1
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Blanco MB, Smith DL, Greene LK, Yoder AD, Ehmke EE, Lin J, Klopfer PH. Telomere dynamics during hibernation in a tropical primate. J Comp Physiol B 2024; 194:213-219. [PMID: 38466418 DOI: 10.1007/s00360-024-01541-9] [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: 09/12/2023] [Revised: 01/13/2024] [Accepted: 01/23/2024] [Indexed: 03/13/2024]
Abstract
Hibernation is a widespread metabolic strategy among mammals for surviving periods of food scarcity. During hibernation, animals naturally alternate between metabolically depressed torpor bouts and energetically expensive arousals without ill effects. As a result, hibernators are promising models for investigating mechanisms that buffer against cellular stress, including telomere protection and restoration. In non-hibernators, telomeres, the protective structural ends of chromosomes, shorten with age and metabolic stress. In temperate hibernators, however, telomere shortening and elongation can occur in response to changing environmental conditions and associated metabolic state. We investigate telomere dynamics in a tropical hibernating primate, the fat-tailed dwarf lemur (Cheirogaleus medius). In captivity, these lemurs can hibernate when maintained under cold temperatures (11-15 °C) with limited food provisioning. We study telomere dynamics in eight fat-tailed dwarf lemurs at the Duke Lemur Center, USA, from samples collected before, during, and after the hibernation season and assayed via qPCR. Contrary to our predictions, we found that telomeres were maintained or even lengthened during hibernation, but shortened immediately thereafter. During hibernation, telomere lengthening was negatively correlated with time in euthermia. Although preliminary in scope, our findings suggest that there may be a preemptive, compensatory mechanism to maintain telomere integrity in dwarf lemurs during hibernation. Nevertheless, telomere shortening immediately afterward may broadly result in similar outcomes across seasons. Future studies could profitably investigate the mechanisms that offset telomere shortening within and outside of the hibernation season and whether those mechanisms are modulated by energy surplus or crises.
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Affiliation(s)
- M B Blanco
- Duke Lemur Center, Durham, NC, 27705, USA.
- Department of Biology, Duke University, Durham, NC, 27708, USA.
| | - D L Smith
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, 94143, USA
| | - L K Greene
- Duke Lemur Center, Durham, NC, 27705, USA
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - A D Yoder
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - E E Ehmke
- Duke Lemur Center, Durham, NC, 27705, USA
| | - J Lin
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, 94143, USA
| | - P H Klopfer
- Department of Biology, Duke University, Durham, NC, 27708, USA
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2
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Levesque DL, Breit AM, Brown E, Nowack J, Welman S. Non-Torpid Heterothermy in Mammals: Another Category along the Homeothermy-Hibernation Continuum. Integr Comp Biol 2023; 63:1039-1048. [PMID: 37407285 DOI: 10.1093/icb/icad094] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 06/14/2023] [Accepted: 06/29/2023] [Indexed: 07/07/2023] Open
Abstract
Variability in body temperature is now recognized to be widespread among whole-body endotherms with homeothermy being the exception rather than the norm. A wide range of body temperature patterns exists in extant endotherms, spanning from strict homeothermy, to occasional use of torpor, to deep seasonal hibernation with many points in between. What is often lost in discussions of heterothermy in endotherms are the benefits of variations in body temperature outside of torpor. Endotherms that do not use torpor can still obtain extensive energy and water savings from varying levels of flexibility in normothermic body temperature regulation. Flexibility at higher temperatures (heat storage or facultative hyperthermia) can provide significant water savings, while decreases at cooler temperatures, even outside of torpor, can lower the energetic costs of thermoregulation during rest. We discuss the varying uses of the terms heterothermy, thermolability, and torpor to describe differences in the amplitude of body temperature cycles and advocate for a broader use of the term "heterothermy" to include non-torpid variations in body temperature.
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Affiliation(s)
| | - Ana M Breit
- School of Biology and Ecology, University of Maine, 04469 Orono, ME, USA
| | - Eric Brown
- School of Biology and Ecology, University of Maine, 04469 Orono, ME, USA
| | - Julia Nowack
- School of Biological and Environmental Sciences, Liverpool John Moores University, L3 3AF Liverpool, UK
| | - Shaun Welman
- Department of Zoology, Nelson Mandela University, Gqeberha 6031, South Africa
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3
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Nowack J, Mzilikazi N, Dausmann KH. Saving energy via short and shallow torpor bouts. J Therm Biol 2023; 114:103572. [PMID: 37344030 DOI: 10.1016/j.jtherbio.2023.103572] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/04/2023] [Accepted: 04/05/2023] [Indexed: 06/23/2023]
Abstract
Maintaining a high and stable body temperature as observed in most endothermic mammals and birds is energetically costly and many heterothermic species reduce their metabolic demands during energetic bottlenecks through the use of torpor. With the increasing number of heterotherms revealed in a diversity of habitats, it becomes apparent that triggers and patterns of torpor use are more variable than previously thought. Here, we report the previously overlooked use of, shallow rest-time torpor (body temperature >30 °C) in African lesser bushbabies, Galago moholi. Body core temperature of three adult male bushbabies recorded over five months showed a clear bimodal distribution with an average active modal temperature of 39.2 °C and a resting modal body temperature of 36.7 °C. Shallow torpor was observed in two out of three males (n = 29 torpor bouts) between June and August (austral winter), with body temperatures dropping to an overall minimum of 30.7 °C and calculated energy savings of up to 10%. We suggest that shallow torpor may be an ecologically important, yet mostly overlooked energy-saving strategy employed by heterothermic mammals. Our data emphasise that torpor threshold temperatures need to be used with care if we aim to fully understand the level of physiological plasticity displayed by heterothermic species.
