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Ren S, Zhang L, Tang X, Zhao Y, Cheng Q, Speakman JR, Zhang Y. Temporal and spatial variations in body mass and thermogenic capacity associated with alterations in the gut microbiota and host transcriptome in mammalian herbivores. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 907:167776. [PMID: 37848151 DOI: 10.1016/j.scitotenv.2023.167776] [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: 07/12/2023] [Revised: 10/07/2023] [Accepted: 10/10/2023] [Indexed: 10/19/2023]
Abstract
Most wild animals follow Bergmann's rule and grow in body size as cold stress increases. However, the underlying thermogenic strategies and their relationship with the gut microbiota have not been comprehensively elucidated. Herein, we used the plateau pikas as a model to investigate body mass, thermogenic capacity, host transcriptome, gut microbiota and metabolites collected from seven sites ranging from 3100 to 4700 m on the Qinghai-Tibetan Plateau (QTP) in summer and winter to test the seasonal thermogenesis strategy in small herbivorous mammals. The results showed that the increase in pika body mass with altitude followed Bergmann's rule in summer and an inverted parabolic shape was observed in winter. However, physiological parameters and transcriptome profiles indicated that the thermogenic capacity of pikas increased with altitude in summer and decreased with altitude in winter. The abundance of Firmicutes declined, whereas that of Bacteroidetes significantly increased with altitude in summer. Phenylalanine, tyrosine, and proline were enriched in summer, whereas carnitine and succinate were enriched in winter. Spearman's correlation analysis revealed significant positive correlations between Prevotella, Bacteroides, Ruminococcus, Alistipes and Akkermansia and metabolites of amino acids, pika physiological parameters, and transcriptome profiles. Moreover, metabolites of amino acids further showed significant positive correlations with pika physiological parameters and transcriptome profiles. Our study highlights that the changes in body mass and thermogenic capacity with altitude distinctly differentiate small herbivorous mammals between summer and winter on the QTP, and that the gut microbiota may regulate host thermogenesis through its metabolites.
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Affiliation(s)
- Shien Ren
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China; Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Xining 810008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liangzhi Zhang
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China; Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Xining 810008, China
| | - Xianjiang Tang
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China; Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Xining 810008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yaqi Zhao
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China; Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Xining 810008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qi Cheng
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China; Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Xining 810008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - John R Speakman
- Shenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China; Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - Yanming Zhang
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China; Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Xining 810008, China.
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2
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Wishart AE, Guerrero-Chacón AL, Smith R, Hawkshaw DM, McAdam AG, Dantzer B, Boutin S, Lane JE. Inferring condition in wild mammals: body condition indices confer no benefit over measuring body mass across ecological contexts. Oecologia 2024; 204:161-172. [PMID: 38180565 DOI: 10.1007/s00442-023-05495-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 11/30/2023] [Indexed: 01/06/2024]
Abstract
Many studies assume that it is beneficial for individuals of a species to be heavier, or have a higher body condition index (BCI), without accounting for the physiological relevance of variation in the composition of different body tissues. We hypothesized that the relationship between BCI and masses of physiologically important tissues (fat and lean) would be conditional on annual patterns of energy acquisition and expenditure. We studied three species with contrasting ecologies in their respective natural ranges: an obligate hibernator (Columbian ground squirrel, Urocitellus columbianus), a facultative hibernator (black-tailed prairie dog, Cynomys ludovicianus), and a food-caching non-hibernator (North American red squirrel, Tamiasciurus hudsonicus). We measured fat and lean mass in adults of both sexes using quantitative magnetic resonance (QMR). We measured body mass and two measures of skeletal structure (zygomatic width and right hind foot length) to develop sex- and species-specific BCIs, and tested the utility of BCI to predict body composition in each species. Body condition indices were more consistently, and more strongly correlated, with lean mass than fat mass. The indices were most positively correlated with fat when fat was expected to be very high (pre-hibernation prairie dogs). In all cases, however, BCI was never better than body mass alone in predicting fat or lean mass. While the accuracy of BCI in estimating fat varied across the natural histories and annual energetic patterns of the species considered, measuring body mass alone was as effective, or superior in capturing sufficient variation in fat and lean in most cases.
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Affiliation(s)
- Andrea E Wishart
- Department of Biology, University of Saskatchewan, Saskatoon, SK, S7N 5E2, Canada.
| | | | - Rebecca Smith
- Department of Biology, University of Saskatchewan, Saskatoon, SK, S7N 5E2, Canada
| | - Deborah M Hawkshaw
- Department of Biology, University of Saskatchewan, Saskatoon, SK, S7N 5E2, Canada
| | - Andrew G McAdam
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - Ben Dantzer
- Department of Psychology, University of Michigan, Ann Arbor, MI, 48109-1043, USA
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109-1043, USA
| | - Stan Boutin
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Jeffrey E Lane
- Department of Biology, University of Saskatchewan, Saskatoon, SK, S7N 5E2, Canada
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3
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McGrosky A, Pontzer H. The fire of evolution: energy expenditure and ecology in primates and other endotherms. J Exp Biol 2023; 226:297166. [PMID: 36916459 DOI: 10.1242/jeb.245272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Total energy expenditure (TEE) represents the total energy allocated to growth, reproduction and body maintenance, as well as the energy expended on physical activity. Early experimental work in animal energetics focused on the costs of specific tasks (basal metabolic rate, locomotion, reproduction), while determination of TEE was limited to estimates from activity budgets or measurements of subjects confined to metabolic chambers. Advances in recent decades have enabled measures of TEE in free-living animals, challenging traditional additive approaches to understanding animal energy budgets. Variation in lifestyle and activity level can impact individuals' TEE on short time scales, but interspecific differences in TEE are largely shaped by evolution. Here, we review work on energy expenditure across the animal kingdom, with a particular focus on endotherms, and examine recent advances in primate energetics. Relative to other placental mammals, primates have low TEE, which may drive their slow pace of life and be an evolved response to the challenges presented by their ecologies and environments. TEE variation among hominoid primates appears to reflect adaptive shifts in energy throughput and allocation in response to ecological pressures. As the taxonomic breadth and depth of TEE data expand, we will be able to test additional hypotheses about how energy budgets are shaped by environmental pressures and explore the more proximal mechanisms that drive intra-specific variation in energy expenditure.
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Affiliation(s)
- Amanda McGrosky
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Herman Pontzer
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA.,Duke Global Health Institute, Durham, NC 27708, USA
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4
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Kennah JL, Peers MJL, Vander Wal E, Majchrzak YN, Menzies AK, Studd EK, Boonstra R, Humphries MM, Jung TS, Kenney AJ, Krebs CJ, Boutin S. Coat color mismatch improves survival of a keystone boreal herbivore: Energetic advantages exceed lost camouflage. Ecology 2023; 104:e3882. [PMID: 36208219 DOI: 10.1002/ecy.3882] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 07/25/2022] [Indexed: 02/03/2023]
Abstract
Climate warming is causing asynchronies between animal phenology and environments. Mismatched traits, such as coat color change mismatched with snow, can decrease survival. However, coat change does not serve a singular adaptive benefit of camouflage, and alternate coat change functions may confer advantages that supersede mismatch costs. We found that mismatch reduced, rather than increased, autumn mortality risk of snowshoe hares in Yukon by 86.5% when mismatch occurred. We suggest that the increased coat insulation and lower metabolic rates of winter-acclimatized hares confer energetic advantages to white mismatched hares that reduce their mortality risk. We found that white mismatched hares forage 17-77 min less per day than matched brown hares between 0°C and -10°C, thus lowering their predation risk and increasing survival. We found no effect of mismatch on spring mortality risk, during which mismatch occurred at warmer temperatures, suggesting a potential temperature limit at which the costs of conspicuousness outweigh energetic benefits.
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Affiliation(s)
- Joanie L Kennah
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Michael J L Peers
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Eric Vander Wal
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Yasmine N Majchrzak
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Allyson K Menzies
- Department of Natural Resource Sciences, McGill University, Montreal, Quebec, Canada
| | - Emily K Studd
- Department of Natural Resource Sciences, McGill University, Montreal, Quebec, Canada
| | - Rudy Boonstra
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Murray M Humphries
- Department of Natural Resource Sciences, McGill University, Montreal, Quebec, Canada
| | - Thomas S Jung
- Department of Environment, Government of Yukon, Whitehorse, Yukon, Canada.,Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Alice J Kenney
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Charles J Krebs
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Stan Boutin
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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5
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Petrullo L, Delaney D, Boutin S, McAdam AG, Lane JE, Boonstra R, Palme R, Dantzer B. The glucocorticoid response to environmental change is not specific to agents of natural selection in wild red squirrels. Horm Behav 2022; 146:105262. [PMID: 36191397 DOI: 10.1016/j.yhbeh.2022.105262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/30/2022] [Accepted: 09/07/2022] [Indexed: 11/04/2022]
Abstract
Evolutionary endocrinology aims to understand how natural selection shapes endocrine systems and the degree to which endocrine systems themselves can induce phenotypic responses to environmental changes. Such responses may be specialized in that they reflect past selection for responsiveness only to those ecological factors that ultimately influence natural selection. Alternatively, endocrine responses may be broad and generalized, allowing organisms to cope with a variety of environmental changes simultaneously. Here, we empirically tested whether the endocrine response of female North American red squirrels (Tamiasciurus hudsonicus) was specialized or generalized. We first quantified the direction and magnitude of natural selection acting on three female life history traits (parturition date, litter size, offspring postnatal growth rate) during 32 years of fluctuations in four potential ecological agents of selection (food availability, conspecific density, predator abundance, and temperature). Only three of the four variables (food, density, and predators) affected patterns of natural selection on female life history traits. We then quantified fecal glucocorticoid metabolites (FGMs) across 7 years and found that all four environmental variables, regardless of their effects on patterns of selection, were associated with glucocorticoid production. Our results provide support for a generalized, rather than specific, glucocorticoid response to environmental change that can integrate across multiple co-occurring environmental stressors.
