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Dickinson ER, Nwafor-Okoli C, Checkley SL, Elkin B, Branigan M, Serrano E, Kutz SJ. Direct and indirect costs of parasitism preceding a population decline of an Arctic ungulate. Sci Rep 2024; 14:17133. [PMID: 39054352 PMCID: PMC11272786 DOI: 10.1038/s41598-024-67904-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 07/17/2024] [Indexed: 07/27/2024] Open
Abstract
Parasites negatively affect the fitness of ungulate hosts directly, and in wild ungulates, these effects may be synzootic with other stressors, such as limited nutritional resources. In the Arctic, muskoxen (Ovibos moschatus) occur in a highly seasonal environment and must rely on finite energetic resources for survival and productivity. We investigated the costs of gastrointestinal nematodes on the body condition and reproductive status of 141 muskoxen, on Banks Island, Canada, when the population was at a peak in numbers and density. Using a Partial Least Squares Path Modelling approach, we found that high adult nematode abundance was associated with lower body condition, and high parasite abundance was associated with female reproduction including the indirect effect through on body condition (n = 87). These findings suggest that individuals prioritize energetic reserves for reproduction over parasite defence. In fall 2003, a severe icing event that restricted access to forage was associated with high overwinter mortality of muskoxen and a population crash. Through direct and indirect costs of parasite infection on body condition and reproduction, the high abundance of parasites may have contributed to the effects of this extreme weather event. Understanding the mechanisms in which parasites impact fitness can help explain the ecological drivers of ungulate populations and predict the interactions between the environment and populations.
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Affiliation(s)
- Eleanor R Dickinson
- Faculty of Veterinary Medicine, University of Calgary, 3280 University Drive, NW, Calgary, AB, T2N 1N4, Canada.
| | - Chinyere Nwafor-Okoli
- Faculty of Veterinary Medicine, University of Calgary, 3280 University Drive, NW, Calgary, AB, T2N 1N4, Canada
| | - Sylvia L Checkley
- Faculty of Veterinary Medicine, University of Calgary, 3280 University Drive, NW, Calgary, AB, T2N 1N4, Canada
| | - Brett Elkin
- Environment and Natural Resources, Government of the Northwest Territories, Yellowknife, NT, X1A 1Y3, Canada
| | - Marsha Branigan
- Environment and Natural Resources, Government of the Northwest Territories, Inuvik, NT, X0E 0T0, Canada
| | - Emmanuel Serrano
- Wildlife Ecology & Health Group (WE&H), Servei d'Ecopatologia de Fauna Salvatge (SEFaS), Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Susan J Kutz
- Faculty of Veterinary Medicine, University of Calgary, 3280 University Drive, NW, Calgary, AB, T2N 1N4, Canada
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van Beest FM, Schmidt NM, Stewart L, Hansen LH, Michelsen A, Mosbacher JB, Gilbert H, Le Roux G, Hansson SV. Geochemical landscapes as drivers of wildlife reproductive success: Insights from a high-Arctic ecosystem. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166567. [PMID: 37633375 DOI: 10.1016/j.scitotenv.2023.166567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/03/2023] [Accepted: 08/23/2023] [Indexed: 08/28/2023]
Abstract
The bioavailability of essential and non-essential elements in vegetation is expected to influence the performance of free-ranging terrestrial herbivores. However, attempts to relate the use of geochemical landscapes by animal populations directly to reproductive output are currently lacking. Here we measured concentrations of 14 essential and non-essential elements in soil and vegetation samples collected in the Zackenberg valley, northeast Greenland, and linked these to environmental conditions to spatially predict and map geochemical landscapes. We then used long-term (1996-2021) survey data of muskoxen (Ovibos moschatus) to quantify annual variation in the relative use of essential and non-essential elements in vegetated sites and their relationship to calf recruitment the following year. Results showed that the relative use of the geochemical landscape by muskoxen varied substantially between years and differed among elements. Selection for vegetated sites with higher levels of the essential elements N, Cu, Se, and Mo was positively linked to annual calf recruitment. In contrast, selection for vegetated sites with higher concentrations of the non-essential elements As and Pb was negatively correlated to annual calf recruitment. Based on the concentrations measured in our study, we found no apparent associations between annual calf recruitment and levels of C, Mn, Co, Zn, Cd, Ba, Hg, and C:N ratio in the vegetation. We conclude that the spatial distribution and access to essential and non-essential elements are important drivers of reproductive output in muskoxen, which may also apply to other wildlife populations. The value of geochemical landscapes to assess habitat-performance relationships is likely to increase under future environmental change.
