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Yan Z, Liu X, Liu H, Xu H, Liu Y, Li C, Wang B, Cui S, Jia T, Yang D, Zhang C, Liu X, Buesching CD, Liu D. Assessment of stress levels and reproductive condition in giant pandas: insights from hair, faecal and saliva samples. CONSERVATION PHYSIOLOGY 2024; 12:coae044. [PMID: 38962510 PMCID: PMC11221559 DOI: 10.1093/conphys/coae044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 05/29/2024] [Accepted: 06/14/2024] [Indexed: 07/05/2024]
Abstract
Concerted conservation efforts have brought the giant panda (Ailuropoda melanoleuca) back from the brink of extinction, but pandas continue to face anthropogenic threats in the wild and breeding success in captivity remains low. Because stress can have detrimental impacts on reproduction, monitoring stress- and sex-steroid levels would help assess the effectiveness of conservation mitigation measures in panda populations as well as monitor the welfare and reproductive health of captive animals. In this proof-of-concept study, we used faecal sex steroid and cortisol concentrations (n = 867 samples collected from five males and five females at Beijing Zoo every 4 days over the course of 12 months) as a reference to investigate if testosterone, estradiol, progesterone and cortisol can be meaningfully measured in panda hair (n = 10) using radio-immuno-assays. Additionally, we calculated the ratio of testosterone to cortisol (T:C ratio) for each male, which can provide a biomarker of stress and physical performance. Our findings revealed distinct monthly variations in faecal sex-steroid and cortisol concentrations, reflecting reproductive seasonality and visitor-related stress among individual pandas. Notably, the oldest male had a significantly lower T:C ratio than other males. Our results confirm that the level of sex steroids and cortisol can be assayed by panda hair, and the hair cortisol concentrations correlate significantly with that in faeces with one month lag behind (r = 0.68, P = 0.03). However, the concentrations of hormones detected in saliva are lower than those in faeces by two orders of magnitude, making it difficult to ensure accuracy. By assessing the applicability of hair, faecal and salivary sampling, we can infer their utility in monitoring the reproductive status and acute and chronic stress levels of giant pandas, thereby providing a means to gauge the success of ongoing habitat restoration efforts and to discuss the feasibility of sample collection from wild populations.
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Affiliation(s)
- Zheng Yan
- Key Laboratory for Biodiversity and Ecological Engineering of Ministry of Education, Department of Ecology, College of Life Sciences, Beijing Normal University, No.19, Xinjiekouwai Street, Haidian District, Beijing 100875, China
| | - Xiaoyan Liu
- Key Laboratory for Biodiversity and Ecological Engineering of Ministry of Education, Department of Ecology, College of Life Sciences, Beijing Normal University, No.19, Xinjiekouwai Street, Haidian District, Beijing 100875, China
| | - Haoqiu Liu
- Key Laboratory for Biodiversity and Ecological Engineering of Ministry of Education, Department of Ecology, College of Life Sciences, Beijing Normal University, No.19, Xinjiekouwai Street, Haidian District, Beijing 100875, China
| | - Haihong Xu
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, No.137, Xizhimenwai Street, Xicheng District, Beijing 100044, China
| | - Yanhui Liu
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, No.137, Xizhimenwai Street, Xicheng District, Beijing 100044, China
| | - Changqing Li
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, No.137, Xizhimenwai Street, Xicheng District, Beijing 100044, China
| | - Bo Wang
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, No.137, Xizhimenwai Street, Xicheng District, Beijing 100044, China
| | - Shengnan Cui
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, No.137, Xizhimenwai Street, Xicheng District, Beijing 100044, China
| | - Ting Jia
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, No.137, Xizhimenwai Street, Xicheng District, Beijing 100044, China
| | - Di Yang
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, No.137, Xizhimenwai Street, Xicheng District, Beijing 100044, China
| | - Chenglin Zhang
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, No.137, Xizhimenwai Street, Xicheng District, Beijing 100044, China
| | - Xuefeng Liu
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, No.137, Xizhimenwai Street, Xicheng District, Beijing 100044, China
| | - Christina D Buesching
- Department of Biology, Irving K. Barber Faculty of Sciences, The University of British Columbia, Okanagan, Kelowna, British Columbia V1V 1V7, Canada
| | - Dingzhen Liu
- Key Laboratory for Biodiversity and Ecological Engineering of Ministry of Education, Department of Ecology, College of Life Sciences, Beijing Normal University, No.19, Xinjiekouwai Street, Haidian District, Beijing 100875, China
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Yan Z, Lei Y, Zhao P, Zhang D, Shen J, Zhang G, Wei R, Liu H, Liu X, He Y, Shen S, Liu D. Natural mating ability is associated with gut microbiota composition and function in captive male giant pandas. Ecol Evol 2024; 14:e11189. [PMID: 38571808 PMCID: PMC10985376 DOI: 10.1002/ece3.11189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 03/05/2024] [Accepted: 03/12/2024] [Indexed: 04/05/2024] Open
Abstract
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 (p adjusted = .0021, GLMM), which was positively correlated with fatty acid degradation and two-component system functions (Spearman, p adjusted < .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, p adjusted < .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.