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Affiliation(s)
- Lauren Petrullo
- Department of Psychology, University of Michigan, Ann Arbor, MI 48108, USA.
| | - David Delaney
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA
| | - Stan Boutin
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Andrew G McAdam
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA
| | - Jeffrey E Lane
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Rudy Boonstra
- Department of Biological Sciences, Centre for the Neurobiology of Stress, University of Toronto Scarborough, Toronto, ON M1C 1A6, Canada
| | - Rupert Palme
- Unit of Physiology, Pathophysiology and Experimental Endocrinology, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterina ̈rplatz 1, Vienna 1210, Austria
| | - Ben Dantzer
- Department of Psychology, University of Michigan, Ann Arbor, MI 48108, USA; Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48108, USA
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6
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Jolly SR, Scott AM, Aldred TR, Gilbert JH, Pauli JN. A method to sample small mammals in the subnivium. MAMMAL RES 2022. [DOI: 10.1007/s13364-022-00653-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2022]
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7
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Behavioural adjustments of predators and prey to wind speed in the boreal forest. Oecologia 2022; 200:349-358. [PMID: 36175692 DOI: 10.1007/s00442-022-05266-w] [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: 03/07/2022] [Accepted: 09/19/2022] [Indexed: 10/14/2022]
Abstract
Wind speed can have multifaceted effects on organisms including altering thermoregulation, locomotion, and sensory reception. While forest cover can substantially reduce wind speed at ground level, it is not known if animals living in forests show any behavioural responses to changes in wind speed. Here, we explored how three boreal forest mammals, a predator and two prey, altered their behaviour in response to average daily wind speeds during winter. We collected accelerometer data to determine wind speed effects on activity patterns and kill rates of free-ranging red squirrels (n = 144), snowshoe hares (n = 101), and Canada lynx (n = 27) in Kluane, Yukon from 2015 to 2018. All 3 species responded to increasing wind speeds by changing the time they were active, but effects were strongest in hares, which reduced daily activity by 25%, and lynx, which increased daily activity by 25%. Lynx also increased the number of feeding events by 40% on windy days. These results highlight that wind speed is an important abiotic variable that can affect behaviour, even in forested environments.
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8
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Staples JF, Mathers KE, Duffy BM. Mitochondrial Metabolism in Hibernation: Regulation and Implications. Physiology (Bethesda) 2022; 37:0. [PMID: 35658625 DOI: 10.1152/physiol.00006.2022] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Hibernators rapidly and reversibly suppress mitochondrial respiration and whole animal metabolism. Posttranslational modifications likely regulate these mitochondrial changes, which may help conserve energy in winter. These modifications are affected by reactive oxygen species (ROS), so suppressing mitochondrial ROS production may also be important for hibernators, just as it is important for surviving ischemia-reperfusion injury.
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Affiliation(s)
- James F Staples
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Katherine E Mathers
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Brynne M Duffy
- Department of Biology, University of Western Ontario, London, Ontario, Canada
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9
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Speakman JR, Elmquist JK. Obesity: an evolutionary context. LIFE METABOLISM 2022; 1:10-24. [PMID: 36394061 PMCID: PMC9642988 DOI: 10.1093/lifemeta/loac002] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 02/21/2022] [Accepted: 03/09/2022] [Indexed: 05/07/2023]
Abstract
People completely lacking body fat (lipodystrophy/lipoatrophy) and those with severe obesity both show profound metabolic and other health issues. Regulating levels of body fat somewhere between these limits would, therefore, appear to be adaptive. Two different models might be contemplated. More traditional is a set point (SP) where the levels are regulated around a fixed level. Alternatively, dual-intervention point (DIP) is a system that tolerates fairly wide variation but is activated when critically high or low levels are breached. The DIP system seems to fit our experience much better than an SP, and models suggest that it is more likely to have evolved. A DIP system may have evolved because of two contrasting selection pressures. At the lower end, we may have been selected to avoid low levels of fat as a buffer against starvation, to avoid disease-induced anorexia, and to support reproduction. At the upper end, we may have been selected to avoid excess storage because of the elevated risks of predation. This upper limit of control seems to have malfunctioned because some of us deposit large fat stores, with important negative health effects. Why has evolution not protected us against this problem? One possibility is that the protective system slowly fell apart due to random mutations after we dramatically reduced the risk of being predated during our evolutionary history. By chance, it fell apart more in some people than others, and these people are now unable to effectively manage their weight in the face of the modern food glut. To understand the evolutionary context of obesity, it is important to separate the adaptive reason for storing some fat (i.e. the lower intervention point), from the nonadaptive reason for storing lots of fat (a broken upper intervention point). The DIP model has several consequences, showing how we understand the obesity problem and what happens when we attempt to treat it.
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Affiliation(s)
- John R Speakman
- Corresponding author. John R Speakman, Shenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, Shenzhen, China. E-mail:
| | - Joel K Elmquist
- Joel K. Elmquist, Departments of Internal Medicine and Pharmacology, Center for Hypothalamic Research, University of Texas Southwestern, 5323 Harry Hines blvd., Dallas, TX 75390, USA. E-mail:
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Zhu H, Zhong L, Li J, Wang S, Qu J. Differential Expression of Metabolism-Related Genes in Plateau Pika ( Ochotona curzoniae) at Different Altitudes on the Qinghai-Tibet Plateau. Front Genet 2022; 12:784811. [PMID: 35126457 PMCID: PMC8811202 DOI: 10.3389/fgene.2021.784811] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 12/28/2021] [Indexed: 11/30/2022] Open
Abstract
According to life history theory, animals living in extreme environments have evolved specific behavioral and physiological strategies for survival. However, the genetic mechanisms underpinning these strategies are unclear. As the highest geographical unit on Earth, the Qinghai-Tibet Plateau is characterized by an extreme environment and climate. During long-term evolutionary processes, animals that inhabit the plateau have evolved specialized morphological and physiological traits. The plateau pika (Ochotona curzoniae), one of the native small mammals that evolved on the Qinghai-Tibet Plateau, has adapted well to this cold and hypoxic environment. To explore the genetic mechanisms underlying the physiological adaptations of plateau pika to extremely cold ambient temperatures, we measured the differences in resting metabolic rate (RMR) and metabolism-related gene expression in individuals inhabiting three distinct altitudes (i.e., 3,321, 3,663, and 4,194 m). Results showed that the body mass and RMR of plateau pika at high- and medium-altitudes were significantly higher than those at the low-altitude. The expression levels of peroxisome proliferator-activated receptor α (pparα), peroxisome proliferator-activated receptor-γ coactivator-1α (pgc-1α), and the PR domain-containing 16 (PRDM16) in white (WAT) and brown (BAT) adipose tissues of plateau pika from high- and medium-altitudes were significantly higher than in pika from the low-altitude region. The enhanced expression levels of pgc-1α and pparα genes in the WAT of pika at high-altitude showed that WAT underwent "browning" and increased thermogenic properties. An increase in the expression of uncoupling protein 1 (UCP1) in the BAT of pika at high altitude indicated that BAT increased their thermogenic properties. The gene expression levels of pparα and pgc-1α in skeletal muscles were significantly higher in high-altitude pika. Simultaneously, the expression of the sarcolipin (SLN) gene in skeletal muscles significantly increased in high-altitude pika. Our results suggest that plateau pika adapted to an extremely cold environment via browning WAT, thereby activating BAT and enhancing SLN expression to increase non-shivering thermogenesis. This study demonstrates that plateau pika can increase thermogenic gene expression and energy metabolism to adapt to the extreme environments on the plateau.
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Affiliation(s)
- Hongjuan Zhu
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Liang Zhong
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
- Qinghai Province Key Laboratory of Animal Ecological Genomics, Xining, China
| | - Jing Li
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Suqin Wang
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jiapeng Qu
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
- Qinghai Province Key Laboratory of Animal Ecological Genomics, Xining, China
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11
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Wang B, Zhang SQ, Dong JL, Li Y, Jin YX, Xiao HW, Wang HC, Fan SJ, Cui M. Ambient temperature structures the gut microbiota of zebrafish to impact the response to radioactive pollution. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 293:118539. [PMID: 34798219 DOI: 10.1016/j.envpol.2021.118539] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 11/08/2021] [Accepted: 11/15/2021] [Indexed: 06/13/2023]
Abstract
Potential nuclear accidents propel serious environmental pollution, and the resultant radionuclide release devastates severely the environment severely and threatens aquatic organism survival. Likewise, ongoing climate change coupled with the gradual increase in global surface temperatures can also adversely impact the aquatic ecosystems. In the present study, we preconditioned zebrafish (Danio rerio) at three different temperatures (18 °C, 26 °C and 34 °C) to investigate the effects of a temperature profile on their radiosensitivity (exposure to 20 Gy of gamma rays) to identify the potential biochemical mechanism responsible for influencing radiosensitivity. We found that preconditioning of zebrafish at different temperatures moulded specific gut microbiota configurations and impacted hepatic glycometabolism and sensitivity to subsequent radiation. Following antibiotic treatment to reduce gut bacteria, these observed differences in the expression of hepatic glycometabolism-related genes and radiation-induced intestinal toxicity were minimal, supporting the hypothesis that the gut bacteria reshaped by different ambient temperatures might be the key modulators of hepatic functions and radiosensitivity in zebrafish. Together, our findings provide novel insights into the connection of radiation injuries with temperature alterations in fish, and suggest that maintaining the stability of gram-positive bacteria may be efficacious to protect aquatic organisms against short or long-term radioactive contamination in the context of global climate change.