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Affiliation(s)
- Floris M van Beest
- Department of Ecoscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark; Arctic Research Centre, Aarhus University, Ole Worms Allé 1, 8000 Aarhus C, Denmark.
| | - Niels Martin Schmidt
- Department of Ecoscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark; Arctic Research Centre, Aarhus University, Ole Worms Allé 1, 8000 Aarhus C, Denmark
| | - Lærke Stewart
- Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, Gullbringvegen 36, 3800 Bø, Norway
| | - Lars H Hansen
- Department of Ecoscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark; Arctic Research Centre, Aarhus University, Ole Worms Allé 1, 8000 Aarhus C, Denmark
| | - Anders Michelsen
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | | | - Hugo Gilbert
- Laboratoire Ecologie Fonctionnelle et Environnement (UMR- 5245), CNRS, Université de Toulouse, Avenue de l'Agrobiopole, 31326 Castanet Tolosan, France
| | - Gaël Le Roux
- Laboratoire Ecologie Fonctionnelle et Environnement (UMR- 5245), CNRS, Université de Toulouse, Avenue de l'Agrobiopole, 31326 Castanet Tolosan, France
| | - Sophia V Hansson
- Department of Ecoscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark; Laboratoire Ecologie Fonctionnelle et Environnement (UMR- 5245), CNRS, Université de Toulouse, Avenue de l'Agrobiopole, 31326 Castanet Tolosan, France
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3
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Schmidt NM, Michelsen A, Hansen LH, Aggerbeck MR, Stelvig M, Kutz S, Mosbacher JB. Sequential analysis of δ 15 N in guard hair suggests late gestation is the most critical period for muskox calf recruitment. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2023; 37:e9470. [PMID: 36601893 PMCID: PMC10078194 DOI: 10.1002/rcm.9470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 01/02/2023] [Accepted: 01/02/2023] [Indexed: 06/17/2023]
Abstract
RATIONALE Analysis of stable isotopes in tissue and excreta may provide information about animal diets and their nutritional state. As body condition may have a major influence on reproduction, linking stable isotope values to animal demographic rates may help unravel the drivers behind animal population dynamics. METHODS We performed sequential analysis of δ15 N values in guard hair from 21 muskoxen (Ovibos moschatus) from Zackenberg in high arctic Greenland. We were able to reconstruct the dietary history for the population over a 5-year period with contrasting environmental conditions. We examined the linkage between guard hair δ15 N values in 12 three-month periods and muskox calf recruitment to detect critical periods for muskox reproduction. Finally, we conducted similar analyses of the correlation between environmental conditions (snow depth and air temperature) and calf recruitment. RESULTS δ15 N values exhibited a clear seasonal pattern with high levels in summer and low levels in winter. However, large inter-annual variation was found in winter values, suggesting varying levels of catabolism depending on snow conditions. In particular δ15 N values during January-March were linked to muskox recruitment rates, with higher values coinciding with lower calf recruitment. δ15 N values were a better predictor of muskox recruitment rates than environmental conditions. CONCLUSIONS Although environmental conditions may ultimately determine the dietary δ15 N signal in muskox guard hairs, muskox calf recruitment was more strongly correlated with δ15 N values than ambient snow and temperature. The period January-March, corresponding to late gestation, appears particularly critical for muskox reproduction.
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Affiliation(s)
- Niels Martin Schmidt
- Department of Ecoscience and Arctic Research CentreAarhus UniversityRoskildeDenmark
| | - Anders Michelsen
- Department of BiologyUniversity of CopenhagenCopenhagen ØDenmark
- Center for PermafrostUniversity of CopenhagenCopenhagen KDenmark
| | - Lars Holst Hansen
- Department of Ecoscience and Arctic Research CentreAarhus UniversityRoskildeDenmark
| | | | | | - Susan Kutz
- Department of Ecosystem and Public Health, Faculty of Veterinary MedicineUniversity of CalgaryCalgaryABCanada
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Bawa SA, Gregg PC, Del Soccoro AP, Miller C, Andrew NR. Estimating the differences in critical thermal maximum and metabolic rate of Helicoverpa punctigera (Wallengren) (Lepidoptera: Noctuidae) across life stages. PeerJ 2021; 9:e12479. [PMID: 34820201 PMCID: PMC8605760 DOI: 10.7717/peerj.12479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 10/21/2021] [Indexed: 11/22/2022] Open
Abstract
Temperature is a crucial driver of insect activity and physiological processes throughout their life-history, and heat stress may impact life stages (larvae, pupae and adult) in different ways. Using thermolimit respirometry, we assessed the critical thermal maxima (CTmax-temperature at which an organism loses neuromuscular control), CO2 emission rate (V́CO2) and Q10 (a measure of V́CO2 temperature sensitivity) of three different life stages of Helicoverpa punctigera (Wallengren) by increasing their temperature exposure from 25 °C to 55 °C at a rate of 0.25 °C min−1. We found that the CTmax of larvae (49.1 °C ± 0.3 °C) was higher than pupae (47.4 °C ± 0.2 °C) and adults (46.9 °C ± 0.2 °C). The mean mass-specific CO2 emission rate (ml V́CO2 h−1) of larvae (0.26 ± 0.03 ml V́CO2 h−1) was also higher than adults (0.24 ± 0.04 ml V́CO2 h−1) and pupae (0.06 ± 0.02 ml V́CO2 h−1). The Q10: 25–35 °C for adults (2.01 ± 0.22) was significantly higher compared to larvae (1.40 ± 0.06) and Q10: 35–45 °C for adults (3.42 ± 0.24) was significantly higher compared to larvae (1.95 ± 0.08) and pupae (1.42 ± 0.98) respectively. We have established the upper thermal tolerance of H. punctigera, which will lead to a better understanding of the thermal physiology of this species both in its native range, and as a pest species in agricultural systems.