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Affiliation(s)
- Zheng Yan
- Department of Ecology, College of Life Sciences, Key Laboratory for Biodiversity and Ecological Engineering of Ministry of EducationBeijing Normal UniversityBeijingHebeiChina
| | - Yinghu Lei
- Research Center for the Qinling Giant PandaShaanxi Rare Wildlife Rescue BaseXi'anShaanxiChina
| | - Pengpeng Zhao
- Research Center for the Qinling Giant PandaShaanxi Rare Wildlife Rescue BaseXi'anShaanxiChina
| | - Danhui Zhang
- Research Center for the Qinling Giant PandaShaanxi Rare Wildlife Rescue BaseXi'anShaanxiChina
| | - Jiena Shen
- Research Center for the Qinling Giant PandaShaanxi Rare Wildlife Rescue BaseXi'anShaanxiChina
| | - Guiquan Zhang
- China Conservation and Research Centre for the Giant PandaWolongSichuanChina
| | - Rongping Wei
- China Conservation and Research Centre for the Giant PandaWolongSichuanChina
| | - Haoqiu Liu
- Department of Ecology, College of Life Sciences, Key Laboratory for Biodiversity and Ecological Engineering of Ministry of EducationBeijing Normal UniversityBeijingHebeiChina
| | - Xiaoyan Liu
- Department of Ecology, College of Life Sciences, Key Laboratory for Biodiversity and Ecological Engineering of Ministry of EducationBeijing Normal UniversityBeijingHebeiChina
| | - Yan He
- Department of Ecology, College of Life Sciences, Key Laboratory for Biodiversity and Ecological Engineering of Ministry of EducationBeijing Normal UniversityBeijingHebeiChina
| | - Sijia Shen
- Department of Ecology, College of Life Sciences, Key Laboratory for Biodiversity and Ecological Engineering of Ministry of EducationBeijing Normal UniversityBeijingHebeiChina
| | - Dingzhen Liu
- Department of Ecology, College of Life Sciences, Key Laboratory for Biodiversity and Ecological Engineering of Ministry of EducationBeijing Normal UniversityBeijingHebeiChina
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Babic NL, Johnstone CP, Reljić S, Sergiel A, Huber Đ, Reina RD. Evaluation of physiological stress in free-ranging bears: current knowledge and future directions. Biol Rev Camb Philos Soc 2023; 98:168-190. [PMID: 36176191 PMCID: PMC10086944 DOI: 10.1111/brv.12902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 08/25/2022] [Accepted: 08/31/2022] [Indexed: 01/12/2023]
Abstract
Stress responses, which are mediated by the neurogenic system (NS) and hypothalamic-pituitary-adrenal (HPA) axis help vertebrates maintain physiological homeostasis. Fight-or-flight responses are activated by the NS, which releases norepinephrine/noradrenaline and epinephrine/adrenaline in response to immediate stressors, whilst the HPA axis releases glucocorticoid hormones (e.g. cortisol and corticosterone) to help mitigate allostatic load. There have been many studies on stress responses of captive animals, but they are not truly reflective of typical ranges or the types of stressors encountered by free-ranging wildlife, such as responses and adaptation to environmental change, which are particularly important from a conservation perspective. As stress can influence the composition of age and sex classes of free-ranging populations both directly and indirectly, ecological research must be prioritised towards more vulnerable taxa. Generally, large predators tend to be particularly at risk of anthropogenically driven population declines because they exhibit reduced behavioural plasticity required to adapt to changing landscapes and exist in reduced geographic ranges, have small population sizes, low fecundity rates, large spatial requirements and occupy high trophic positions. As a keystone species with a long history of coexistence with humans in highly anthropogenic landscapes, there has been growing concern about how humans influence bear behaviour and physiology, via numerous short- and long-term stressors. In this review, we synthesise research on the stress response in free-ranging bear populations and evaluate the effectiveness and limitations of current methodology in measuring stress in bears to identify the most effective metrics for future research. Particularly, we integrate research that utilised haematological variables, cardiac monitors and Global Positioning System (GPS) collars, serum/plasma and faecal glucocorticoid concentrations, hair cortisol levels, and morphological metrics (primarily skulls) to investigate the stress response in ursids in both short- and long-term contexts. We found that in free-ranging bears, food availability and consumption have the greatest influence on individual stress, with mixed responses to anthropogenic influences. Effects of sex and age on stress are also mixed, likely attributable to inconsistent methods. We recommend that methodology across all stress indicators used in free-ranging bears should be standardised to improve interpretation of results and that a wider range of species should be incorporated in future studies.
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Affiliation(s)
- Natarsha L Babic
- School of Biological Sciences, Monash University, 25 Rainforest Walk, Clayton, 3800, Victoria, Australia
| | - Christopher P Johnstone
- School of Biological Sciences, Monash University, 25 Rainforest Walk, Clayton, 3800, Victoria, Australia
| | - Slaven Reljić
- Faculty of Veterinary Medicine, University of Zagreb, Heinzelova 55, Zagreb, 10000, Croatia
| | - Agnieszka Sergiel
- Institute of Nature Conservation, Polish Academy of Sciences, Adama Mickiewicza 33, Krakow, 31120, Poland
| | - Đuro Huber
- Faculty of Veterinary Medicine, University of Zagreb, Heinzelova 55, Zagreb, 10000, Croatia.,Institute of Nature Conservation, Polish Academy of Sciences, Adama Mickiewicza 33, Krakow, 31120, Poland
| | - Richard D Reina
- School of Biological Sciences, Monash University, 25 Rainforest Walk, Clayton, 3800, Victoria, Australia
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