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Affiliation(s)
- Bin Wang
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Shu-Qin Zhang
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Jia-Li Dong
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Yuan Li
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Yu-Xiao Jin
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Hui-Wen Xiao
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Hai-Chao Wang
- The Feinstein Institutes for Medical Research, Northwell Health, 350 Community Drive, Manhasset, USA; Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, 500 Hofstra Blvd, Hempstead, USA
| | - Sai-Jun Fan
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Ming Cui
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China.
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12
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Balluffi-Fry J, Leroux SJ, Wiersma YF, Richmond IC, Heckford TR, Rizzuto M, Kennah JL, Vander Wal E. Integrating plant stoichiometry and feeding experiments: state-dependent forage choice and its implications on body mass. Oecologia 2021; 198:579-591. [PMID: 34743229 DOI: 10.1007/s00442-021-05069-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 10/22/2021] [Indexed: 10/19/2022]
Abstract
Intraspecific feeding choices comprise a large portion of herbivore foraging decisions. Plant resource quality is heterogeneously distributed, affected by nutrient availability and growing conditions. Herbivores navigate landscapes, foraging not only according to food qualities, but also energetic and nutritional demands. We test three non-exclusive foraging hypotheses using the snowshoe hare (Lepus americanus): (1) herbivore feeding choices and body conditions respond to intraspecific plant quality variation; (2) high energetic demands mitigate feeding responses; and (3) feeding responses are inflated when nutritional demands are high. We measured black spruce (Picea mariana) nitrogen, phosphorus and terpene compositions, as indicators of quality, within a snowshoe hare trapping grid and found plant growing conditions to explain spruce quality variation (R2 < 0.36). We then offered two qualities of spruce (H1) from the trapping grid to hares in cafeteria-style experiments and measured their feeding and body condition responses (n = 75). We proxied energetic demands (H2) with ambient temperature and coat insulation (% white coat) and nutritional demands (H3) with the spruce quality (nitrogen and phosphorus content) in home ranges. Hares with the strongest preference for high-quality spruce lost on average 2.2% less weight than hares who ate the least high-quality spruce relative to low-quality spruce. The results supported our energetic predictions as follows: hares in colder temperatures and with less-insulative coats (lower % white) consumed more spruce and were less selective towards high-quality spruce. Collectively, we found variation in plant growing conditions within herbivore home ranges substantial enough to affect herbivore body conditions, but energetic stats mediate plant-herbivore interactions.
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Affiliation(s)
- Juliana Balluffi-Fry
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada. .,Department of Biological Sciences, University of Alberta, CW 405, Biological Sciences Building, Edmonton, Alberta, T6G 2E9, Canada.
| | - Shawn J Leroux
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Yolanda F Wiersma
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Isabella C Richmond
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Travis R Heckford
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Matteo Rizzuto
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Joanie L Kennah
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Eric Vander Wal
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
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13
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Trondrud LM, Pigeon G, Albon S, Arnold W, Evans AL, Irvine RJ, Król E, Ropstad E, Stien A, Veiberg V, Speakman JR, Loe LE. Determinants of heart rate in Svalbard reindeer reveal mechanisms of seasonal energy management. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200215. [PMID: 34176322 PMCID: PMC8237166 DOI: 10.1098/rstb.2020.0215] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/03/2021] [Indexed: 02/02/2023] Open
Abstract
Seasonal energetic challenges may constrain an animal's ability to respond to changing individual and environmental conditions. Here, we investigated variation in heart rate, a well-established proxy for metabolic rate, in Svalbard reindeer (Rangifer tarandus platyrhynchus), a species with strong seasonal changes in foraging and metabolic activity. In 19 adult females, we recorded heart rate, subcutaneous temperature and activity using biologgers. Mean heart rate more than doubled from winter to summer. Typical drivers of energy expenditure, such as reproduction and activity, explained a relatively limited amount of variation (2-6% in winter and 16-24% in summer) compared to seasonality, which explained 75% of annual variation in heart rate. The relationship between heart rate and subcutaneous temperature depended on individual state via body mass, age and reproductive status, and the results suggested that peripheral heterothermy is an important pathway of energy management in both winter and summer. While the seasonal plasticity in energetics makes Svalbard reindeer well-adapted to their highly seasonal environment, intraseasonal constraints on modulation of their heart rate may limit their ability to respond to severe environmental change. This study emphasizes the importance of encompassing individual state and seasonal context when studying energetics in free-living animals. This article is part of the theme issue 'Measuring physiology in free-living animals (Part II)'.
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Affiliation(s)
- L. Monica Trondrud
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NO-1432 Ås, Norway
| | - Gabriel Pigeon
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NO-1432 Ås, Norway
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, 2500 boul. de l'Université, Sherbrooke, Québec, Canada, J1 K 2R1
| | - Steve Albon
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Walter Arnold
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Savoyenstr. 1, 1160 Vienna, Austria
| | - Alina L. Evans
- Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Campus Evenstad, 2418 Elverum, Norway
| | - R. Justin Irvine
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
- Frankfurt Zoological Society, PO Box 100003, South Africa Street, Addis Ababa, Ethiopia
| | - Elżbieta Król
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - Erik Ropstad
- Faculty of Veterinary Science, Norwegian University of Life Sciences, PO Box 8146, NO-0033 Oslo, Norway
| | - Audun Stien
- Department of Arctic and Marine Biology, The Arctic University of Norway, PO Box 6050 Langnes, NO-9037 Tromsø, Norway
| | - Vebjørn Veiberg
- Norwegian Institute for Nature Research, PO Box 5685 Torgarden, NO-7485 Trondheim, Norway
| | - John R. Speakman
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
- Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, People's Republic of China
- CAS Center of Excellence in Animal Evolution and Genetics, Kunming 650223, People's Republic of China
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Leif Egil Loe
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NO-1432 Ås, Norway
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14
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Surviving winter on the Qinghai-Tibetan Plateau: Pikas suppress energy demands and exploit yak feces to survive winter. Proc Natl Acad Sci U S A 2021; 118:2100707118. [PMID: 34282012 DOI: 10.1073/pnas.2100707118] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The Qinghai-Tibetan Plateau, with low precipitation, low oxygen partial pressure, and temperatures routinely dropping below -30 °C in winter, presents several physiological challenges to its fauna. Yet it is home to many endemic mammalian species, including the plateau pika (Ochotona curzoniae). How these small animals that are incapable of hibernation survive the winter is an enigma. Measurements of daily energy expenditure (DEE) using the doubly labeled water method show that pikas suppress their DEE during winter. At the same body weight, pikas in winter expend 29.7% less than in summer, despite ambient temperatures being approximately 25 °C lower. Combined with resting metabolic rates (RMRs), this gives them an exceptionally low metabolic scope in winter (DEE/RMRt = 1.60 ± 0.30; RMRt is resting metabolic rate at thermoneutrality). Using implanted body temperature loggers and filming in the wild, we show that this is achieved by reducing body temperature and physical activity. Thyroid hormone (T3 and T4) measurements indicate this metabolic suppression is probably mediated via the thyroid axis. Winter activity was lower at sites where domestic yak (Bos grunniens) densities were higher. Pikas supplement their food intake at these sites by eating yak feces, demonstrated by direct observation, identification of yak DNA in pika stomach contents, and greater convergence in the yak/pika microbiotas in winter. This interspecific coprophagy allows pikas to thrive where yak are abundant and partially explains why pika densities are higher where domestic yak, their supposed direct competitors for food, are more abundant.
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15
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Boratyński Z. Energetic constraints on mammalian distribution areas. J Anim Ecol 2021; 90:1854-1863. [PMID: 33884621 DOI: 10.1111/1365-2656.13501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 04/06/2021] [Indexed: 12/01/2022]
Abstract
Energy is a universal resource essential for all life functions. The rate of transformation of energy into an organism, and the energetic investment into reproduction, determines population and ecological-level processes. Several hypotheses predicted that the ecological expansion and size of the geographic distribution of a species are shaped by, among other factors, metabolic performance. However, how organismal energetic characteristics contribute to species geographic range size is poorly understood. With phylogenetic comparative methods whether energetic maintenance costs (basal metabolic rate, BMR), aerobic capacity (maximum exercise metabolic rate, VO2 max), summit thermoregulation (summit metabolic rate, VO2 sum) and the ability to sustain energy provisioning (daily energy expenditure, DEE) determine the distribution of mammalian species range sizes was tested. Both basal and maximum exercise metabolic rates (accounting for body mass), but not summit thermogenic metabolic rate, were positively associated with species range sizes. Furthermore, daily energy expenditure (accounting for body mass) was positively associated with species ranges. Body mass (accounting for energetic maintenance) was negatively related to range sizes. High aerobic exercise capacity, aiding mobility such as running and dispersal, and high sustained energy provisioning, aiding reproductive effort such as pregnancy, lactation and natal dispersal, can facilitate the establishment of large mammalian geographic ranges. Consequently, the pace of organismal physiological processes can shape important ecological and biodiversity patterns by setting limits to species' range sizes.