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Affiliation(s)
- Samuel A Bawa
- Zoology, Insect Ecology Laboratory, University of New England, Armidale, NSW, Australia.,Asuansi Agric. Station, Cape Coast, Central Region, Ghana
| | - Peter C Gregg
- Agronomy and Soil Science, University of New England, Armidale, NSW, Australia
| | - Alice P Del Soccoro
- Agronomy and Soil Science, University of New England, Armidale, NSW, Australia
| | - Cara Miller
- Science and Technology, University of New England, Armidale, NSW, Australia
| | - Nigel R Andrew
- Zoology, Insect Ecology Laboratory, University of New England, Armidale, NSW, Australia
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5
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Lavaud R, Filgueira R, Augustine S. The role of Dynamic Energy Budgets in conservation physiology. CONSERVATION PHYSIOLOGY 2021; 9:coab083. [PMID: 34707875 PMCID: PMC8545044 DOI: 10.1093/conphys/coab083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 08/31/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
The contribution of knowledge, concepts and perspectives from physiological ecology to conservation decision-making has become critical for understanding and acting upon threats to the persistence of sensitive species. Here we review applications of dynamic energy budget (DEB) theory to conservation issues and discuss how this theory for metabolic organization of all life on earth (from bacteria to whales) is well equipped to support current and future investigations in conservation research. DEB theory was first invented in 1979 in an applied institution for environmental quality assessment and mitigation. The theory has since undergone extensive development and applications. An increasing number of studies using DEB modelling have provided valuable insights and predictions in areas that pertain to conservation such as species distribution, evolutionary biology, toxicological impacts and ecosystem management. We discuss why DEB theory, through its mechanistic nature, its universality and the wide range of outcomes it can provide represents a valuable tool to tackle some of the current and future challenges linked to maintaining biodiversity, ensuring species survival, ecotoxicology, setting water and soil quality standards and restoring ecosystem structure and functioning in a changing environment under the pressure of anthropogenic driven changes.
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Affiliation(s)
- Romain Lavaud
- School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA
| | - Ramón Filgueira
- Marine Affairs Program, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Starrlight Augustine
- Akvaplan-niva, Fram High North Research Centre for Climate and the Environment, Tromsø 9296, Norway
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6
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Trondrud LM, Pigeon G, Król E, Albon S, Evans AL, Arnold W, Hambly C, Irvine RJ, Ropstad E, Stien A, Veiberg V, Speakman JR, Loe LE. Fat storage influences fasting endurance more than body size in an ungulate. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13816] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- L. Monica Trondrud
- Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life Sciences Ås Norway
| | - Gabriel Pigeon
- Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life Sciences Ås Norway
- Département de Biologie Faculté des Sciences 2500 boul. de l'Université Sherbrooke Sherbrooke QC Canada
| | - Elżbieta Król
- School of Biological Sciences Institute of Biological and Environmental Sciences University of Aberdeen Aberdeen UK
| | | | - Alina L. Evans
- Department of Forestry and Wildlife Management Inland Norway University of Applied Sciences Elverum Norway
| | - Walter Arnold
- Department of Interdisciplinary Life Sciences Research Institute of Wildlife Ecology University of Veterinary Medicine Vienna Austria
| | - Catherine Hambly
- School of Biological Sciences Institute of Biological and Environmental Sciences University of Aberdeen Aberdeen UK
| | - R. Justin Irvine
- The James Hutton Institute Aberdeen UK
- Frankfurt Zoological Society Addis Ababa Ethiopia
| | - Erik Ropstad
- Faculty of Veterinary Science Norwegian University of Life Sciences Oslo Norway
| | - Audun Stien
- Department of Arctic and Marine Biology The Arctic University of Norway Tromsø Norway
| | | | - John R. Speakman
- School of Biological Sciences Institute of Biological and Environmental Sciences University of Aberdeen Aberdeen UK
- Center for Energy Metabolism and Reproduction Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen China
- CAS Center of Excellence in Animal Evolution and Genetics Kunming China
- State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing China
| | - Leif Egil Loe
- Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life Sciences Ås Norway
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7
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Gallagher CA, Chudzinska M, Larsen-Gray A, Pollock CJ, Sells SN, White PJC, Berger U. From theory to practice in pattern-oriented modelling: identifying and using empirical patterns in predictive models. Biol Rev Camb Philos Soc 2021; 96:1868-1888. [PMID: 33978325 DOI: 10.1111/brv.12729] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 04/14/2021] [Accepted: 04/16/2021] [Indexed: 01/21/2023]
Abstract
To robustly predict the effects of disturbance and ecosystem changes on species, it is necessary to produce structurally realistic models with high predictive power and flexibility. To ensure that these models reflect the natural conditions necessary for reliable prediction, models must be informed and tested using relevant empirical observations. Pattern-oriented modelling (POM) offers a systematic framework for employing empirical patterns throughout the modelling process and has been coupled with complex systems modelling, such as in agent-based models (ABMs). However, while the production of ABMs has been rising rapidly, the explicit use of POM has not increased. Challenges with identifying patterns and an absence of specific guidelines on how to implement empirical observations may limit the accessibility of POM and lead to the production of models which lack a systematic consideration of reality. This review serves to provide guidance on how to identify and apply patterns following a POM approach in ABMs (POM-ABMs), specifically addressing: where in the ecological hierarchy can we find patterns; what kinds of patterns are useful; how should simulations and observations be compared; and when in the modelling cycle are patterns used? The guidance and examples provided herein are intended to encourage the application of POM and inspire efficient identification and implementation of patterns for both new and experienced modellers alike. Additionally, by generalising patterns found especially useful for POM-ABM development, these guidelines provide practical help for the identification of data gaps and guide the collection of observations useful for the development and verification of predictive models. Improving the accessibility and explicitness of POM could facilitate the production of robust and structurally realistic models in the ecological community, contributing to the advancement of predictive ecology at large.
