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Zhu Y, Yang X, Tu Y, Wang B, Wang D, Shi Z, Indree T. Rodent disturbance reduces ecosystem stability through regulating plant and soil functions in Hulun Buir steppe. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 927:172206. [PMID: 38580124 DOI: 10.1016/j.scitotenv.2024.172206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 04/01/2024] [Accepted: 04/02/2024] [Indexed: 04/07/2024]
Abstract
Brandt's vole (Lasiopodomys brandtii), a typical rodent in the eastern Eurasian Steppe, has unclear impacts on ecosystem stability. In our field study in the Hulun Buir steppe, a multifunctional grazing ecosystem in this region, we used burrow entrance area and burrow density as alternative disturbance indices to derive a Disturbance Index (DI) for quantifying disturbance levels from rodents, and employed generalized linear mixed-effects model and the N-dimensional hypervolume framework to assess the influence of Brandt's vole disturbance on plant and soil functions, and then on the ecosystem functional stability. Our findings unequivocally illustrate that various plant functions including vegetation cover (Cover), aboveground biomass (ABG) and shoot carbon (ShootC) significantly declined with increasing disturbance, while shoot nitrogen (ShootN) and root nitrogen (RootN) show significantly positive responses. Soil functions such as soil nitrogen (SoilN), soil phosphorus (SoilP) and soil organic carbon (SoilC) showed significantly negative responses. Notably, the burrow entrance area exerts a more pronounced impact on both plant and soil functions in comparison to burrow density. Additionally, both disturbance indicators have a more significant influence on plant functions than on soil functions. Overall, the ecosystem functional stability progressively decreases with intensified disturbance, with varying response patterns for plant and soil functions, the former exhibited heightened stability as disturbance intensified, while the latter proved more stable at moderate disturbance levels. Our findings suggest that plant functions were more susceptible to disturbance by Brandt's vole compared to soils. Additionally, an ecosystem destabilization was synchronized with increasing Brandt's vole disturbance, although alterations in the functional stability of plants and soil show a different pattern.
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Affiliation(s)
- Yuanjun Zhu
- Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China; Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China
| | - Xiaohui Yang
- Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China; Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China
| | - Ya Tu
- Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China; Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China; School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China.
| | - Baizhu Wang
- Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China; Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China
| | - Danyu Wang
- Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China; Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China
| | - Zhongjie Shi
- Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China; Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China
| | - Tuvshintogtokh Indree
- Botanic Garden and Research Institute, Mongolian Academy of Sciences, Ulaanbaatar 13330, Mongolia
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Sugianto NA, Newman C, Macdonald DW, Buesching CD. Effects of weather and social factors on hormone levels in the European badger (Meles meles). ZOOLOGY 2023; 158:126093. [PMID: 37149943 DOI: 10.1016/j.zool.2023.126093] [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: 12/09/2022] [Revised: 03/31/2023] [Accepted: 04/27/2023] [Indexed: 05/09/2023]
Abstract
Animals in the wild continually experience changes in environmental and social conditions, which they respond to with behavioural, physiological and morphological adaptations related to individual phenotypic quality. During unfavourable environmental conditions, reproduction can be traded-off against self-maintenance, mediated through changes in reproductive hormone levels. Using the European badger (Meles meles) as a model species, we examine how testosterone in males and oestrogens in females respond to marked deviations in weather from the long-term mean (rainfall and temperature, where badger earthworm food supply is weather dependent), and to social factors (number of adult males and females per social group and total adults in the population), in relation to age, weight and head-body length. Across seasons, testosterone levels correlated postively with body weight and rainfall variability, whereas oestrone correlated positively with population density, but negatively with temperature variability. Restricting analyses to the mating season (spring), heavier males had higher testosterone levels and longer females had higher oestradiol levels. Spring oestrone levels were lower when temperatures were above normal. That we see these effects for this generally adaptive species with a broad bioclimatic niche serves to highlight that climatic effects (especially with the threat of anthropogenic climate change) on reproductive physiology warrant careful attention in a conservation context.
