Giant panda foraging and movement patterns in response to bamboo shoot growth

Mapping multi-seasonal habitats of giant pandas to identify seasonal shifts

As a flagship species of biodiversity conservation globally, the giant panda has seasonal migration to cope with seasonal changes in available resources. Here, we have mapped the spatial distribution of multi-seasonal habitats of the giant panda across the Baishuijiang reserve in China. Results show that the spatial patterns are different in different seasons, generally, large patches are observed in the western part, while staggered clusters occur in the middle and eastern parts. That is, suitable habitats for giant pandas are mostly distributed in the west part. More than 75% of the predicted suitable habitats are within the core zone of the reserve year-round, indicating the core zone essentially meet giant panda's ecological needs, although this range could potentially be expanded. This study provides valuable insights into the spatiotemporal migration patterns of endangered species and helps to guide conservation planning.

Identifying priority protection areas of key food resources of the giant panda

Animals that live in seasonal environments adjust their reproduction cycle to optimize seasonal forage quality. Giant pandas ( Ailuropoda melanoleuca) are seasonal altitudinal migrants that feed on bamboo shoots and leaves with different nutritional quality. However, the importance of bamboo shoots to giant pandas, especially small and isolated populations, is not fully appreciated. Here, we explored whether mating time of giant pandas is shaped by bamboo shoot phenology. We also assessed the intensity of ongoing bamboo shoot harvesting by local communities in 42 giant panda reserves based on questionnaire surveys. Varying intensity and protection levels of bamboo shoot harvesting were found. From these data, we developed a priority ranking scheme of protection areas for this key food resource. Our study showed that pandas time their mating behavior to coincide with bamboo shoot phenology due to the high nutritional demands associated with mating and pregnancy. We also found that bamboo shoots were not well protected in many places. Liangshan, Daxiangling, and Xiaoxiangling, containing the most isolated panda populations, were identified as the areas with the most urgent need of protection. Furthermore, equal attention should be paid to the QiongL-B population, as this region holds considerable potential to serve as a corridor between the Minshan and Qionglai populations. To address the challenges posed by bamboo shoot harvesting, we recommend establishing more practical bamboo shoot management policies, increasing public awareness of bamboo shoot protection, and providing alternative sources of income for local communities.

Latitudinal and zoo specific zeitgebers influence circadian and circannual rhythmicity of behavior in captive giant pandas (Ailuropoda melanoleuca)

Introduction

The circadian clock influences many aspects of animal welfare including metabolism, breeding, and behavior. In most species, circadian clocks are internal clocks regulated by external environmental cues called zeitgebers. The most common zeitgebers are light/dark cycles, food, and temperature. However, within captive environments, animals can be housed at latitudes with different light/dark cycles than their natural habitat and most other zeitgebers are controlled by humans. The effects that modified zeitgebers have on captive animals' circadian and circannual rhythmicity is largely unknown. To explore this and potential welfare implications, we measured and analyzed observational behavioral data of zoo-housed giant pandas for one year utilizing live camera footage from six zoos across the world. The worldwide distribution of the zoos gives us the unique opportunity to investigate how housing giant pandas within and outside of their natural latitudinal range can affect circadian rhythmicity and behavior.

Methods

Focal sampling was completed for 11 giant pandas each month for 12 consecutive months to gain an estimate of one circannual cycle. Within each month, we estimated one daylight or 24 h cycle of activity/behavior by conducting 10-min observation sessions systemically each hour the pandas were visible.

Results

Zero-inflated negative binomial mixture models found that latitude is associated with activity levels, with pandas housed outside of their natural latitudinal range displaying less activity than those within their latitudinal range. Amount of daylight, temperature minimum, and temperature range were also associated with activity cycles, potentially acting as zeitgebers. An association between sexual-related and stereotypic behavioral cycles was found, with the circannual cycles fluctuating in synchrony throughout several points in a year.

Discussion

These results indicate that changes to common zeitgebers and environmental conditions can influence circadian and circannual cycles. The widespread evolution of circadian rhythms suggests an adaptive advantage to possessing one in an environment with cyclical changes, allowing species to anticipate changes in their environment and respond accordingly. Therefore, although animals are highly adaptive, creating a captive environment that mimics the environmental conditions for which the animal has evolved can encourage naturalistic cycles that ultimately aid in promoting positive welfare states and increasing chances of successful breeding and conservation.

