat suitability index were significantly and positively correlated with the land-use dynamics index and the land-use degree index. Our findings emphasize the importance of balancing socio-economic development, land-use, and conservation efforts to maintain giant panda habitat. Therefore, the development of rational land-use patterns in future management is key to maximizing the comprehensive social, economic and ecological benefits.

Abstract As human activities continue to expand, wildlife persistence faces escalating threats from roads. In Wolong area of Giant Panda National Park, the local giant pandas (Ailuropoda melanoleuca) are divided into two population groups along the National Highway G350 (NHG). Therefore, selecting suitable areas to help those giant pandas communicate across the NHG is necessary. In this research, we evaluated the presence of human activities and simulated their absence to analyze how they affect the giant panda's habitat in Wolong. Subsequently, based on the kernel density estimation (KDE) for giant pandas and the main human distribution locations, we selected suitable areas for the population link between the two road sections on the NHG. We simulated the absence of human activities on the two road sections to compare changes in the habitat suitability index (HSI) and connectivity value (CV) relative to their presence. We aimed to carefully select the area for future giant panda corridor plans and simulate whether eliminating human activities will significantly improve the HSI and CV of the area. Our results show that: (1) Human activities presence has led to subtle changes in the landscape pattern of suitable habitats and a decrease in Wolong by 78.76 km2 compared to their absence. (2) Human activities presence significantly reduced HSI and CV in the 1000 m buffer along the NHG compared to their absence. (3) The HSI and CV of the 1000 m buffer in the simulated absence of human activities for the two road sections were significantly higher than their presence. This research identified the optimal road section for crossing the NHG to link giant panda population groups and habitats in Wolong. These insights are significant for formulating conservation decisions and corridor plans and for promoting wildlife conservation in reserves amid high levels of human activity.

Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL-EC) is regarded as one of the most important priority pathogens within the One Health interface. However, few studies have investigated the occurrence of ESBL-EC in giant pandas, along with their antibiotic-resistant characteristics and horizontal gene transfer abilities. In this study, we successfully identified 12 ESBL-EC strains (8.33%, 12/144) out of 144 E. coli strains which isolated from giant pandas. We further detected antibiotic resistance genes (ARGs), virulence-associated genes (VAGs) and mobile genetic elements (MGEs) among the 12 ESBL-EC strains, and the results showed that 13 ARGs and 11 VAGs were detected, of which blaCTX-M (100.00%, 12/12, with 5 variants observed) and papA (83.33%, 10/12) were the most prevalent, respectively. And ISEcp1 (66.67%, 8/12) and IS26 (66.67%, 8/12) were the predominant MGEs. Furthermore, horizontal gene transfer ability analysis of the 12 ESBL-EC showed that all blaCTX-M genes could be transferred by conjugative plasmids, indicating high horizontal gene transfer ability. In addition, ARGs of rmtB and sul2, VAGs of papA, fimC and ompT, MGEs of ISEcp1 and IS26 were all found to be co-transferred with blaCTX-M. Phylogenetic analysis clustered these ESBL-EC strains into group B2 (75.00%, 9/12), D (16.67%, 2/12), and B1 (8.33%, 1/12), and 10 sequence types (STs) were identified among 12 ESBL-EC (including ST48, ST127, ST206, ST354, ST648, ST1706, and four new STs). Our present study showed that ESBL-EC strains from captive giant pandas are reservoirs of ARGs, VAGs and MGEs that can co-transfer with blaCTX-M via plasmids. Transmissible ESBL-EC strains with high diversity of resistance and virulence elements are a potential threat to humans, animals and surrounding environment.