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Affiliation(s)
- N A Sugianto
- School of Biosciences, University of Birmingham, Birmingham, UK; Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, The Recanati-Kaplan Centre, Tubney OX13 5QL, UK.
| | - C Newman
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, The Recanati-Kaplan Centre, Tubney OX13 5QL, UK; Cook's Lake Farming Forestry and Wildlife Inc (Ecological Consultancy), Queens County, Nova Scotia, Canada
| | - D W Macdonald
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, The Recanati-Kaplan Centre, Tubney OX13 5QL, UK
| | - C D Buesching
- Cook's Lake Farming Forestry and Wildlife Inc (Ecological Consultancy), Queens County, Nova Scotia, Canada; Department of Biology, Irving K. Barber Faculty of Sciences, The University of British Columbia, Okanagan, Kelowna, British Columbia, Canada
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Fokidis HB, Brock T, Newman C, Macdonald DW, Buesching CD. Assessing chronic stress in wild mammals using claw-derived cortisol: a validation using European badgers ( Meles meles). CONSERVATION PHYSIOLOGY 2023; 11:coad024. [PMID: 37179707 PMCID: PMC10171820 DOI: 10.1093/conphys/coad024] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 01/26/2023] [Accepted: 05/02/2023] [Indexed: 05/15/2023]
Abstract
Measuring stress experienced by wild mammals is increasingly important in the context of human-induced rapid environmental change and initiatives to mitigate human-wildlife conflicts. Glucocorticoids (GC), such as cortisol, mediate responses by promoting physiological adjustments during environmental perturbations. Measuring cortisol is a popular technique; however, this often reveals only recent short-term stress such as that incurred by restraining the animal to sample blood, corrupting the veracity of this approach. Here we present a protocol using claw cortisol, compared with hair cortisol, as a long-term stress bio-indicator, which circumvents this constraint, where claw tissue archives the individual's GC concentration over preceding weeks. We then correlate our findings against detailed knowledge of European badger life history stressors. Based on a solid-phase extraction method, we assessed how claw cortisol concentrations related to season and badger sex, age and body-condition using a combination of generalized linear mixed models (GLMM) (n = 668 samples from 273 unique individuals) followed by finer scale mixed models for repeated measures (MMRM) (n = 152 re-captured individuals). Claw and hair cortisol assays achieved high accuracy, precision and repeatability, with similar sensitivity. The top GLMM model for claw cortisol included age, sex, season and the sex*season interaction. Overall, claw cortisol levels were significantly higher among males than females, but strongly influenced by season, where females had higher levels than males in autumn. The top fine scale MMRM model included sex, age and body condition, with claw cortisol significantly higher in males, older and thinner individuals. Hair cortisol was more variable than claw; nevertheless, there was a positive correlation after removing 34 outliers. We discuss strong support for these stress-related claw cortisol patterns from previous studies of badger biology. Given the potential of this technique, we conclude that it has broad application in conservation biology.
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Affiliation(s)
- H Bobby Fokidis
- Corresponding author: Department of Biology, Rollins College, Winter Park, Florida, USA.