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Affiliation(s)
- Cara A Gallagher
- Department of Plant Ecology and Conservation Biology, University of Potsdam, Am Mühlenberg 3, Potsdam, 14469, Germany.,Department of Bioscience, Aarhus University, Frederiksborgvej 399, Roskilde, 4000
| | - Magda Chudzinska
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, KY16 9ST, U.K
| | - Angela Larsen-Gray
- Department of Integrative Biology, University of Wisconsin-Madison, 250 N. Mills St., Madison, WI, 53706, U.S.A
| | | | - Sarah N Sells
- Montana Cooperative Wildlife Research Unit, The University of Montana, 205 Natural Sciences, Missoula, MT, 59812, U.S.A
| | - Patrick J C White
- School of Applied Sciences, Edinburgh Napier University, 9 Sighthill Ct., Edinburgh, EH11 4BN, U.K
| | - Uta Berger
- Institute of Forest Growth and Computer Science, Technische Universität Dresden, Dresden, 01062, Germany
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8
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Desforges JP, Marques GM, Beumer LT, Chimienti M, Hansen LH, Pedersen SH, Schmidt NM, van Beest FM. Environment and physiology shape Arctic ungulate population dynamics. GLOBAL CHANGE BIOLOGY 2021; 27:1755-1771. [PMID: 33319455 DOI: 10.1111/gcb.15484] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 12/08/2020] [Indexed: 06/12/2023]
Abstract
Species conservation in a rapidly changing world requires an improved understanding of how individuals and populations respond to changes in their environment across temporal scales. Increased warming in the Arctic puts this region at particular risk for rapid environmental change, with potentially devastating impacts on resident populations. Here, we make use of a parameterized full life cycle, individual-based energy budget model for wild muskoxen, coupling year-round environmental data with detailed ontogenic metabolic physiology. We show how winter food accessibility, summer food availability, and density dependence drive seasonal dynamics of energy storage and thus life history and population dynamics. Winter forage accessibility defined by snow depth, more than summer forage availability, was the primary determinant of muskox population dynamics through impacts on calf recruitment and longer term carryover effects of maternal investment. Simulations of various seasonal snow depth and plant biomass and quality profiles revealed that timing of and improved/limited winter forage accessibility had marked influence on calf recruitment (±10-80%). Impacts on recruitment were the cumulative result of condition-driven reproductive performance at multiple time points across the reproductive period (ovulation to calf weaning) as a trade-off between survival and reproduction. Seasonal and generational condition effects of snow-rich winters interacted with age structure and density to cause pronounced long-term consequences on population growth and structure, with predicted population recovery times from even moderate disturbances of 10 years or more. Our results show how alteration in winter forage accessibility, mediated by snow depth, impacts the dynamics of northern herbivore populations. Further, we present here a mechanistic and state-based model framework to assess future scenarios of environmental change, such as increased or decreased snowfall or plant biomass and quality to impact winter and summer forage availability across the Arctic.