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Affiliation(s)
- Zbyszek Boratyński
- CIBIO/InBio, Research Centre in Biodiversity and Genetic Resources, University of Porto, Vairão, Portugal
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16
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Jebb AHM, Blumstein DT, Bize P, Martin JGA. Bigger is not always better: Viability selection on body mass varies across life stages in a hibernating mammal. Ecol Evol 2021; 11:3435-3445. [PMID: 33841795 PMCID: PMC8019046 DOI: 10.1002/ece3.7304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 11/30/2020] [Accepted: 12/18/2020] [Indexed: 11/30/2022] Open
Abstract
Body mass is often viewed as a proxy of past access to resources and of future survival and reproductive success. Links between body mass and survival or reproduction are, however, likely to differ between age classes and sexes. Remarkably, this is rarely taken into account in selection analyses. Selection on body mass is likely to be the primary target accounting for juvenile survival until reproduction but may weaken after recruitment. Males and females also often differ in how they use resources for reproduction and survival. Using a long-term study on body mass and annual survival in yellow-bellied marmots (Marmota flaviventer), we show that body mass was under stabilizing viability selection in the first years of life, before recruitment, which changed to positive directional selection as age increased and animals matured. We found no evidence that viability selection across age classes on body mass differed between sexes. By investigating the link between running speed and body mass, we show that the capacity to escape predators was not consistent across age classes and followed a quadratic relationship at young ages only. Overall, our results indicate that mature age classes exhibit traditional patterns of positive viability selection on body mass, as expected in a hibernating mammal, but that mass in the first years of life is subjected to stabilizing selection which may come from additional predation pressures that negate the benefits of the largest body masses. Our study highlights the importance to disentangle selection pressures on traits across critical age (or life) classes.
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Affiliation(s)
| | - Daniel T. Blumstein
- The Rocky Mountain Biological LaboratoryCrested ButteCOUSA
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaLos AngelesCAUSA
| | - Pierre Bize
- School of Biological SciencesUniversity of AberdeenAberdeenUK
| | - Julien G. A. Martin
- School of Biological SciencesUniversity of AberdeenAberdeenUK
- Department of BiologyUniversity of OttawaOttawaONCanada
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17
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Dantzer B, McAdam AG, Humphries MM, Lane JE, Boutin S. Decoupling the effects of food and density on life-history plasticity of wild animals using field experiments: Insights from the steward who sits in the shadow of its tail, the North American red squirrel. J Anim Ecol 2020; 89:2397-2414. [PMID: 32929740 DOI: 10.1111/1365-2656.13341] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 08/07/2020] [Indexed: 01/05/2023]
Abstract
Long-term studies of wild animals provide the opportunity to investigate how phenotypic plasticity is used to cope with environmental fluctuations and how the relationships between phenotypes and fitness can be dependent upon the ecological context. Many previous studies have only investigated life-history plasticity in response to changes in temperature, yet wild animals often experience multiple environmental fluctuations simultaneously. This requires field experiments to decouple which ecological factor induces plasticity in fitness-relevant traits to better understand their population-level responses to those environmental fluctuations. For the past 32 years, we have conducted a long-term integrative study of individually marked North American red squirrels Tamiasciurus hudsonicus Erxleben in the Yukon, Canada. We have used multi-year field experiments to examine the physiological and life-history responses of individual red squirrels to fluctuations in food abundance and conspecific density. Our long-term observational study and field experiments show that squirrels can anticipate increases in food availability and density, thereby decoupling the usual pattern where animals respond to, rather than anticipate, an ecological change. As in many other study systems, ecological factors that can induce plasticity (such as food and density) covary. However, our field experiments that manipulate food availability and social cues of density (frequency of territorial vocalizations) indicate that increases in social (acoustic) cues of density in the absence of additional food can induce similar life-history plasticity, as does experimental food supplementation. Changes in the levels of metabolic hormones (glucocorticoids) in response to variation in food and density are one mechanism that seems to induce this adaptive life-history plasticity. Although we have not yet investigated the energetic response of squirrels to elevated density or its association with life-history plasticity, energetics research in red squirrels has overturned several standard pillars of knowledge in physiological ecology. We show how a tractable model species combined with integrative studies can reveal how animals cope with resource fluctuations through life-history plasticity.
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Affiliation(s)
- Ben Dantzer
- Department of Psychology, University of Michigan, Ann Arbor, MI, USA.,Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Andrew G McAdam
- Department for Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO, USA
| | - Murray M Humphries
- Natural Resource Sciences Department, McGill University, Ste-Anne-de-Bellevue, QC, Canada
| | - Jeffrey E Lane
- Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Stan Boutin
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
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18
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Bonebrake TC, Rezende EL, Bozinovic F. Climate Change and Thermoregulatory Consequences of Activity Time in Mammals. Am Nat 2020; 196:45-56. [PMID: 32552099 DOI: 10.1086/709010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Activity times structure the thermal environments experienced by organisms. In mammals, species shift from being nocturnal to diurnal and vice versa, but the thermal consequences of variable activity patterns remain largely unexplored. Here we used theoretical thermoregulatory polygons bounded by estimates of basal metabolic rates (BMR), maximum metabolic rates (MMR), and thermal conductance (C) in small mammals to explore the metabolic consequences of exposure to global-scale daytime and nighttime temperatures. Model predictions indicated higher metabolic scope for activity for nocturnal species at low latitudes and that reduced minimum C and larger body size increased the geographic range in which nocturnality was advantageous. Consistent with predictions, within rodents nocturnal species have low C. However, nocturnal mammals tend to be smaller than diurnal species, likely reflecting the importance of additional factors driving body size. Projections of warming impacts on small mammals suggest that diurnal species could lose habitable space globally. Conversely, warming could lift cool temperature constraints on nocturnal species and increase habitable space, suggesting that a shift toward nocturnal niches might be favored in a warming world. Taken together, these findings demonstrate the importance of energetic considerations for endotherms in managing global change impacts on nocturnal and diurnal species.
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19
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Fisher JT, Burton AC, Nolan L, Roy L. Influences of landscape change and winter severity on invasive ungulate persistence in the Nearctic boreal forest. Sci Rep 2020; 10:8742. [PMID: 32457474 PMCID: PMC7250834 DOI: 10.1038/s41598-020-65385-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 04/22/2020] [Indexed: 11/15/2022] Open
Abstract
Climate and landscape change are drivers of species range shifts and biodiversity loss; understanding how they facilitate and sustain invasions has been empirically challenging. Winter severity is decreasing with climate change and is a predicted mechanism of contemporary and future range shifts. For example, white-tailed deer (Odocoileus virginianus) expansion is a continental phenomenon across the Nearctic with ecological consequences for entire biotic communities. We capitalized on recent temporal variation in winter severity to examine spatial and temporal dynamics of invasive deer distribution in the Nearctic boreal forest. We hypothesized deer distribution would decrease in severe winters reflecting historical climate constraints, and remain more static in moderate winters reflecting recent climate. Further, we predicted that regardless of winter severity, deer distribution would persist and be best explained by early seral forage subsidies from extensive landscape change via resource extraction. We applied dynamic occupancy models in time, and species distribution models in space, to data from 62 camera traps sampled over 3 years in northeastern Alberta, Canada. Deer distribution shrank more markedly in severe winters but rebounded each spring regardless of winter severity. Deer distribution was best explained by anthropogenic landscape features assumed to provide early seral vegetation subsidy, accounting for natural landcover. We conclude that deer dynamics in the northern boreal forest are influenced both by landscape change across space and winter severity through time, the latter expected to further decrease with climate change. We contend that the combined influence of these two drivers is likely pervasive for many species, with changing resources offsetting or augmenting physiological limitations.
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Affiliation(s)
- Jason T Fisher
- University of Victoria, School of Environmental Studies, Victoria, British, Columbia, Canada.
- Former address: InnoTech Alberta, Bag 4000, Vegreville, Alberta, T9C1T4, Canada.
| | - A Cole Burton
- Former address: InnoTech Alberta, Bag 4000, Vegreville, Alberta, T9C1T4, Canada
- University of British Columbia, Department of Forest Resources Management, Forest Sciences Centre, 2045 - 2424 Main Mall, Vancouver, British, Columbia, V6T1Z4, Canada
| | - Luke Nolan
- Former address: InnoTech Alberta, Bag 4000, Vegreville, Alberta, T9C1T4, Canada
| | - Laurence Roy
- Former address: InnoTech Alberta, Bag 4000, Vegreville, Alberta, T9C1T4, Canada
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20
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Studd EK, Menzies AK, Siracusa ER, Dantzer B, Lane JE, McAdam AG, Boutin S, Humphries MM. Optimisation of energetic and reproductive gains explains behavioural responses to environmental variation across seasons and years. Ecol Lett 2020; 23:841-850. [PMID: 32189469 DOI: 10.1111/ele.13494] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 12/09/2019] [Accepted: 02/21/2020] [Indexed: 12/31/2022]
Abstract
Animals switch between inactive and active states, simultaneously impacting their energy intake, energy expenditure and predation risk, and collectively defining how they engage with environmental variation and trophic interactions. We assess daily activity responses to long-term variation in temperature, resources and mating opportunities to examine whether individuals choose to be active or inactive according to an optimisation of the relative energetic and reproductive gains each state offers. We show that this simplified behavioural decision approach predicts most activity variation (R2 = 0.83) expressed by free-ranging red squirrels over 4 years, as quantified through accelerometer recordings (489 deployments; 5066 squirrel-days). Recognising activity as a determinant of energetic status, the predictability of activity variation aggregated at a daily scale, and the clear signal that behaviour is environmentally forced through optimisation of gain, provides an integrated approach to examine behavioural variation as an intermediary between environmental variation and energetic, life-history and ecological outcomes.