ABSTRACT Some lactic acid bacteria (LAB) can provide significant health benefits, which are critically important for the conservation of endangered animals, such as giant pandas. However, little is known about the diversity and culturability of LAB in the giant panda gut microbiota. To understand the roles of LAB in giant panda conservation, it is critical to culture bacterial strains of interest. In this study, we established a pipeline to culture bacterial strains using enrichment of target bacteria with different liquid media and growth conditions. Then, the strains were isolated in solid media to study their functions. Using 210 samples from the culture enrichment method and 138 culture-independent samples, we obtained 1120 amplicon sequencing variants (ASVs) belonging to Lactobacillales. Out of the 1120 ASVs, 812 ASVs from the culture enrichment approach were twofold more diverse than 336 ASVs from the culture-independent approach. Many ASVs of interest were not detected in the culture-independent approach. Using this pipeline, we isolated many relevant bacterial strains and established a giant panda gut bacteria strain collection that included strains with low-abundance in culture-independent samples and included most of the giant panda LAB described by other researchers. The strain collection consisted of 60 strains representing 35 species of 12 genera. Thus, our pipeline is powerful and provides guidance in culturing gut microbiota of interest in hosts such as the giant panda.IMPORTANCECultivation is necessary to screen strains to experimentally investigate microbial traits, and to confirm the activities of novel genes through functional characterization studies. In the long-term, such work can aid in the identification of potential health benefits conferred by bacteria and this could aid in the identification of bacterial candidate strains that can be applied as probiotics. In this study, we developed a pipeline with low-cost and user-friendly culture enrichment to reveal the diversity of LAB in giant pandas. We compared the difference between culture-independent and culture enrichment methods, screened strains of interest that produced high concentrations of short-chain fatty acids (SCFAs), and we investigated the catalog of virulence factors, antibiotic resistance, butyrate and lactate synthesis genes of the strains at a genomic level. This study will provide guidance for microbiota cultivation and a foundation for future research aiming to understand the functions of specific strains.

Zoos consistently implement codes of conduct in efforts to manage visitor behaviour. However, few studies have examined the use of the codes of conduct in zoos, even though they carry significant ethical implications regarding the relationship between humans and animals in society. This study provides an explorative investigation into the use of codes of conduct at the Chengdu Research Base of Giant Panda Breeding (Panda Base). Positioning the Panda Base as a place to negotiate the boundaries between humans and animals, this study surveyed visitors’ initial engagement with the Base’s code of conduct, their compliance with the code, and their assessment of the code. The findings point to a significant disparity between how visitors engage with and perceive the value of the code, which failed to prevent visitors from having close contact with animals at the Panda Base. We argue that Foucault’s philosophy on taboos in modern society can help us understand the ineffectiveness of the codes of conduct in zoos. However, Kant’s philosophy can orient human-animal interactions more ethically and provide an opportunity to consider the significance of codes of conduct in zoos. Suggestions for improving the effectiveness of codes of conduct at zoos are provided.

Abstract Background Behaviors in captive animals, including changes in appetite, activity level, and social interaction, are often seen as adaptive responses. However, these behaviors may become progressively maladaptive, leading to stress, anxiety, depression, and other negative reactions in animals. Results In this study, we investigated the whole-genome sequencing data of 39 giant panda individuals, including 11 in captivity and 28 in the wild. To eliminate the mountain range effect and focus on the factor of captivity only, we first performed a principal component analysis. We then enumerated the 21,474,180 combinations of wild giant pandas (11 chosen from 28) and calculated their distances from the 11 captive individuals. The 11 wild individuals with the closest distances were used for the subsequent analysis. The linkage disequilibrium (LD) patterns demonstrated that the population was almost eliminated. We identified 505 robust selected genomic regions harboring at least one SNP, and the absolute frequency difference was greater than 0.6 between the two populations. GO analysis revealed that genes in these regions were mainly involved in nerve-related pathways. Furthermore, we identified 22 GO terms for which the selection strength significantly differed between the two populations, and there were 10 nerve-related pathways among them. Genes in the differentially abundant regions were involved in nerve-related pathways, indicating that giant pandas in captivity underwent minor genomic selection. Additionally, we investigated the relationship between genetic variation and chromatin conformation structures. We found that nucleotide diversity (θπ) in the captive population was correlated with chromatin conformation structures, which included A/B compartments, topologically associated domains (TADs) and TAD-cliques. For each GO term, we then compared the expression level of genes regulated by the above four factors (AB index, TAD intactness, TAD clique and PEI) with the corresponding genomic background. The retained 10 GO terms were all coordinately regulated by the four factors, and three of them were associated with nerve-related pathways. Conclusions This study revealed that giant pandas in captivity undergo short-term adaptation in nerve-related pathways. Furthermore, it provides new insights into the molecular mechanism of gene expression regulation under short-term adaptation to environmental change.