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Affiliation(s)
- Jean-Pierre Desforges
- Bioscience Department, Aarhus University, Roskilde, Denmark
- Arctic Research Centre, Aarhus University, Aarhus, Denmark
- Department of Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, QC, Canada
| | - Gonçalo M Marques
- Marine, Environment & Technology Center (MARETEC, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Larissa T Beumer
- Bioscience Department, Aarhus University, Roskilde, Denmark
- Arctic Research Centre, Aarhus University, Aarhus, Denmark
| | | | - Lars H Hansen
- Bioscience Department, Aarhus University, Roskilde, Denmark
- Arctic Research Centre, Aarhus University, Aarhus, Denmark
| | - Stine Højlund Pedersen
- Cooperative Institute for Research in the Atmosphere (CIRA, Colorado State University, Fort Collins, CO, USA
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, USA
| | - Niels M Schmidt
- Bioscience Department, Aarhus University, Roskilde, Denmark
- Arctic Research Centre, Aarhus University, Aarhus, Denmark
| | - Floris M van Beest
- Bioscience Department, Aarhus University, Roskilde, Denmark
- Arctic Research Centre, Aarhus University, Aarhus, Denmark
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9
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Desforges J, van Beest FM, Marques GM, Pedersen SH, Beumer LT, Chimienti M, Schmidt NM. Quantifying energetic and fitness consequences of seasonal heterothermy in an Arctic ungulate. Ecol Evol 2021; 11:338-351. [PMID: 33437433 PMCID: PMC7790657 DOI: 10.1002/ece3.7049] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 10/19/2020] [Accepted: 10/29/2020] [Indexed: 11/09/2022] Open
Abstract
Animals have adapted behavioral and physiological strategies to conserve energy during periods of adverse conditions. Heterothermy is one such adaptation used by endotherms. While heterothermy-fluctuations in body temperature and metabolic rate-has been shown in large vertebrates, little is known of the costs and benefits of this strategy, both in terms of energy and in terms of fitness. Hence, our objective was to model the energetics of seasonal heterothermy in the largest Arctic ungulate, the muskox (Ovibos moschatus), using an individual-based energy budget model of metabolic physiology. We found that the empirically based drop in body temperature (winter max ~-0.8°C) overwinter in adult females resulted in substantial fitness benefits in terms of reduced daily energy expenditure and body mass loss. Body mass and energy reserves were 8.98% and 14.46% greater in modeled heterotherms compared to normotherms by end of winter. Based on environmental simulations, we show that seasonal heterothermy can, to some extent, buffer the negative consequences of poor prewinter body condition or reduced winter food accessibility, leading to greater winter survival (+20%-30%) and spring energy reserves (+10%-30%), and thus increased probability of future reproductive success. These results indicate substantial adaptive short-term benefits of seasonal heterothermy at the individual level, with potential implications for long-term population dynamics in highly seasonal environments.
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Affiliation(s)
- Jean‐Pierre Desforges
- Bioscience DepartmentAarhus UniversityRoskildeDenmark
- Arctic Research CentreAarhus UniversityAarhusDenmark
- Department of Natural Resource SciencesMcGill UniversitySte‐Anne‐de‐BellevueQCCanada
| | - Floris M. van Beest
- Bioscience DepartmentAarhus UniversityRoskildeDenmark
- Arctic Research CentreAarhus UniversityAarhusDenmark
| | - Gonçalo M. Marques
- Marine, Environment & Technology Center (MARETEC)Instituto Superior TécnicoUniversidade de LisboaLisboaPortugal
| | - Stine H. Pedersen
- Department of Biological SciencesUniversity of Alaska AnchorageAnchorageAKUSA
- Cooperative Institute for Research in the AtmosphereColorado State UniversityFort CollinsCOUSA
| | | | | | - Niels Martin Schmidt
- Bioscience DepartmentAarhus UniversityRoskildeDenmark
- Arctic Research CentreAarhus UniversityAarhusDenmark
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10
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Denryter K, German DW, Stephenson TR, Monteith KL. State- and context-dependent applications of an energetics model in free-ranging bighorn sheep. Ecol Modell 2021. [DOI: 10.1016/j.ecolmodel.2020.109349] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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11
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Smit C, Javal M, Lehmann P, Terblanche JS. Metabolic responses to starvation and feeding contribute to the invasiveness of an emerging pest insect. JOURNAL OF INSECT PHYSIOLOGY 2021; 128:104162. [PMID: 33189714 DOI: 10.1016/j.jinsphys.2020.104162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 11/10/2020] [Accepted: 11/10/2020] [Indexed: 06/11/2023]
Abstract
Metabolic rate, and the flexibility thereof, is a complex trait involving several inter-linked variables that can influence animal energetics, behavior, and ultimately, fitness. Metabolic traits respond readily to ambient temperature variation, in some cases increasing relative or absolute energetic costs, while in other cases, depending on the organism's metabolic and behavioral responses to changing conditions, resulting in substantial energy savings. To gain insight into the rapid recent emergence of the indigenous South African longhorn beetle Cacosceles newmannii as a crop pest in sugarcane, a better understanding of its metabolic rate, feeding response, digestion times, and aerobic scope is required, in conjunction with any behavioral responses to food availability or limitation thereof. Here, we therefore experimentally determined metabolic rate, estimated indirectly as CO2 production using flow-through respirometry, in starved, fasted, and fed C. newmannii larvae, at 20 °C and 30 °C. We estimated multiple parameters of metabolic rate (starved, standard, active, and maximum metabolic rates) as well as aerobic scope (AS), specific dynamic action (SDA), and the percentage time active during respirometry trials. Additionally, in individuals that showed cyclic or discontinuous gas exchange patterns, we compared rate, volume, and duration of cycles, and how these were influenced by temperature. Standard and active metabolic rate, and AS and SDA were significantly higher in the larvae measured at 30 °C than those measured at 20 °C. By contrast, starved and maximum metabolic rates and percentage time active were unaffected by temperature. At rest and after digestion was complete, 35% of larvae showed cyclic gas exchange at both temperatures; 5% and 15% showed continuous gas exchange at 20 °C and 30 °C respectively, and 10% and 0% showed discontinuous gas exchange at 20 °C and 30 °C respectively. We propose that the ability of C. newmannii larvae to survive extended periods of resource limitation, combined with a rapid ability to process food upon securing resources, even at cooler conditions that would normally suppress digestion in tropical insects, may have contributed to their ability to feed on diverse low energy resources typical of their host plants, and become pests of, and thrive on, a high energy host plant like sugarcane.