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Affiliation(s)
- E K Studd
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Bellevue, QC, Canada.,Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - A K Menzies
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Bellevue, QC, Canada
| | - E R Siracusa
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | - B Dantzer
- Department of Psychology, University of Michigan, Ann Arbor, MI, USA.,Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - J E Lane
- Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada
| | - A G McAdam
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - S Boutin
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - M M Humphries
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Bellevue, QC, Canada
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21
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Martin ME, Moriarty KM, Pauli JN. Forest structure and snow depth alter the movement patterns and subsequent expenditures of a forest carnivore, the Pacific marten. OIKOS 2019. [DOI: 10.1111/oik.06513] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Marie E. Martin
- Dept of Forest and Wildlife Ecology, Univ. of Wisconsin‐Madison, 1630 Linden Drive Madison WI USA
| | - Katie M. Moriarty
- Pacific Northwest Research Station, United States Forest Service Olympia WA USA
- National Council for Air and Stream Improvement, Inc. Corvallis OR USA
| | - Jonathan N. Pauli
- Dept of Forest and Wildlife Ecology, Univ. of Wisconsin‐Madison, 1630 Linden Drive Madison WI USA
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22
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Ding Y, Lyons SA, Scott GR, Gillis TE. Characterizing the influence of chronic hypobaric hypoxia on diaphragmatic myofilament contractile function and phosphorylation in high-altitude deer mice and low-altitude white-footed mice. J Comp Physiol B 2019; 189:489-499. [PMID: 31278612 DOI: 10.1007/s00360-019-01224-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 06/06/2019] [Accepted: 06/24/2019] [Indexed: 11/27/2022]
Abstract
Deer mice, Peromyscusmaniculatus, live at high altitudes where limited O2 represents a challenge to maintaining oxygen delivery to tissues. Previous work has demonstrated that hypoxia acclimation of deer mice and low altitude white-footed mice (P. leucopus) increases the force generating capacity of the diaphragm. The mechanism behind this improved contractile function is not known. Within myocytes, the myofilament plays a critical role in setting the rate and level of force production, and its ability to generate force can change in response to changes in physiological conditions. In the current study, we examined how chronic hypobaric hypoxia exposure of deer mice and white-footed mice influences the Ca2+ activation of force generation by skinned diaphragmatic myofilaments, and the phosphorylation of myofilament proteins. Results demonstrate that myofilament force production, and the Ca2+ sensitivity of force generation, were not impacted by acclimation to hypobaric hypoxia, and did not differ between preparations from the two species. The cooperativity of the force-pCa relationship, and the maximal rate of force generation were also the same in the preparations from both species, and not impacted by acclimation. Finally, the relative phosphorylation of TnT, and MLC was lower in deer mice than white-footed mice, but was not affected by acclimation. These results indicate that species differences in diaphragm function, and the increase in force production with hypoxia acclimation, are not due to differences, or changes, in myofilament function. However, it appears that diaphragmatic myofilament function in these species is not affected by chronic hypobaric hypoxia exposure.
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Affiliation(s)
- Y Ding
- Department of Integrative Biology, University of Guelph, Guelph, ON, N1G-2W1, Canada
| | - S A Lyons
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - G R Scott
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Todd E Gillis
- Department of Integrative Biology, University of Guelph, Guelph, ON, N1G-2W1, Canada.
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23
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Mendes CP, Koprowski JL, Galetti M. NEOSQUIRREL: a data set of ecological knowledge on Neotropical squirrels. Mamm Rev 2019. [DOI: 10.1111/mam.12152] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Calebe Pereira Mendes
- Laboratório de Biologia da Conservação (LABIC)Departamento de EcologiaInstituto de BiociênciasUniversidade Estadual Paulista (UNESP) Avenida 24A,1515, ZIP 13506‐900, Rio Claro São Paulo Brazil
| | - John L. Koprowski
- School of Natural Resources and the EnvironmentUniversity of Arizona Tucson AZ 85721 USA
| | - Mauro Galetti
- Departamento de EcologiaInstituto de BiociênciasUniversidade Estadual Paulista (UNESP) Rio Claro São Paulo Brazil
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24
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Snow roosting reduces temperature-associated stress in a wintering bird. Oecologia 2019; 190:309-321. [DOI: 10.1007/s00442-019-04389-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 03/19/2019] [Indexed: 12/19/2022]
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25
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Careau V, Beauchamp PP, Bouchard S, Morand-Ferron J. Energy metabolism and personality in wild-caught fall field crickets. Physiol Behav 2019; 199:173-181. [PMID: 30465808 DOI: 10.1016/j.physbeh.2018.11.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Revised: 11/13/2018] [Accepted: 11/17/2018] [Indexed: 11/16/2022]
Abstract
Standard metabolic rate (SMR) is known to be highly variable across levels of biological organisation (e.g., species, populations, among individuals, within individuals). Some of the variation in SMR can be attributed to factors such as diet, temperature, and body mass, yet much of the residual variation in SMR remains unexplained. Intuitively, we can expect SMR to co-vary with "personality", but the rapidly accumulating empirical evidence on this topic remains equivocal. The goal of this study was to test for a link between SMR and a behavioural syndrome at the among-individual level in wild-caught fall field crickets (Gryllus pennsylvanicus). Paired measurements of SMR and two behavioural traits were repeatedly taken over a two-month period, thus allowing to estimate the among-individual correlations (rind) separately from the residual (within-individual) correlations. The two behavioural traits (latency to exit a refuge in a novel environment and "freezing" time following a stressful stimulus) were significantly and moderately repeatable and were found to be part of a syndrome, as indicated by a strong and positive among-individual correlation (rind = 0.82 ± 0.27). Yet, only latency to exit was significantly and positively correlated with SMR (rind = 0.45 ± 0.21), suggesting that the link between boldness and SMR may be driven by individual differences in responses to novelty and not to simulated predatory cues. Since we found that bold individuals (short latency to exit) consistently had a lower SMR than shy individuals (long latency to exit), our results go against the pace-of-life syndrome hypothesis. Instead, our results suggest the presence of constrains in the energy budgets of crickets, which generated an allocation trade-off between energy spent on physical activity vs. maintenance costs (SMR).
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Affiliation(s)
- Vincent Careau
- Department of Biology, University of Ottawa, ON, Canada.
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26
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Studd EK, Landry‐Cuerrier M, Menzies AK, Boutin S, McAdam AG, Lane JE, Humphries MM. Behavioral classification of low-frequency acceleration and temperature data from a free-ranging small mammal. Ecol Evol 2019; 9:619-630. [PMID: 30680142 PMCID: PMC6342100 DOI: 10.1002/ece3.4786] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 10/10/2018] [Accepted: 10/31/2018] [Indexed: 01/03/2023] Open
Abstract
The miniaturization and affordability of new technology is driving a biologging revolution in wildlife ecology with use of animal-borne data logging devices. Among many new biologging technologies, accelerometers are emerging as key tools for continuously recording animal behavior. Yet a critical, but under-acknowledged consideration in biologging is the trade-off between sampling rate and sampling duration, created by battery- (or memory-) related sampling constraints. This is especially acute among small animals, causing most researchers to sample at high rates for very limited durations. Here, we show that high accuracy in behavioral classification is achievable when pairing low-frequency acceleration recordings with temperature. We conducted 84 hr of direct behavioral observations on 67 free-ranging red squirrels (200-300 g) that were fitted with accelerometers (2 g) recording tri-axial acceleration and temperature at 1 Hz. We then used a random forest algorithm and a manually created decision tree, with variable sampling window lengths, to associate observed behavior with logger recorded acceleration and temperature. Finally, we assessed the accuracy of these different classifications using an additional 60 hr of behavioral observations, not used in the initial classification. The accuracy of the manually created decision tree classification using observational data varied from 70.6% to 91.6% depending on the complexity of the tree, with increasing accuracy as complexity decreased. Short duration behavior like running had lower accuracy than long-duration behavior like feeding. The random forest algorithm offered similarly high overall accuracy, but the manual decision tree afforded the flexibility to create a hierarchical tree, and to adjust sampling window length for behavioral states with varying durations. Low frequency biologging of acceleration and temperature allows accurate behavioral classification of small animals over multi-month sampling durations. Nevertheless, low sampling rates impose several important limitations, especially related to assessing the classification accuracy of short duration behavior.