| | - Taylor Brock
- Department of Biology, Rollins College, 1000 Holt Avenue, Winter Park, Florida, 32789-4499, USA
| | - Chris Newman
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, The Recanati-Kaplan Centre, Tubney House, Abindgon Rd, Tubney, OX13 5QL, UK
| | - David W Macdonald
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, The Recanati-Kaplan Centre, Tubney House, Abindgon Rd, Tubney, OX13 5QL, UK
| | - Christina D Buesching
- Irving K. Barber Faculty of Science, University of British Columbia, Okanagan campus, 3187 University Way, Kelowna, British Columbia, V1V1V7, Canada
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van Lieshout SHJ, Badás EP, Bright Ross JG, Bretman A, Newman C, Buesching CD, Burke T, Macdonald DW, Dugdale HL. Early-life seasonal, weather and social effects on telomere length in a wild mammal. Mol Ecol 2022; 31:5993-6007. [PMID: 34101279 DOI: 10.1111/mec.16014] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 06/03/2021] [Indexed: 01/31/2023]
Abstract
Early-life environmental conditions can provide a source of individual variation in life-history strategies and senescence patterns. Conditions experienced in early life can be quantified by measuring telomere length, which can act as a biomarker of survival probability in some species. Here, we investigate whether seasonal changes, weather conditions and group size are associated with early-life and/or early-adulthood telomere length in a wild population of European badgers (Meles meles). We found substantial intra-annual changes in telomere length during the first 3 years of life, where within-individual effects showed shorter telomere lengths in the winter following the first spring and a trend for longer telomere lengths in the second spring compared to the first winter. In terms of weather conditions, cubs born in warmer, wetter springs with low rainfall variability had longer early-life (3-12 months old) telomeres. Additionally, cubs born in groups with more cubs had marginally longer early-life telomeres, providing no evidence of resource constraint from cub competition. We also found that the positive association between early-life telomere length and cub survival probability remained when social and weather variables were included. Finally, after sexual maturity, in early adulthood (i.e., 12-36 months) we found no significant association between same-sex adult group size and telomere length (i.e., no effect of intrasexual competition). Overall, we show that controlling for seasonal effects, which are linked to food availability, is important in telomere length analyses, and that variation in telomere length in badgers reflects early-life conditions and also predicts first year cub survival.
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Affiliation(s)
- Sil H J van Lieshout
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK.,NERC Environmental Omics Visitor Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Elisa P Badás
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK.,Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Julius G Bright Ross
- Wildlife Conservation Research Unit, Department of Zoology, The Recanati-Kaplan Centre, University of Oxford, Abingdon, UK
| | - Amanda Bretman
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Chris Newman
- Wildlife Conservation Research Unit, Department of Zoology, The Recanati-Kaplan Centre, University of Oxford, Abingdon, UK
| | - Christina D Buesching
- Wildlife Conservation Research Unit, Department of Zoology, The Recanati-Kaplan Centre, University of Oxford, Abingdon, UK.,Department of Biology, The University of British Columbia, Okanagan, Kelowna, British Columbia, Canada
| | - Terry Burke
- NERC Environmental Omics Visitor Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - David W Macdonald
- Wildlife Conservation Research Unit, Department of Zoology, The Recanati-Kaplan Centre, University of Oxford, Abingdon, UK
| | - Hannah L Dugdale
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK.,Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
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Tsai MS, Newman C, Macdonald DW, Buesching CD. Adverse weather during in utero development is linked to higher rates of later-life herpesvirus reactivation in adult European badgers, Meles meles. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211749. [PMID: 35582658 PMCID: PMC9091846 DOI: 10.1098/rsos.211749] [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: 11/12/2021] [Accepted: 04/12/2022] [Indexed: 05/03/2023]
Abstract
Maternal immune and/or metabolic conditions relating to stress or nutritional status can affect in utero development among offspring with subsequent implications for later-life responses to infections. We used free-ranging European badgers as a host-pathogen model to investigate how prenatal weather conditions affect later-life herpesvirus genital tract reactivation. We applied a sliding window analysis of weather conditions to 164 samples collected in 2018 from 95 individuals born between 2005-2016. We test if the monthly mean and variation in rainfall and temperature experienced by their mother during the 12 months of delayed implantation and gestation prior to parturition subsequently affected individual herpes reactivation rates among these offspring. We identified four influential prenatal seasonal weather windows that corresponded with previously identified critical climatic conditions affecting badger survival, fecundity and body condition. These all occurred during the pre-implantation rather than the post-implantation period. We conclude that environmental cues during the in utero period of delayed implantation may result in changes that affect an individual's developmental programming against infection or viral reactivation later in life. This illustrates how prenatal adversity caused by environmental factors, such as climate change, can impact wildlife health and population dynamics-an interaction largely overlooked in wildlife management and conservation programmes.