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Affiliation(s)
- Chantelle Smit
- Centre for Invasion Biology, Department of Conservation Ecology & Entomology, Faculty of AgriSciences, Stellenbosch University, South Africa
| | - Marion Javal
- Centre for Invasion Biology, Department of Conservation Ecology & Entomology, Faculty of AgriSciences, Stellenbosch University, South Africa
| | - Philipp Lehmann
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
| | - John S Terblanche
- Centre for Invasion Biology, Department of Conservation Ecology & Entomology, Faculty of AgriSciences, Stellenbosch University, South Africa.
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12
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Silva WTAF, Harding KC, Marques GM, Bäcklin BM, Sonne C, Dietz R, Kauhala K, Desforges JP. Life cycle bioenergetics of the gray seal (Halichoerus grypus) in the Baltic Sea: Population response to environmental stress. ENVIRONMENT INTERNATIONAL 2020; 145:106145. [PMID: 33038624 DOI: 10.1016/j.envint.2020.106145] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 05/21/2023]
Abstract
Wildlife population dynamics are shaped by multiple natural and anthropogenic factors, including predation, competition, stressful life history events, and external environmental stressors such as diseases and pollution. Marine mammals such as gray seals rely on extensive blubber layers for insulation and energy storage, making this tissue critical for survival and reproduction. This lipid rich blubber layer also accumulates hazardous fat soluble pollutants, such as polychlorinated biphenyls (PCBs), that can directly impact adipose function or be mobilized during periods of negative energy balance or transferred to offspring to exert further impacts on target tissues or vulnerable life stages. To predict how marine mammals will respond to ecological and anthropogenic stressors, it is necessary to use process-based modelling approaches that integrate environmental inputs, full species life history, and stressor impacts with individual dynamics of energy intake, storage, and utilization. The purpose of this study was to develop a full lifecycle dynamic energy budget and individual based model (DEB-IBM) that captured Baltic gray seal physiology and life history, and showcase potential applications of the model to predict population responses to select stressors known to threaten gray seals and other marine mammals around the world. We explore variations of three ecologically important stressors using phenomenological simulations: food limitation, endocrine disrupting chemicals that reduce fertility, and infectious disease. Using our calibrated DEB-IBM for Baltic gray seals, we found that continuous incremental food limitation can be more detrimental to population size than short random events of starvation, and further, that the effect of endocrine disruptors on population growth and structure is delayed due to bioaccumulation, and that communicable diseases significantly decrease population growth even when spillover events are relatively less frequent. One important finding is the delayed effect on population growth rate from some stressors, several years after the exposure period, resulting from a decline in somatic growth, increased age at maturation and decreased fecundity. Such delayed responses are ignored in current models of population viability and can be important in the correct assessment of population extinction risks. The model presented here provides a test bed on which effects of new hazardous substances and different scenarios of future environmental change affecting food availability and/or seal energetic demands can be investigated. Thus, the framework provides a tool for better understanding how diverse environmental stressors affect marine mammal populations and can be used to guide scientifically based management.
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Affiliation(s)
- Willian T A F Silva
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden.
| | - Karin C Harding
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Gonçalo M Marques
- Marine, Environment & Technology Center (MARETEC), Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | | | - Christian Sonne
- Department of Bioscience, Arctic Research Centre, Aarhus University, Roskilde, Denmark
| | - Rune Dietz
- Department of Bioscience, Arctic Research Centre, Aarhus University, Roskilde, Denmark
| | - Kaarina Kauhala
- Natural Resources Institute Finland, Itäinen Pitkäkatu, Turku, Finland
| | - Jean-Pierre Desforges
- Department of Bioscience, Arctic Research Centre, Aarhus University, Roskilde, Denmark; Department of Natural Resource Sciences, McGill University, Ste Anne de Bellevue, Canada.
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13
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Energetics as common currency for integrating high resolution activity patterns into dynamic energy budget-individual based models. Ecol Modell 2020. [DOI: 10.1016/j.ecolmodel.2020.109250] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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14
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van Beest FM, Beumer LT, Chimienti M, Desforges JP, Huffeldt NP, Pedersen SH, Schmidt NM. Environmental conditions alter behavioural organization and rhythmicity of a large Arctic ruminant across the annual cycle. ROYAL SOCIETY OPEN SCIENCE 2020; 7:201614. [PMID: 33204486 PMCID: PMC7657931 DOI: 10.1098/rsos.201614] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 10/07/2020] [Indexed: 06/11/2023]
Abstract
The existence and persistence of rhythmicity in animal activity during phases of environmental change is of interest in ecology, evolution and chronobiology. A wide diversity of biological rhythms in response to exogenous conditions and internal stimuli have been uncovered, especially for polar vertebrates. However, empirical data supporting circadian organization in behaviour of large ruminating herbivores remains inconclusive. Using year-round tracking data of the largest Arctic ruminant, the muskox (Ovibos moschatus), we modelled rhythmicity as a function of behaviour and environmental conditions. Behavioural states were classified based on patterns in hourly movements, and incorporated within a periodicity analyses framework. Although circadian rhythmicity in muskox behaviour was detected throughout the year, ultradian rhythmicity was most prevalent, especially when muskoxen were foraging and resting in mid-winter (continuous darkness). However, when combining circadian and ultradian rhythmicity together, the probability of behavioural rhythmicity declined with increasing photoperiod until largely disrupted in mid-summer (continuous light). Individuals that remained behaviourally rhythmic during mid-summer foraged in areas with lower plant productivity (NDVI) than individuals with arrhythmic behaviour. Based on our study, we conclude that muskoxen may use an interval timer to schedule their behavioural cycles when forage resources are low, but that the importance and duration of this timer are reduced once environmental conditions allow energetic reserves to be replenished ad libitum. We argue that alimentary function and metabolic requirements are critical determinants of biological rhythmicity in muskoxen, which probably applies to ruminating herbivores in general.