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Affiliation(s)
- Emily K. Studd
- Department of Natural Resource SciencesMcGill UniversitySainte‐Anne‐de‐BellevueQuebecCanada
| | | | - Allyson K. Menzies
- Department of Natural Resource SciencesMcGill UniversitySainte‐Anne‐de‐BellevueQuebecCanada
| | - Stan Boutin
- Department of Biological SciencesUniversity of AlbertaEdmontonAlbertaCanada
| | - Andrew G. McAdam
- Department of Integrative BiologyUniversity of GuelphGuelphOntarioCanada
| | - Jeffrey E. Lane
- Department of BiologyUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| | - Murray M. Humphries
- Department of Natural Resource SciencesMcGill UniversitySainte‐Anne‐de‐BellevueQuebecCanada
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Buckley LB, Khaliq I, Swanson DL, Hof C. Does metabolism constrain bird and mammal ranges and predict shifts in response to climate change? Ecol Evol 2018; 8:12375-12385. [PMID: 30619552 PMCID: PMC6308872 DOI: 10.1002/ece3.4537] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/25/2018] [Accepted: 08/18/2018] [Indexed: 01/09/2023] Open
Abstract
Mechanistic approaches for predicting the ranges of endotherms are needed to forecast their responses to environmental change. We test whether physiological constraints on maximum metabolic rate and the factor by which endotherms can elevate their metabolism (metabolic expansibility) influence cold range limits for mammal and bird species. We examine metabolic expansibility at the cold range boundary (MECRB) and whether species' traits can predict variability in MECRB and then use MECRB as an initial approach to project range shifts for 210 mammal and 61 bird species. We find evidence for metabolic constraints: the distributions of metabolic expansibility at the cold range boundary peak at similar values for birds (2.7) and mammals (3.2). The right skewed distributions suggest some species have adapted to elevate or evade metabolic constraints. Mammals exhibit greater skew than birds, consistent with their diverse thermoregulatory adaptations and behaviors. Mammal and bird species that are small and occupy low trophic levels exhibit high levels of MECRB. Mammals with high MECRB tend to hibernate or use torpor. Predicted metabolic rates at the cold range boundaries represent large energetic expenditures (>50% of maximum metabolic rates). We project species to shift their cold range boundaries poleward by an average of 3.9° latitude by 2070 if metabolic constraints remain constant. Our analysis suggests that metabolic constraints provide a viable mechanism for initial projections of the cold range boundaries for endotherms. However, errors and approximations in estimating metabolic constraints (e.g., acclimation responses) and evasion of these constraints (e.g., torpor/hibernation, microclimate selection) highlight the need for more detailed, taxa-specific mechanistic models. Even coarse considerations of metabolism will likely lead to improved predictions over exclusively considering thermal tolerance for endotherms.
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Affiliation(s)
| | - Imran Khaliq
- Zoology DepartmentGhazi UniversityPunjabPakistan
| | - David L. Swanson
- Department of BiologyUniversity of South DakotaVermillionSouth Dakota
| | - Christian Hof
- Terrestrial Ecology Research GroupDepartment of Ecology and Ecosystem ManagementSchool of Life Sciences WeihenstephanTechnical University of MunichFreisingGermany
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Rimbach R, Jäger J, Pillay N, Schradin C. Food Availability Is the Main Driver of Seasonal Changes in Resting Metabolic Rate in African Striped Mice (Rhabdomys pumilio). Physiol Biochem Zool 2018; 91:826-833. [PMID: 29381108 DOI: 10.1086/696828] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Resting metabolic rate (RMR) influences energy allocation to survival, growth, and reproduction, and significant seasonal changes in RMR have been reported. According to one hypothesis, seasonal changes in RMR are mainly attributable to seasonal changes in ambient temperature (Ta) and food availability. Studies on species from the temperate zone indicated that food availability is the main driver. However, whether this is generally true is unknown, because studies from the tropics and subtropics, where most species live, are rare. We studied the African striped mouse (Rhabdomys pumilio) inhabiting a seasonal environment with hot dry seasons with low food availability and cold moist seasons with high food availability. Using 603 RMR measurements of 277 individuals, we investigated the relative importance of food availability and Ta on RMR during selected periods, in which one extrinsic factor varied while the other factor was relatively constant. At similar Ta, residual RMR increased with increasing levels of food availability. In contrast, different Ta did not influence residual RMR at similar levels of food availability. Thus, our study on a subtropical species gives support to the hypothesis, derived from temperate zone species, that food availability mainly drives seasonal changes in RMR.
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Turner JM, Reher S, Warnecke L, Dausmann KH. Eurasian Red Squirrels Show Little Seasonal Variation in Metabolism in Food-Enriched Habitat. Physiol Biochem Zool 2017; 90:655-662. [DOI: 10.1086/694847] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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30
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Humphries MM, Studd EK, Menzies AK, Boutin S. To Everything There Is a Season: Summer-to-Winter Food Webs and the Functional Traits of Keystone Species. Integr Comp Biol 2017; 57:961-976. [DOI: 10.1093/icb/icx119] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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31
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Seasonal changes in energy expenditure, body temperature and activity patterns in llamas (Lama glama). Sci Rep 2017; 7:7600. [PMID: 28790450 PMCID: PMC5548813 DOI: 10.1038/s41598-017-07946-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 07/05/2017] [Indexed: 11/08/2022] Open
Abstract
Mammals typically keep their body temperature (Tb) within a narrow limit with changing environmental conditions. There are indications that some wild ungulates can exhibit certain forms of energy saving mechanisms when ambient temperatures are low and/or food is scarce. Therefore, the aim of the study was to determine if the llama, one of the most extensively kept domestic livestock species, exhibits seasonal adjustment mechanisms in terms of energy expenditure, Tb and locomotion. For that purpose llamas (N = 7) were kept in a temperate habitat on pasture. Locomotor activity, Tb (measured in the rumen) and the location of each animal were recorded continuously for one year using a telemetry system. Daily energy expenditure was measured as field metabolic rate (FMR). FMR fluctuated considerably between seasons with the lowest values found in winter (17.48 ± 3.98 MJ d−1, 402 kJ kg−0.75 d−1) and the highest in summer (25.87 ± 3.88 MJ d−1, 586 kJ kg−0.75 d−1). Llamas adjusted their energy expenditure, Tb and locomotor activity according to season and also time of day. Thus, llamas seem to have maintained the ability to reduce their energy expenditure and adjust their Tb under adverse environmental conditions as has been reported for some wild ungulates.
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32
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Gigliotti L, Diefenbach D, Sheriff M. Geographic variation in winter adaptations of snowshoe hares (Lepus americanus). CAN J ZOOL 2017. [DOI: 10.1139/cjz-2016-0165] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Understanding adaptations of nonhibernating northern endotherms to cope with extreme cold is important because climate-induced changes in winter temperatures and snow cover are predicted to impact these species the most. We compared winter pelage characteristics and heat production of snowshoe hares (Lepus americanus Erxleben, 1777) on the southern edge of their range, in Pennsylvania (USA), to a northern population, in the Yukon (Canada), to investigate how hares might respond to changing environmental conditions. We also investigated how hares in Pennsylvania altered movement rates and resting spot selection to cope with variable winter temperatures. Hares from Pennsylvania had shorter, less dense, and less white winter coats than their northern counterparts, suggesting lower coat insulation. Hares in the southern population had lower pelage temperatures, indicating that they produced less heat than those in the northern population. In addition, hares in Pennsylvania did not select for resting spots that offered thermal advantages, but selected locations offering visual obstruction from predators. Movement rates were associated with ambient temperature, with the smallest movements occurring at the lower and upper range of observed ambient temperatures. Our results indicate that snowshoe hares may be able to adapt to future climate conditions via changes in pelage characteristics, metabolism, and behavior.
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Affiliation(s)
- L.C. Gigliotti
- Pennsylvania Cooperative Fish and Wildlife Research Unit, The Pennsylvania State University, University Park, PA 16802, USA
| | - D.R. Diefenbach
- U.S. Geological Survey, Pennsylvania Cooperative Fish and Wildlife Research Unit, The Pennsylvania State University, University Park, PA 16802, USA
| | - M.J. Sheriff
- Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA 16802, USA
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33
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Theimer TC, Williams CT, Johnson SR, Gilbert AT, Bergman DL, Buck CL. Den use and heterothermy during winter in free-living, suburban striped skunks. J Mammal 2017. [DOI: 10.1093/jmammal/gyx009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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34
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Levesque DL, Nowack J, Stawski C. Modelling mammalian energetics: the heterothermy problem. ACTA ACUST UNITED AC 2016. [DOI: 10.1186/s40665-016-0022-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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35
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Portugal SJ, Green JA, Halsey LG, Arnold W, Careau V, Dann P, Frappell PB, Grémillet D, Handrich Y, Martin GR, Ruf T, Guillemette MM, Butler PJ. Associations between Resting, Activity, and Daily Metabolic Rate in Free-Living Endotherms: No Universal Rule in Birds and Mammals. Physiol Biochem Zool 2016; 89:251-61. [PMID: 27153134 DOI: 10.1086/686322] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Energy management models provide theories and predictions for how animals manage their energy budgets within their energetic constraints, in terms of their resting metabolic rate (RMR) and daily energy expenditure (DEE). Thus, uncovering what associations exist between DEE and RMR is key to testing these models. Accordingly, there is considerable interest in the relationship between DEE and RMR at both inter- and intraspecific levels. Interpretation of the evidence for particular energy management models is enhanced by also considering the energy spent specifically on costly activities (activity energy expenditure [AEE] = DEE - RMR). However, to date there have been few intraspecific studies investigating such patterns. Our aim was to determine whether there is a generality of intraspecific relationships among RMR, DEE, and AEE using long-term data sets for bird and mammal species. For mammals, we use minimum heart rate (fH), mean fH, and activity fH as qualitative proxies for RMR, DEE, and AEE, respectively. For the birds, we take advantage of calibration equations to convert fH into rate of oxygen consumption in order to provide quantitative proxies for RMR, DEE, and AEE. For all 11 species, the DEE proxy was significantly positively correlated with the RMR proxy. There was also evidence of a significant positive correlation between AEE and RMR in all four mammal species but only in some of the bird species. Our results indicate there is no universal rule for birds and mammals governing the relationships among RMR, AEE, and DEE. Furthermore, they suggest that birds tend to have a different strategy for managing their energy budgets from those of mammals and that there are also differences in strategy between bird species. Future work in laboratory settings or highly controlled field settings can tease out the environmental and physiological processes contributing to variation in energy management strategies exhibited by different species.