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Affiliation(s)
- Ming-shan Tsai
- Department of Zoology, Wildlife Conservation Research Unit, University of Oxford, Recanati-Kaplan Centre, Abingdon Road, Tubney House, Tubney, Oxfordshire OX13 5QL, UK
| | - Chris Newman
- Department of Zoology, Wildlife Conservation Research Unit, University of Oxford, Recanati-Kaplan Centre, Abingdon Road, Tubney House, Tubney, Oxfordshire OX13 5QL, UK
- Cook's Lake Farming Forestry and Wildlife Inc (Ecological Consultancy), Queens County, Nova Scotia, Canada
| | - David W. Macdonald
- Department of Zoology, Wildlife Conservation Research Unit, University of Oxford, Recanati-Kaplan Centre, Abingdon Road, Tubney House, Tubney, Oxfordshire OX13 5QL, UK
| | - Christina D. Buesching
- Cook's Lake Farming Forestry and Wildlife Inc (Ecological Consultancy), Queens County, Nova Scotia, Canada
- Department of Biology, Irving K. Barber Faculty of Science, The University of British Columbia, Okanagan, Kelowna, British Columbia, Canada
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Soil δ 13C and δ 15N baselines clarify biogeographic heterogeneity in isotopic discrimination of European badgers (Meles meles). Sci Rep 2022; 12:200. [PMID: 34997035 PMCID: PMC8741785 DOI: 10.1038/s41598-021-04011-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 12/10/2021] [Indexed: 12/02/2022] Open
Abstract
Isotopic techniques have been used to study phenomena in the geological, environmental, and ecological sciences. For example, isotopic values of multiple elements elucidate the pathways energy and nutrients take in the environment. Isoscapes interpolate isotopic values across a geographical surface and are used to study environmental processes in space and time. Thus, isoscapes can reveal ecological shifts at local scales, and show distribution thresholds in the wider environment at the macro-scale. This study demonstrates a further application of isoscapes, using soil isoscapes of 13C/12C and 15N/14N as an environmental baseline, to understand variation in trophic ecology across a population of Eurasian badgers (Meles meles) at a regional scale. The use of soil isoscapes reduced error, and elevated the statistical signal, where aggregated badger hairs were used, and where individuals were identified using genetic microarray analysis. Stable isotope values were affected by land-use type, elevation, and meteorology. Badgers in lowland habitats had diets richer in protein and were adversely affected by poor weather conditions in all land classes. It is concluded that soil isoscapes are an effective way of reducing confounding biases in macroscale, isotopic studies. The method elucidated variation in the trophic and spatial ecology of economically important taxa at a landscape level. These results have implications for the management of badgers and other carnivores with omnivorous tendencies in heterogeneous landscapes.
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Wang S, Hou F. Burrow characteristics and ecological significance of Marmota himalayana in the northeastern Qinghai-Tibetan Plateau. Ecol Evol 2021; 11:9100-9109. [PMID: 34257946 PMCID: PMC8258228 DOI: 10.1002/ece3.7754] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 05/04/2021] [Accepted: 05/10/2021] [Indexed: 11/10/2022] Open
Abstract
Burrows provide burrowing animals with a place to hibernate, reproduce, and avoid predators and harsh weather conditions and thus have a vital impact on their survival. However, the general physical characteristics and ecological functions of Marmota himalayana burrows as well as whether there are differences in burrow traits under different terrains (e.g., sunny slopes, shady slopes, and flat areas) are not well understood. From July to August 2019 (warm season), we used unmanned aerial vehicles to fly at low altitudes and slow speeds to locate 131 M. himalayana burrows (45 on shaded slopes, 51 on sunny slopes, and 35 on flat areas) in the northeastern Qinghai-Tibetan Plateau region. We then measured the physical characteristics (burrow density, entrance size, first tunnel length, volume, orientation, and plant characteristics near the burrow entrance) of these burrows on site. We found that terrain had a substantial influence on burrow density, orientation, and entrance size and on the angle of the burrow entrance; species richness had a substantial impact on path density and tunnel volume. The physical parameters of the M. himalayana burrows showed that they function to protect the marmots from natural enemies and bad weather, provide good drainage, and maintain a stable microclimate around the entrance. We discuss the ability of burrowing animals (e.g., M. himalayana) to adapt to the external environment based on their burrow characteristics.