Understanding Circadian and Circannual Behavioral Cycles of Captive Giant Pandas (Ailuropoda melanoleuca) Can Help to Promote Good Welfare

Circadian and circannual cycles of behavior regulate many aspects of welfare including metabolism, breeding, and behavioral interactions. In this study, we aim to demonstrate how systematically determining circadian and circannual cycles can provide insight into animals' needs and be part of an evidence-based approach to welfare assessment. We measured and analyzed the observational behavioral data of 13 zoo-housed giant pandas (Ailuropoda melanoleuca), across life stages and between sexes, each month for one year using live camera footage from six zoos across the world. Our results indicate that life stage was associated with changes in overall activity, feeding, locomotion, and pacing, and that sex influenced scent anointing and anogenital rubbing. Overall, the circadian rhythms showed three peaks of activity, including a nocturnal peak, as seen in wild giant pandas. We also found associations between sexual-related, stereotypical/abnormal, and feeding behavior, which are possibly linked to the timing of migration of wild pandas, and elucidated the relationship between a mother and cub, finding that they concentrate maternal behaviors to mainly after closing hours. Understanding these cycle patterns can aid animal care staff in predicting changing needs throughout the day, year, and life cycle and preemptively provide for those needs to best avoid welfare concerns.

Seasonal resource selection of an arboreal habitat specialist in a human-dominated landscape: a case study using red panda

Human dominated landscapes provide heterogeneous wildlife habitat. Conservation of habitat specialists, like red pandas Ailurus fulgens, inhabiting such landscapes is challenging. Therefore information on resource use across spatial and temporal scales could enable informed-decision making with better conservation outcomes. We aimed to examine the effect of geo-physical, vegetation, and disturbance variables on fine-scale habitat selection of red pandas in one such landscape. We equipped 10 red pandas with GPS collars in eastern Nepal in 2019 and monitored them for one year. Our analysis was based on a generalized-linear-mixed model. We found the combined effect of geo-physical, vegetation and disturbance variables resulted in differences in resource selection of red pandas and that the degree of response to these variables varied across seasons. Human disturbances, especially road and cattle herding activities, affected habitat utilization throughout the year whereas other variables were important only during restricted periods. For instance, geo-physical variables were influential in the premating and cub-rearing seasons while vegetation variables were important in all seasons other than premating. Red pandas selected steeper slopes with high solar insolation in the premating season while they occupied elevated areas and preferred specific aspects in the cub-rearing season. Furthermore, the utilized areas had tall bamboo in the birthing and cub-rearing seasons while they also preferred diverse tree species and high shrub cover in the latter. Our study demonstrates the significance of season-specific management, suggests the importance of specific types of vegetation during biologically crucial periods, and emphasizes the necessity to minimize disturbances throughout the year.

Succession of Intestinal Microbial Structure of Giant Pandas (Ailuropoda melanoleuca) during Different Developmental Stages and Its Correlation with Cellulase Activity

Simple Summary

Giant pandas (Ailuropoda melanoleuca) are endangered animals and are uniquely inhabitant in China. These rare animals have gradually developed bamboo-eating adaptability through persistent evolution. Intestinal microbes play an important role in the digestion, absorption, metabolism, and development of giant pandas especially by facilizing the degradation of bamboo polysaccharides such as cellulose. Currently, genes directly related to cellulose degradation have not been identified in the genome of giant panda, and cellulose digestion is therefore likely dependent on intestinal microbes. This study analyzed the changes in intestinal microbial structure of giant pandas (cubs, sub-adults, and adults) in different developmental stages. The impact was also assessed with the changes in food composition probed into the succession regularity of intestinal microbes and the activities of intestinal flora on the digestion and utilization of cellulose in bamboo.

Abstract

The interaction between intestinal microbial flora and giant pandas (Ailuropoda melanoleuca) is indispensable for the healthy development of giant pandas. In this study, we analysed the diversity of bacteria and fungi in the intestines of six giant pandas (two pandas in each development stage) with a high-throughput sequencing technique to expand the relative variation in abundance of dominant microbes and potential cellulose-degradation genera in the intestines of the giant pandas and to explore the correlation between dominant microbial genera in the intestines and cellulose digestion activities of giant pandas. The results showed that the intestinal bacterial diversity of young giant pandas was higher than that of sub-adult and adult giant pandas, and Shannon’s diversity index was about 2.0. The intestinal bacterial diversity of giant pandas from sub-adult to adult (mature stage) stage showed an increasing trend, but the intestinal fungal diversity showed no considerable regular relations with their ages. The microbial composition and abundance of giant pandas changed in different developmental stages. Pearson correlation analysis and path analysis showed that there was a close relationship between the dominant microbes in the intestines of giant pandas, and the interaction between microbial genera might affect the cellulose digestion ability of giant pandas. Generally, the digestibility of cellulose degraders in pandas was still insufficient, with low enzymic activity and immature microbial structure. Therefore, the utilization and digestion of bamboo cellulose still might not be a main source of energy for pandas.