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36
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Studd EK, Boutin S, McAdam AG, Humphries MM. Nest attendance of lactating red squirrels (Tamiasciurus hudsonicus): influences of biological and environmental correlates. J Mammal 2016. [DOI: 10.1093/jmammal/gyw010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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37
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Ellsworth E, Boudreau M, Nagy K, Rachlow J, Murray D. Differential sex-related winter energetics in free-ranging snowshoe hares ( Lepus americanus). CAN J ZOOL 2016. [DOI: 10.1139/cjz-2015-0074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Animals spend considerable time and energy acquiring food to meet their metabolic requirements, but if energetic or fitness costs are substantive, such as during winter, then some individuals may limit daily energy expenditure by reducing foraging duration. To date, the prevalence and magnitude of such compensatory foraging responses are poorly known. We examined energy balance compensation in free-ranging snowshoe hares (Lepus americanus Erxleben, 1777) via a food supplementation experiment to determine whether individuals reduced their daily energy expenditure (DEE) and activity periods in response to increased food availability. Overall, food supplementation had no effect on diel activity patterns, although males had higher DEE compared with females. During early and mid-winter, hares did not alter their activity periods in response to food supplementation, but during late winter, when natural food availability declined, food-supplemented females (but not males) were ∼11% less active compared with controls. Natural food likely was sufficient and could have been acquired at relatively low energetic cost, but because males likely have higher DEE due to mating behavior whereas females may limit their activity (and thus DEE) to reduce predation risk, we conclude that gender-specific life-history demands can over-ride predicted responses to supplemental food when baseline food abundance is adequate.
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Affiliation(s)
- E. Ellsworth
- Department of Fish and Wildlife Sciences, University of Idaho, 875 Perimeter Drive, MS 1136, Moscow, ID 83843-1136, USA
| | - M.R. Boudreau
- Department of Biology, Trent University, Peterborough, ON K97 7B8, Canada
| | - K. Nagy
- Department of Ecology and Evolutionary Biology, University of California, 621 Young Drive South, Los Angeles, CA 90095-1606, USA
| | - J.L. Rachlow
- Department of Fish and Wildlife Sciences, University of Idaho, 875 Perimeter Drive, MS 1136, Moscow, ID 83843-1136, USA
| | - D.L. Murray
- Department of Biology, Trent University, Peterborough, ON K97 7B8, Canada
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38
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Brinkmann L, Gerken M, Hambly C, Speakman JR, Riek A. Thyroid hormones correlate with field metabolic rate in ponies, Equus ferus caballus. J Exp Biol 2016; 219:2559-66. [DOI: 10.1242/jeb.138784] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 06/02/2016] [Indexed: 01/08/2023]
Abstract
During winter free living herbivores are often exposed to reduced energy supply at the same time that energy needs for thermoregulation increase. Several wild herbivores as well as robust horse breeds reduce their metabolism during times of low ambient temperature and food shortage. Thyroid hormones (TH) affect metabolic intensity and a positive effect of TH on basal metabolic rate (BMR) has been demonstrated in mammals and birds. As BMR and field metabolic rate (FMR) are often assumed to be intrinsically linked, TH may represent a reliable indicator for FMR. To test this hypothesis, ten Shetland pony mares were kept under semi-extensive central European conditions. During the winter month one group was fed 60% and one group 100% of their maintenance energy requirements. We measured FMR, locomotor activity, resting heart rate and TH levels in summer and winter. FMR, locomotor activity, resting heart rate and total T3 concentrations decreased substantially in winter compared to summer, whereas total T4 increased. Feed restriction led to a reduced FMR and resting heart rate, while TH and locomotor activity were not affected. Across both seasons FMR, resting heart and locomotor activity were positively correlated with total T3 but negatively and more weakly related with total T4.
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Affiliation(s)
- Lea Brinkmann
- Department of Animal Sciences, University of Göttingen, 37075 Göttingen, Germany
| | - Martina Gerken
- Department of Animal Sciences, University of Göttingen, 37075 Göttingen, Germany
| | - Catherine Hambly
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - John R. Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
- Institute of Genetics and Developmental Biology, State Key Laboratory of Molecular Developmental Biology, Chinese Academy of Sciences, 100101 Beijing, PR China
| | - Alexander Riek
- Department of Animal Sciences, University of Göttingen, 37075 Göttingen, Germany
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39
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Brigham RM, Geiser F. Do red squirrels (Tamiasciurus hudsonicus) use daily torpor during winter? ECOSCIENCE 2015. [DOI: 10.2980/19-2-3464] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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40
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Mabille G, Berteaux D, Thomas DW, Fortin D. Behavioural responses of wintering porcupines to their heterogeneous thermal environment. ECOSCIENCE 2015. [DOI: 10.2980/18-4-3413] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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41
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Uchida K, Suzuki K, Shimamoto T, Yanagawa H, Koizumi I. Seasonal variation of flight initiation distance in Eurasian red squirrels in urban versus rural habitat. J Zool (1987) 2015. [DOI: 10.1111/jzo.12306] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- K. Uchida
- Graduate School of Environmental Science; Hokkaido University; Sapporo Japan
| | - K. Suzuki
- Laboratory of Wildlife Ecology; Obihiro University of Agriculture and Veterinary Medicine; Obihiro Japan
| | - T. Shimamoto
- Laboratory of Wildlife Ecology; Obihiro University of Agriculture and Veterinary Medicine; Obihiro Japan
- The United Graduate School of Agricultural Sciences; Iwate University; Morioka Japan
| | - H. Yanagawa
- Laboratory of Wildlife Ecology; Obihiro University of Agriculture and Veterinary Medicine; Obihiro Japan
| | - I. Koizumi
- Graduate School of Environmental Science; Hokkaido University; Sapporo Japan
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42
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Rezende EL, Bacigalupe LD. Thermoregulation in endotherms: physiological principles and ecological consequences. J Comp Physiol B 2015; 185:709-27. [PMID: 26025431 DOI: 10.1007/s00360-015-0909-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 04/18/2015] [Accepted: 04/27/2015] [Indexed: 01/01/2023]
Abstract
In a seminal study published nearly 70 years ago, Scholander et al. (Biol Bull 99:259-271, 1950) employed Newton's law of cooling to describe how metabolic rates (MR) in birds and mammals vary predictably with ambient temperature (T a). Here, we explore the theoretical consequences of Newton's law of cooling and show that a thermoregulatory polygon provides an intuitively simple and yet useful description of thermoregulatory responses in endothermic organisms. This polygon encapsulates the region in which heat production and dissipation are in equilibrium and, therefore, the range of conditions in which thermoregulation is possible. Whereas the typical U-shaped curve describes the relationship between T a and MR at rest, thermoregulatory polygons expand this framework to incorporate the impact of activity, other behaviors and environmental conditions on thermoregulation and energy balance. We discuss how this framework can be employed to study the limits to effective thermoregulation and their ecological repercussions, allometric effects and residual variation in MR and thermal insulation, and how thermoregulatory requirements might constrain locomotor or reproductive performance (as proposed, for instance, by the heat dissipation limit theory). In many systems the limited empirical knowledge on how organismal traits may respond to environmental changes prevents physiological ecology from becoming a fully developed predictive science. In endotherms, however, we contend that the lack of theoretical developments that translate current physiological understanding into formal mechanistic models remains the main impediment to study the ecological and evolutionary repercussions of thermoregulation. In spite of the inherent limitations of Newton's law of cooling as an oversimplified description of the mechanics of heat transfer, we argue that understanding how systems that obey this approximation work can be enlightening on conceptual grounds and relevant as an analytical and predictive tool to study ecological phenomena. As such, the proposed approach may constitute a powerful tool to study the impact of thermoregulatory constraints on variables related to fitness, such as survival and reproductive output, and help elucidating how species will be affected by ongoing climate change.
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Affiliation(s)
- Enrico L Rezende
- Department of Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, UK.
| | - Leonardo D Bacigalupe
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile.
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43
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Cliffe RN, Haupt RJ, Avey-Arroyo JA, Wilson RP. Sloths like it hot: ambient temperature modulates food intake in the brown-throated sloth (Bradypus variegatus). PeerJ 2015; 3:e875. [PMID: 25861559 PMCID: PMC4389270 DOI: 10.7717/peerj.875] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 03/12/2015] [Indexed: 11/20/2022] Open
Abstract
Sloths are considered to have one of the lowest mass-specific metabolic rates of any mammal and, in tandem with a slow digestive rate, have been theorized to have correspondingly low rates of ingestion. Here, we show in a study conducted over five months, that three captive Bradypus variegatus (Brown-throated sloths) had a remarkably low mean food intake of 17 g kg(-1)day(-1) (SD 4.2). Food consumption was significantly affected by ambient temperature, with increased intake at higher temperatures. We suggest that the known fluctuation of sloth core body temperature with ambient temperature affects the rate at which gut fauna process digesta, allowing for increased rates of fermentation at higher temperatures. Since Bradypus sloths maintain a constantly full stomach, faster rates of fermentation should enhance digestive throughput, increasing the capacity for higher levels of food intake, thereby allowing increased energy acquisition at higher ambient temperatures. This contrasts with other mammals, which tend to show increased levels of food intake in colder conditions, and points to the importance of temperature in regulating all aspects of energy use in sloths.