Responses of diverse gut microbiota affect the host's nutrient metabolism and disease immunity. However, giant pandas (Ailuropoda melanoleuca) have a low diversity of gut microbiota, and the reasons for this low diversity and its impact are poorly understood. In this study, we aimed to investigate the effects of diet on the diversity of gut microbiota in giant pandas. To analyze the functional genes of the gut microbiota, we employed PICRUSt (phylogenetic investigation of communities by reconstruction of unobserved states), a computational method for predicting the functional composition of genomes. A multispecies comparison was conducted, involving 66 individuals from 34 species including giant panda. Our comparative analysis revealed that a high-fiber diet significantly reduced the diversity of gut microbiota in giant pandas. Furthermore, we observed that the metabolic function of giant pandas, particularly in terms of energy families and amino acid metabolism, was significantly lower than in other species. During the high-fiber diet, the gut microbiota of giant pandas exhibited a greater abundance of genes involved in carbohydrate metabolism, amino acid metabolism, and transport functions. These findings suggest that a high-fiber bamboo (Poaceae) diet is associated with lower diversity and altered metabolic function of gut microbiota in giant pandas. Therefore, the gut microbiota of giant pandas undergoes functional adaptive changes in response to the consumption of a high-fiber bamboo diet. [ABSTRACT FROM AUTHOR]

Although great efforts have been made over several decades, habitat fragmentation has continually threatened the survival of giant pandas. Here, we describe the habitat fragmentation problem and provide suggestions on how to address it as well as discussing the key issues worthy of consideration from previous giant panda protection efforts. [ABSTRACT FROM AUTHOR]

Brown-and-white giant pandas (hereafter brown pandas) are distinct coat color mutants found exclusively in the Qinling Mountains, Shaanxi, China. However, its genetic mechanism has remained unclear since their discovery in 1985. Here, we identified the genetic basis for this coat color variation using a combination of field ecological data, population genomic data, and a CRISPR--Cas9 knockout mouse model. We de novo assembled a long-read-based giant panda genome and resequenced the genomes of 35 giant pandas, including two brown pandas and two family trios associated with a brown panda. We identified a homozygous 25-bp deletion in the first exon of Bace2, a gene encoding amyloid precursor protein cleaving enzyme, as the most likely genetic basis for brown-and-white coat color. This deletion was further validated using PCR and Sanger sequencing of another 192 black giant pandas and CRISPR-Cas9 edited knockout mice. Our investigation revealed that this mutation reduced the number and size of melanosomes of the hairs in knockout mice and possibly in the brown panda, further leading to the hypopigmentation. These findings provide unique insights into the genetic basis of coat color variation in wild animals. [ABSTRACT FROM AUTHOR]

Wildlife tourism is one of the strongest-performing sectors in the global tourism market. While tourists' preferences for and affection towards animals are a cornerstone of the industry, a better understanding of how experiences, including animal–tourist encounters and visitation frequency, influence visitors' animal preferences is required. Through a comparison of preferences among first-time and repeat visitors of four species (giant panda "Ailuropoda melanoleuca", red panda "Ailurus fulgens", peafowl "Pavo cristatus", and swan "Cygnus"), both before and after animal encounters at the Chengdu Research Base of Giant Panda Breeding (Panda Base), the results show that different species elicit varied and, at times, contrasting tourist preferences. As a result, animal preferences in wildlife tourism can vary based on different stages of visitation. Highlighting this dynamic relationship between animal preferences and visitation experiences is further elucidated through consumer learning theory and lively capital. The outcomes of this study contribute to a deeper grasp of human–animal interactions and have broader implications for the development of conservation programs in captive wildlife venues. [ABSTRACT FROM AUTHOR]

Infant call structure should have evolved to elicit maximum maternal attention and investment. Neonates of giant pandas produce three types of vocalizations reported to be vitally important in the context of mother–infant communications. However, how cubs, 0–15 days old, communicate with their mothers to elicit maternal care remains unknown. We analyzed 12 different call parameters of 3475 squawks, 1355 squalls, and 491 croaks from 11 captive giant panda (Ailuropoda melanoleuca) neonates from age 0 to 15 days. In playback experiments, we also tested whether mothers could detect ultrasound. Our results show that neonates use broadband calls with ultrasonic frequencies up to 65 kHz to convey information about their physiological needs and to attract maternal care. In playback experiments, we tested if mothers reacted differently to broadband calls (BBC) than to artificially altered calls that included only frequencies <20 kHz (AUDC) or calls that included only frequencies >20 kHz (USC). Playback confirmed that, although adult females responded significantly less often to USC, BBC than to or AUDC, they could detect USC, BBC and generally made appropriate behavioral responses, indicating a potential benefit for neonates to utilize ultrasonic and broadband frequencies. Our findings provide a new insight into mother–infant communication in giant pandas and will be helpful for reducing the mortality of cubs, younger than 1 month old, in captivity. [ABSTRACT FROM AUTHOR]