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Affiliation(s)
- Shu‐Lin Wang
- State Key Laboratory of Grassland Agro‐EcosystemsKey Laboratory of Grassland Livestock Industry InnovationMinistry of AgricultureLanzhouChina
- College of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhouChina
| | - Fu‐Jiang Hou
- State Key Laboratory of Grassland Agro‐EcosystemsKey Laboratory of Grassland Livestock Industry InnovationMinistry of AgricultureLanzhouChina
- College of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhouChina
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François L. Long-term monitoring of activities of badgers (Meles meles L.) in a broadleaved forest in France. EUR J WILDLIFE RES 2021. [DOI: 10.1007/s10344-020-01447-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Albery GF, Newman C, Ross JB, MacDonald DW, Bansal S, Buesching C. Negative density-dependent parasitism in a group-living carnivore. Proc Biol Sci 2020; 287:20202655. [PMID: 33323092 PMCID: PMC7779509 DOI: 10.1098/rspb.2020.2655] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 11/23/2020] [Indexed: 12/12/2022] Open
Abstract
Animals living at high population densities commonly experience greater exposure to disease, leading to increased parasite burdens. However, social animals can benefit immunologically and hygienically from cooperation, and individuals may alter their socio-spatial behaviour in response to infection, both of which could counteract density-related increases in exposure. Consequently, the costs and benefits of sociality for disease are often uncertain. Here, we use a long-term study of a wild European badger population (Meles meles) to investigate how within-population variation in host density determines infection with multiple parasites. Four out of five parasite taxa exhibited consistent spatial hotspots of infection, which peaked among badgers living in areas of low local population density. Combined movement, survival, spatial and social network analyses revealed that parasite avoidance was the likely cause of this negative density dependence, with possible roles for localized mortality, encounter-dilution effects, and micronutrient-enhanced immunity. These findings demonstrate that animals can organize their societies in space to minimize parasite infection, with important implications for badger behavioural ecology and for the control of badger-associated diseases.
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Affiliation(s)
| | - Chris Newman
- Wildlife Conservation Research Unit, The Recanati-Kaplan Centre, Department of Zoology, University of Oxford, Oxford, UK
| | - Julius Bright Ross
- Wildlife Conservation Research Unit, The Recanati-Kaplan Centre, Department of Zoology, University of Oxford, Oxford, UK
| | - David W. MacDonald
- Wildlife Conservation Research Unit, The Recanati-Kaplan Centre, Department of Zoology, University of Oxford, Oxford, UK
| | - Shweta Bansal
- Department of Biology, Georgetown University, Washington, DC, USA
| | - Christina Buesching
- Wildlife Conservation Research Unit, The Recanati-Kaplan Centre, Department of Zoology, University of Oxford, Oxford, UK
- Irving K. Barber Faculty of Sciences, Okanagan Department of Biology, The University of British Columbia, Kelowna, British Columbia, Canada
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Sugianto N, Newman C, Macdonald D, Buesching C. Extrinsic factors affecting cub development contribute to sexual size dimorphism in the European badger (Meles meles). ZOOLOGY 2019; 135:125688. [DOI: 10.1016/j.zool.2019.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 04/27/2019] [Accepted: 04/29/2019] [Indexed: 11/24/2022]
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