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Affiliation(s)
- Rebecca N. Cliffe
- Swansea Lab for Animal Movement, Biosciences, College of Science, Swansea University, Swansea, Wales, United Kingdom
- The Sloth Sanctuary of Costa Rica, Limon, Costa Rica, Central America
| | - Ryan J. Haupt
- Department of Geology and Geophysics, University of Wyoming, Laramie, WY, United States
| | | | - Rory P. Wilson
- Swansea Lab for Animal Movement, Biosciences, College of Science, Swansea University, Swansea, Wales, United Kingdom
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44
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Cortés PA, Petit M, Lewden A, Milbergue M, Vézina F. Individual inconsistencies in basal and summit metabolic rate highlight flexibility of metabolic performance in a wintering passerine. ACTA ACUST UNITED AC 2015; 323:179-90. [DOI: 10.1002/jez.1908] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 11/12/2014] [Accepted: 11/13/2014] [Indexed: 01/22/2023]
Affiliation(s)
- Pablo Andrés Cortés
- Instituto de Ciencias Ambientales y; Facultad de Ciencias; Universidad Austral de Chile Campus Isla Teja; Valdivia Chile
| | - Magali Petit
- Département de biologie; chimie et géographie; Université du Québec à Rimouski; Rimouski Canada
- Groupe de recherche sur les environnements nordiques BORÉAS; Rimouski Canada
- Centre d'Etudes Nordiques; Québec Canada
- Centre de la Science de la Biodiversité du Québec; Montréal Canada
| | - Agnès Lewden
- Département de biologie; chimie et géographie; Université du Québec à Rimouski; Rimouski Canada
- Groupe de recherche sur les environnements nordiques BORÉAS; Rimouski Canada
| | - Myriam Milbergue
- Département de biologie; chimie et géographie; Université du Québec à Rimouski; Rimouski Canada
- Groupe de recherche sur les environnements nordiques BORÉAS; Rimouski Canada
- Centre d'Etudes Nordiques; Québec Canada
- Centre de la Science de la Biodiversité du Québec; Montréal Canada
| | - François Vézina
- Département de biologie; chimie et géographie; Université du Québec à Rimouski; Rimouski Canada
- Groupe de recherche sur les environnements nordiques BORÉAS; Rimouski Canada
- Centre d'Etudes Nordiques; Québec Canada
- Centre de la Science de la Biodiversité du Québec; Montréal Canada
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45
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White CR, Kearney MR. Metabolic scaling in animals: methods, empirical results, and theoretical explanations. Compr Physiol 2014; 4:231-56. [PMID: 24692144 DOI: 10.1002/cphy.c110049] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Life on earth spans a size range of around 21 orders of magnitude across species and can span a range of more than 6 orders of magnitude within species of animal. The effect of size on physiology is, therefore, enormous and is typically expressed by how physiological phenomena scale with mass(b). When b ≠ 1 a trait does not vary in direct proportion to mass and is said to scale allometrically. The study of allometric scaling goes back to at least the time of Galileo Galilei, and published scaling relationships are now available for hundreds of traits. Here, the methods of scaling analysis are reviewed, using examples for a range of traits with an emphasis on those related to metabolism in animals. Where necessary, new relationships have been generated from published data using modern phylogenetically informed techniques. During recent decades one of the most controversial scaling relationships has been that between metabolic rate and body mass and a number of explanations have been proposed for the scaling of this trait. Examples of these mechanistic explanations for metabolic scaling are reviewed, and suggestions made for comparing between them. Finally, the conceptual links between metabolic scaling and ecological patterns are examined, emphasizing the distinction between (1) the hypothesis that size- and temperature-dependent variation among species and individuals in metabolic rate influences ecological processes at levels of organization from individuals to the biosphere and (2) mechanistic explanations for metabolic rate that may explain the size- and temperature-dependence of this trait.
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Affiliation(s)
- Craig R White
- School of Biological Sciences, The University of Queensland, St Lucia, Queensland, Australia
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46
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Brinkmann L, Gerken M, Hambly C, Speakman JR, Riek A. Saving energy during hard times: energetic adaptations of Shetland pony mares. ACTA ACUST UNITED AC 2014; 217:4320-7. [PMID: 25359931 DOI: 10.1242/jeb.111815] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Recent results suggest that wild Northern herbivores reduce their metabolism during times of low ambient temperature and food shortage in order to reduce their energetic needs. It is, however, not known whether domesticated animals are also able to reduce their energy expenditure. We exposed 10 Shetland pony mares to different environmental conditions (summer and winter) and to two food quantities (60% and 100% of maintenance energy requirement) during low winter temperatures to examine energetic and behavioural responses. In summer, ponies showed a considerably higher field metabolic rate (FMR; 63.4±15.0 MJ day(-1)) compared with food-restricted and control animals in winter (24.6±7.8 and 15.0±1.1 MJ day(-1), respectively). During summer, locomotor activity, resting heart rate and total water turnover were considerably elevated (P<0.001) compared with winter. Animals on a restricted diet (N=5) compensated for the decreased energy supply by reducing their FMR by 26% compared with control animals (N=5). Furthermore, resting heart rate, body mass and body condition score were lower (29.2±2.7 beats min(-1), 140±22 kg and 3.0±1.0 points, respectively) than in control animals (36.8±41 beats min(-1), 165±31 kg, 4.4±0.7 points; P<0.05). While the observed behaviour did not change, nocturnal hypothermia was elevated. We conclude that ponies acclimatize to different climatic conditions by changing their metabolic rate, behaviour and some physiological parameters. When exposed to energy challenges, ponies, like wild herbivores, exhibited hypometabolism and nocturnal hypothermia.
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Affiliation(s)
- Lea Brinkmann
- Department of Animal Sciences, University of Göttingen, D-37075 Göttingen, Germany
| | - Martina Gerken
- Department of Animal Sciences, University of Göttingen, D-37075 Göttingen, Germany
| | - Catherine Hambly
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - John R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK. Institute of Genetics and Developmental Biology, State Key Laboratory of Molecular Developmental Biology, Chinese Academy of Sciences, 100101 Beijing, PR China
| | - Alexander Riek
- Department of Animal Sciences, University of Göttingen, D-37075 Göttingen, Germany.
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Cortés PA, Franco M, Moreno-Gómez FN, Barrientos K, Nespolo RF. Thermoregulatory capacities and torpor in the South American marsupial, Dromiciops gliroides. J Therm Biol 2014; 45:1-8. [DOI: 10.1016/j.jtherbio.2014.07.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 07/03/2014] [Accepted: 07/03/2014] [Indexed: 10/25/2022]
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Fletcher QE, Speakman JR, Boutin S, Lane JE, McAdam AG, Gorrell JC, Coltman DW, Humphries MM. Daily energy expenditure during lactation is strongly selected in a free‐living mammal. Funct Ecol 2014. [DOI: 10.1111/1365-2435.12313] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Quinn E. Fletcher
- Department of Natural Resource Sciences Macdonald Campus McGill University Ste‐Anne‐de‐Bellevue QuebecH9X 3V9 Canada
| | - John R. Speakman
- Institute of Biological and Environmental Sciences University of Aberdeen AberdeenAB24 2TZ UK
- State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental Biology 1 West Beichen RoadChaoyang Beijing 100080 China
| | - Stan Boutin
- Department of Biological Sciences University of Alberta Edmonton AlbertaT6G 2E9 Canada
| | - Jeffrey E. Lane
- Department of Biological Sciences University of Alberta Edmonton AlbertaT6G 2E9 Canada
| | - Andrew G. McAdam
- Department of Integrative Biology University of Guelph Guelph Ontario N1G 2W1 Canada
| | - Jamieson C. Gorrell
- Department of Biological Sciences University of Alberta Edmonton AlbertaT6G 2E9 Canada
| | - David W. Coltman
- Department of Biological Sciences University of Alberta Edmonton AlbertaT6G 2E9 Canada
| | - Murray M. Humphries
- Department of Natural Resource Sciences Macdonald Campus McGill University Ste‐Anne‐de‐Bellevue QuebecH9X 3V9 Canada
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Genoud M. Thermal energetics of the New-Guinean moss-forest rat (Rattus niobe) in comparison with other tropical murid rodents. J Therm Biol 2014; 41:95-103. [DOI: 10.1016/j.jtherbio.2014.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 12/29/2013] [Accepted: 01/14/2014] [Indexed: 11/28/2022]
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50
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Tomlinson S, Withers PC, Maloney SK. Huddling behaviour and energetics of Sminthopsis spp. (Marsupialia, Dasyruidae) in response to environmental challenge. Physiol Behav 2014; 128:9-15. [DOI: 10.1016/j.physbeh.2014.01.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 01/24/2014] [Accepted: 01/26/2014] [Indexed: 11/28/2022]
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