A non-invasive, fast, and reliable method for sex identification of the giant panda (Ailuropoda melanoleuca) was developed by genotyping five SNPs located at the sex chromosome amelogenin (AMEL) paralogs. The giant panda's sex can be accurately distinguished by the homozygous or heterozygous SNP genotypes. Mass spectrometry assay and Sanger sequencing both successfully genotyped tissue and fresh fecal samples collected from known-sex giant pandas. Additionally, we simulated the conditions of wild fecal samples, which were naturally degraded for up to two weeks, and successfully genotyped these samples by mass spectrometry assay in parallel. These results suggest that this is a powerful method for sex determination in highly degraded and lower concentrated DNA samples. [ABSTRACT FROM AUTHOR]

Zoos consistently implement codes of conduct in efforts to manage visitor behaviour. However, few studies have examined the use of the codes of conduct in zoos, even though they carry significant ethical implications regarding the relationship between humans and animals in society. This study provides an explorative investigation into the use of codes of conduct at the Chengdu Research Base of Giant Panda Breeding (Panda Base). Positioning the Panda Base as a place to negotiate the boundaries between humans and animals, this study surveyed visitors' initial engagement with the Base's code of conduct, their compliance with the code, and their assessment of the code. The findings point to a significant disparity between how visitors engage with and perceive the value of the code, which failed to prevent visitors from having close contact with animals at the Panda Base. We argue that Foucault's philosophy on taboos in modern society can help us understand the ineffectiveness of the codes of conduct in zoos. However, Kant's philosophy can orient human-animal interactions more ethically and provide an opportunity to consider the significance of codes of conduct in zoos. Suggestions for improving the effectiveness of codes of conduct at zoos are provided. [ABSTRACT FROM AUTHOR]

The diets of the eight species of ursids range from carnivory (e.g., polar bears, Ursus maritimus) to insectivory (e.g., sloth bears, Melursus ursinus), omnivory (e.g., brown bears, U. arctos), and herbivory (e.g., giant pandas, Ailuropoda melanoleuca). Dietary energy availability ranges from the high-fat, highly digestible, calorically dense diet of polar bears (~ 6.4 kcal digestible energy/g fresh weight) to the high-fiber, poorly digestible, calorically restricted diet (~ 0.7) of giant pandas. Thus, ursids provide the opportunity to examine the extent to which dietary energy drives evolution of energy metabolism in a closely related group of animals. We measured the daily energy expenditure (DEE) of captive brown bears in a relatively large, zoo-type enclosure and compared those values to previously published results on captive brown bears, captive and free-ranging polar bears, and captive and free-ranging giant pandas. We found that all three species have similar mass-specific DEE when travel distances and energy intake are normalized even though their diets differ dramatically and phylogenetic lineages are separated by millions of years. For giant pandas, the ability to engage in low-cost stationary foraging relative to more wide-ranging bears likely provided the necessary energy savings to become bamboo specialists without greatly altering their metabolic rate. [ABSTRACT FROM AUTHOR]