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Affiliation(s)
- Floris M. van Beest
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
- Arctic Research Centre, Aarhus University, Ny Munkegade 116, 8000 Aarhus C, Denmark
| | - Larissa T. Beumer
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
- Arctic Research Centre, Aarhus University, Ny Munkegade 116, 8000 Aarhus C, Denmark
| | - Marianna Chimienti
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Jean-Pierre Desforges
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
- Natural Resource Sciences, McGill University, Ste Anne de Bellevue, QuebecCanada, H9X 3V9
| | - Nicholas Per Huffeldt
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
- Greenland Institute of Natural Resources, 3900 Nuuk, Greenland
| | - Stine Højlund Pedersen
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, USA
- Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO, USA
| | - Niels Martin Schmidt
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
- Arctic Research Centre, Aarhus University, Ny Munkegade 116, 8000 Aarhus C, Denmark
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15
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Stubbs JL, Marn N, Vanderklift MA, Fossette S, Mitchell NJ. Simulated growth and reproduction of green turtles (Chelonia mydas) under climate change and marine heatwave scenarios. Ecol Modell 2020. [DOI: 10.1016/j.ecolmodel.2020.109185] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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16
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Stephenson TR, German DW, Cassirer EF, Walsh DP, Blum ME, Cox M, Stewart KM, Monteith KL. Linking population performance to nutritional condition in an alpine ungulate. J Mammal 2020; 101:1244-1256. [PMID: 33335453 PMCID: PMC7733374 DOI: 10.1093/jmammal/gyaa091] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 07/10/2020] [Indexed: 11/14/2022] Open
Abstract
Bighorn sheep (Ovis canadensis) can live in extremely harsh environments and subsist on submaintenance diets for much of the year. Under these conditions, energy stored as body fat serves as an essential reserve for supplementing dietary intake to meet metabolic demands of survival and reproduction. We developed equations to predict ingesta-free body fat in bighorn sheep using ultrasonography and condition scores in vivo and carcass measurements postmortem. We then used in vivo equations to investigate the relationships between body fat, pregnancy, overwinter survival, and population growth in free-ranging bighorn sheep in California and Nevada. Among 11 subpopulations that included alpine winter residents and migrants, mean ingesta-free body fat of lactating adult females during autumn ranged between 8.8% and 15.0%; mean body fat for nonlactating females ranged from 16.4% to 20.9%. In adult females, ingesta-free body fat > 7.7% during January (early in the second trimester) corresponded with a > 90% probability of pregnancy and ingesta-free body fat > 13.5% during autumn yielded a probability of overwinter survival > 90%. Mean ingesta-free body fat of lactating females in autumn was positively associated with finite rate of population increase (λ) over the subsequent year in bighorn sheep subpopulations that wintered in alpine landscapes. Bighorn sheep with ingesta-free body fat of 26% in autumn and living in alpine environments possess energy reserves sufficient to meet resting metabolism for 83 days on fat reserves alone. We demonstrated that nutritional condition can be a pervasive mechanism underlying demography in bighorn sheep and characterizes the nutritional value of their occupied ranges. Mountain sheep are capital survivors in addition to being capital breeders, and because they inhabit landscapes with extreme seasonal forage scarcity, they also can be fat reserve obligates. Quantifying nutritional condition is essential for understanding the quality of habitats, how it underpins demography, and the proximity of a population to a nutritional threshold.