Of pandas, fossils, and bamboo forests: ecological niche modeling of the giant panda (Ailuropoda melanoleuca) during the Last Glacial Maximum

The giant panda (Ailuropoda melanoleuca) is the most basal living species in the phylogeny of the family Ursidae, with a specialized diet composed of a variety of bamboo species. The evolutionary history and past distribution patterns of the giant panda remain poorly understood. Our aim was to integratively apply distinct methods to evaluate the evolutionary history and distributional patterns of the giant panda; these included phylogeography, ecological niche modeling (ENM), and fossil data. To this end, we characterized the panda’s past and present ecological niches and the environmental conditions that define them. To estimate the panda’s phylogeographic patterns and the environmental conditions (precipitation and temperature) available across its historical geographic range, we evaluated its past distribution during the Last Glacial Maximum (LGM). Considering that modeling biotic interactions (e.g., foraging, predation) is still an enormous challenge, we propose a novel modeling strategy based on the panda’s specialized diet, using an ensemble of three bamboo genera with distribution across the panda’s historical geographic range. Finally, we tested the accuracy of our approach by evaluating its ability to predict the LGM fossils. Our results support that the panda’s diversification across its distribution happened ca. 2.7 million years (Mya), coinciding with the likely period when the panda changed from a carnivorous to a vegetarian diet (from the Pleistocene to the Pliocene), acquiring its exclusively bamboo-feeding habits until the mid-Holocene. Our findings provide evidence of a historical directional niche change along which the panda has currently reached the lower limits of temperature and precipitation conditions existing on the geography where its food is available. Our proposed ENM based on the panda’s food habits accurately predicted 85.7% of the LGM fossils, in stark contrast with the traditional approach of modeling the distribution of species by using exclusively its own occurrences. These results provide insights on how to include Eltonian components to undertake more robust ENM when only abiotic variables are available. We emphasize the importance of integrating fossil information, whenever available, into the niche modeling process to include the historical component when estimating species ecological niches.

Amino Acid Nutrition for Optimum Growth, Development, Reproduction, and Health of Zoo Animals

Proteins are large polymers of amino acids (AAs) linked via peptide bonds, and major components for the growth and development of tissues in zoo animals (including mammals, birds, and fish). The proteinogenic AAs are alanine, arginine, aspartate, asparagine, cysteine, glutamate, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine. Except for glycine, they are all present in the L-isoform. Some carnivores may also need taurine (a nonproteinogenic AA) in their diet. Adequate dietary intakes of AAs are necessary for the growth, development, reproduction, health and longevity of zoo animals. Extensive research has established dietary nutrient requirements for humans, domestic livestock and companion animals. However, this is not true for many exotic or endangered species found in zoos due to the obstacles that accompany working with these species. Information on diets and nutrient profiles of free-ranging animals is needed. Even with adequate dietary intake of crude protein, dietary AAs may still be unbalanced, which can lead to nutrition-related diseases and disorders commonly observed in captive zoo species, such as dilated cardiomyopathy, urolithiasis, gut dysbiosis, and hormonal imbalances. There are differences in AA metabolism among carnivores, herbivores and omnivores. It is imperative to consider these idiosyncrasies when formulating diets based on established nutritional requirements of domestic species. With optimal health, populations of zoo animals will have a vastly greater chance of thriving in captivity. For endangered species especially, maintaining stable captive populations is crucial for conservation. Thus, adequate provision of AAs in diets plays a crucial role in the management, sustainability and expansion of healthy zoo animals.

Lactobacillus plantarum BSGP201683 Improves the Intestinal Barrier of Giant Panda Microbiota-Associated Mouse Infected by Enterotoxigenic Escherichia coli K88

Giant pandas often suffered from gastrointestinal disease, especially the captive sub-adult one. Our study aims to investigate whether L. plantarum G83, a good panda-derived probiotic, can improve the intestinal barrier against the enterotoxigenic Escherichia coli K88 (E. coli K88) infection in giant panda microbiota-associated mice (GPAM). We treated SPF mice with antibiotics cocktail and transplanted the giant panda intestinal microbiota to set up a GPAM. Our results demonstrated that the microbiota of GPAM changed over time and was relatively stable in the short-term experiment (2-4 weeks). Whereafter, the GPAM pretreated with L. plantarum G83 for 15 days and infected with enterotoxigenic E. coli K88. The result indicated that the number of Bifidobacteria spp. increased in GPAM-G and GPAM-GE groups; the Lactobacillus spp. only increased in the GPAM-G group. Although the abundance of Enterobacteriaceae spp. only decreased in the GPAM-G group, the copy number of Escherichia coli in the GPAM-E group was significantly lower than that in the other groups. Meanwhile, the L. plantarum G83-induced alteration of microbiota could increase the mRNA expression of Claudin-1, Zo-1, and Occludin-1 in the GPAM-G group in the ileum; only Occludin-1 was increased in the GPAM-GE group. The sIgA in the ileum showed a positive response, also the result of body weight and histology in both the GPAM-G and GPAM-GE group. These results indicated that the L. plantarum G83 could improve the intestinal barrier to defense the enterotoxigenic E. coli K88 invasion.