Background: Behaviors in captive animals, including changes in appetite, activity level, and social interaction, are often seen as adaptive responses. However, these behaviors may become progressively maladaptive, leading to stress, anxiety, depression, and other negative reactions in animals. Results: In this study, we investigated the whole-genome sequencing data of 39 giant panda individuals, including 11 in captivity and 28 in the wild. To eliminate the mountain range effect and focus on the factor of captivity only, we first performed a principal component analysis. We then enumerated the 21,474,180 combinations of wild giant pandas (11 chosen from 28) and calculated their distances from the 11 captive individuals. The 11 wild individuals with the closest distances were used for the subsequent analysis. The linkage disequilibrium (LD) patterns demonstrated that the population was almost eliminated. We identified 505 robust selected genomic regions harboring at least one SNP, and the absolute frequency difference was greater than 0.6 between the two populations. GO analysis revealed that genes in these regions were mainly involved in nerve-related pathways. Furthermore, we identified 22 GO terms for which the selection strength significantly differed between the two populations, and there were 10 nerve-related pathways among them. Genes in the differentially abundant regions were involved in nerve-related pathways, indicating that giant pandas in captivity underwent minor genomic selection. Additionally, we investigated the relationship between genetic variation and chromatin conformation structures. We found that nucleotide diversity (θπ) in the captive population was correlated with chromatin conformation structures, which included A/B compartments, topologically associated domains (TADs) and TAD-cliques. For each GO term, we then compared the expression level of genes regulated by the above four factors (AB index, TAD intactness, TAD clique and PEI) with the corresponding genomic background. The retained 10 GO terms were all coordinately regulated by the four factors, and three of them were associated with nerve-related pathways. Conclusions: This study revealed that giant pandas in captivity undergo short-term adaptation in nerve-related pathways. Furthermore, it provides new insights into the molecular mechanism of gene expression regulation under short-term adaptation to environmental change. [ABSTRACT FROM AUTHOR]

Introduction: The giant panda (Ailuropoda melanoleuca) reproduction is of worldwide attention, and the vaginal microbiome is one of the most important factors affecting the reproductive rate of giant pandas. The aim of this study is to investigate the diversity of vaginal mycobiota structure, and potential pathogenic fungi in female giant pandas during estrus and non-estrus. Methods: This study combined with high-throughput sequencing and laboratory testing to compare the diversity of the vaginal mycobiota in giant pandas during estrus and non-estrus, and to investigate the presence of potentially pathogenic fungi. Potentially pathogenic fungi were studied in mice to explore their pathogenicity. Results and discussion: The results revealed that during estrus, the vaginal secretions of giant pandas play a crucial role in fungal colonization. Moreover, the diversity of the vaginal mycobiota is reduced and specificity is enhanced. The abundance of Trichosporon and Cutaneotrichosporon in the vaginal mycobiota of giant pandas during estrus was significantly higher than that during non-estrus periods. Apiotrichum and Cutaneotrichosporon were considered the most important genera, and they primarily originate from the environment owing to marking behavior exhibited during the estrous period of giant pandas. Trichosporon is considered a resident mycobiota of the vagina and is an important pathogen that causes infection when immune system is suppressed. Potentially pathogenic fungi were further isolated and identified from the vaginal secretions of giant pandas during estrus, and seven strains of Apiotrichum (A. brassicae), one strain of Cutaneotrichosporon (C. moniliiforme), and nine strains of Trichosporon (two strains of T. asteroides, one strain of T. inkin, one strain of T. insectorum, and five strains of T. japonicum) were identified. Pathogenicity results showed that T. asteroides was the most pathogenic strain, as it is associated with extensive connective tissue replacement and inflammatory cell infiltration in both liver and kidney tissues. The results of this study improve our understanding of the diversity of the vaginal fungi present in giant pandas and will significantly contribute to improving the reproductive health of giant pandas in the future. [ABSTRACT FROM AUTHOR]

Reintroduction programs seek to restore degraded populations and reverse biodiversity loss. To examine the hypothesis that gut symbionts could be used as an indicator of reintroduction success, we performed intensive metagenomic monitoring over 10 years to characterize the ecological succession and adaptive evolution of the gut symbionts of captive giant pandas reintroduced to the wild. We collected 63 fecal samples from 3 reintroduced individuals and 22 from 9 wild individuals and used 96 publicly available samples from another 3 captive individuals. By microbial composition analysis, we identified 3 community clusters of the gut microbiome (here termed enterotypes) with interenterotype succession that was closely related to the reintroduction process. Each of the 3 enterotypes was identified based on significant variation in the levels of 1 of 3 genera: Clostridium, Pseudomonas, and Escherichia. The enterotype of captive pandas was Escherichia. This enterotype was gradually replaced by the Clostridium enterotype during the wild‐training process, which in turn was replaced by the Pseudomonas enterotype that resembled the enterotype of wild pandas, an indicator of conversion to wildness and a successful reintroduction. We also isolated 1 strain of Pseudomonas protegens from the wild enterotype, a previously reported free‐living microbe, and found that its within‐host evolution contributed to host dietary adaptation in the wild. Monitoring gut microbial structure provides a novel, noninvasive tool that can be used as an indicator of successful reintroduction of a captive individual to the wild. [ABSTRACT FROM AUTHOR]