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Affiliation(s)
- Thomas R Stephenson
- Sierra Nevada Bighorn Sheep Recovery Program, California Department of Fish and Wildlife, Bishop, CA, USA
| | - David W German
- Sierra Nevada Bighorn Sheep Recovery Program, California Department of Fish and Wildlife, Bishop, CA, USA
| | | | | | - Marcus E Blum
- Department of Natural Resources and Environmental Science, University of Nevada, Reno, NV, USA
| | - Mike Cox
- Nevada Department of Wildlife, Reno, NV, USA
| | - Kelley M Stewart
- Department of Natural Resources and Environmental Science, University of Nevada, Reno, NV, USA
| | - Kevin L Monteith
- Haub School of the Environment, Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA (KLM)
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17
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Beumer LT, Pohle J, Schmidt NM, Chimienti M, Desforges JP, Hansen LH, Langrock R, Pedersen SH, Stelvig M, van Beest FM. An application of upscaled optimal foraging theory using hidden Markov modelling: year-round behavioural variation in a large arctic herbivore. MOVEMENT ECOLOGY 2020; 8:25. [PMID: 32518653 PMCID: PMC7275509 DOI: 10.1186/s40462-020-00213-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 05/18/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND In highly seasonal environments, animals face critical decisions regarding time allocation, diet optimisation, and habitat use. In the Arctic, the short summers are crucial for replenishing body reserves, while low food availability and increased energetic demands characterise the long winters (9-10 months). Under such extreme seasonal variability, even small deviations from optimal time allocation can markedly impact individuals' condition, reproductive success and survival. We investigated which environmental conditions influenced daily, seasonal, and interannual variation in time allocation in high-arctic muskoxen (Ovibos moschatus) and evaluated whether results support qualitative predictions derived from upscaled optimal foraging theory. METHODS Using hidden Markov models (HMMs), we inferred behavioural states (foraging, resting, relocating) from hourly positions of GPS-collared females tracked in northeast Greenland (28 muskox-years). To relate behavioural variation to environmental conditions, we considered a wide range of spatially and/or temporally explicit covariates in the HMMs. RESULTS While we found little interannual variation, daily and seasonal time allocation varied markedly. Scheduling of daily activities was distinct throughout the year except for the period of continuous daylight. During summer, muskoxen spent about 69% of time foraging and 19% resting, without environmental constraints on foraging activity. During winter, time spent foraging decreased to 45%, whereas about 43% of time was spent resting, mediated by longer resting bouts than during summer. CONCLUSIONS Our results clearly indicate that female muskoxen follow an energy intake maximisation strategy during the arctic summer. During winter, our results were not easily reconcilable with just one dominant foraging strategy. The overall reduction in activity likely reflects higher time requirements for rumination in response to the reduction of forage quality (supporting an energy intake maximisation strategy). However, deep snow and low temperatures were apparent constraints to winter foraging, hence also suggesting attempts to conserve energy (net energy maximisation strategy). Our approach provides new insights into the year-round behavioural strategies of the largest Arctic herbivore and outlines a practical example of how to approximate qualitative predictions of upscaled optimal foraging theory using multi-year GPS tracking data.
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Affiliation(s)
- Larissa T. Beumer
- Department of Bioscience, Aarhus University, 4000 Roskilde, Denmark
- Arctic Research Centre, Aarhus University, 8000 Aarhus, Denmark
| | - Jennifer Pohle
- Department of Business Administration and Economics, Bielefeld University, 33615 Bielefeld, Germany
| | - Niels M. Schmidt
- Department of Bioscience, Aarhus University, 4000 Roskilde, Denmark
- Arctic Research Centre, Aarhus University, 8000 Aarhus, Denmark
| | | | - Jean-Pierre Desforges
- Department of Bioscience, Aarhus University, 4000 Roskilde, Denmark
- Arctic Research Centre, Aarhus University, 8000 Aarhus, Denmark
- Natural Resource Sciences, McGill University, Ste Anne de Bellevue, Quebec, H9X 3V9 Canada
| | - Lars H. Hansen
- Department of Bioscience, Aarhus University, 4000 Roskilde, Denmark
- Arctic Research Centre, Aarhus University, 8000 Aarhus, Denmark
| | - Roland Langrock
- Department of Business Administration and Economics, Bielefeld University, 33615 Bielefeld, Germany
| | - Stine Højlund Pedersen
- Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO 80523 USA
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK 99508 USA
| | | | - Floris M. van Beest
- Department of Bioscience, Aarhus University, 4000 Roskilde, Denmark
- Arctic Research Centre, Aarhus University, 8000 Aarhus, Denmark
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18
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Barboza PS, Shively RD, Gustine DD, Addison JA. Winter Is Coming: Conserving Body Protein in Female Reindeer, Caribou, and Muskoxen. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00150] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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19
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On the interplay between hypothermia and reproduction in a high arctic ungulate. Sci Rep 2020; 10:1514. [PMID: 32001737 PMCID: PMC6992616 DOI: 10.1038/s41598-020-58298-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 01/10/2020] [Indexed: 12/20/2022] Open
Abstract
For free-ranging animals living in seasonal environments, hypometabolism (lowered metabolic rate) and hypothermia (lowered body temperature) can be effective physiological strategies to conserve energy when forage resources are low. To what extent such strategies are adopted by large mammals living under extreme conditions, as those encountered in the high Arctic, is largely unknown, especially for species where the gestation period overlaps with the period of lowest resource availability (i.e. winter). Here we investigated for the first time the level to which high arctic muskoxen (Ovibos moschatus) adopt hypothermia and tested the hypothesis that individual plasticity in the use of hypothermia depends on reproductive status. We measured core body temperature over most of the gestation period in both free-ranging muskox females in Greenland and captive female muskoxen in Alaska. We found divergent overwintering strategies according to reproductive status, where pregnant females maintained stable body temperatures during winter, while non-pregnant females exhibited a temporary decrease in their winter body temperature. These results show that muskox females use hypothermia during periods of resource scarcity, but also that the use of this strategy may be limited to non-reproducing females. Our findings suggest a trade-off between metabolically-driven energy conservation during winter and sustaining foetal growth, which may also apply to other large herbivores living in highly seasonal environments elsewhere.
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