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Affiliation(s)
- Julia Nowack
- School of Biological and Environmental Sciences, Liverpool John Moores University, Byrom Street, Liverpool, United Kingdom; Department of Biology, Institute of Cell and Systems Biology of Animals, Functional Ecology, University Hamburg, Hamburg, Germany.
| | - Nomakwezi Mzilikazi
- Department of Zoology, Nelson Mandela University, Port Elizabeth, South Africa
| | - Kathrin H Dausmann
- Department of Biology, Institute of Cell and Systems Biology of Animals, Functional Ecology, University Hamburg, Hamburg, Germany
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4
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Hending D, Randrianarison H, Andriamavosoloarisoa NNM, Ranohatra-Hending C, Solofondranohatra JS, Tongasoa HR, Ranarison HT, Gehrke V, Andrianirina N, Holderied M, McCabe G, Cotton S. Seasonal Differences in the Encounter Rate of the Fat-Tailed Dwarf Lemur (Cheirogaleus medius) in the Transitional Forests of Northwest Madagascar: Implications for Reliable Population Density Assessment. INT J PRIMATOL 2023. [DOI: 10.1007/s10764-023-00353-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Abstract
Primate encounter rates often vary throughout the year due to seasonal differences in activity, ecology, and behaviour. One notably extreme behaviour is continuous hibernation. Although a rare adaptation in primates, the dwarf lemurs of Madagascar (genus Cheirogaleus) enter obligate hibernation each year during the dry season, after spending the wet season consuming high-energy foods. Whilst seasonal changes in activity in some Cheirogaleus populations are well-known, many species remain little-studied, and there is no specific information on their encounter rates, nor when they enter and emerge from hibernation. This uncertainty critically affects reliable calculation of population density estimates for these highly threatened lemurs. In this study, we assessed how encounter rates of the fat-tailed dwarf lemur (C. medius) vary seasonally in the transitional forests of the Sahamalaza-Iles Radama National Park, northwest Madagascar, during a 4-year period. We established a system of line transects (N = 60) throughout our study area, on which we conducted distance sampling of C. medius. We then used our distance sampling data to calculate encounter rate and population density data. We found encounter rates of C. medius to be significantly higher during the wet season compared with the dry season. Furthermore, encounter rates of C. medius were particularly low from May–August. These results provide some evidence to suggest the time period that C. medius hibernate in Sahamalaza-Iles Radama National Park. These findings underpin the importance of careful study design when surveying threatened species with seasonal differences in activity, such as those that hibernate. This study also demonstrates the importance of species-specific behavioural data for accurate population density assessment, which is required to inform conservation action.
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5
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Henke‐von der Malsburg J, Fichtel C, Kappeler PM. Retaining memory after hibernation: Performance varies independently of activity levels in wild grey mouse lemurs. Ethology 2022. [DOI: 10.1111/eth.13337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Johanna Henke‐von der Malsburg
- Behavioral Ecology and Sociobiology Unit German Primate Center, Leibniz Institute for Primatology Göttingen Germany
- Leibniz ScienceCampus ‘Primate Cognition’ Göttingen Germany
- Department of Sociobiology/Anthropology Johann‐Friedrich‐Blumenbach Institute of Zoology and Anthropology, Kellnerweg 6, 37077 Göttingen, Georg‐August‐University Göttingen Göttingen Germany
- Technological Primates Research Group Max‐Planck Institute for Evolutionary Anthropology Leipzig Germany
| | - Claudia Fichtel
- Behavioral Ecology and Sociobiology Unit German Primate Center, Leibniz Institute for Primatology Göttingen Germany
- Leibniz ScienceCampus ‘Primate Cognition’ Göttingen Germany
| | - Peter M. Kappeler
- Behavioral Ecology and Sociobiology Unit German Primate Center, Leibniz Institute for Primatology Göttingen Germany
- Department of Sociobiology/Anthropology Johann‐Friedrich‐Blumenbach Institute of Zoology and Anthropology, Kellnerweg 6, 37077 Göttingen, Georg‐August‐University Göttingen Göttingen Germany
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6
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Nowack J, Turbill C. Survivable hypothermia or torpor in a wild-living rat: rare insights broaden our understanding of endothermic physiology. J Comp Physiol B 2021; 192:183-192. [PMID: 34668054 PMCID: PMC8817056 DOI: 10.1007/s00360-021-01416-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 09/08/2021] [Accepted: 10/03/2021] [Indexed: 12/16/2022]
Abstract
Maintaining a high and stable body temperature as observed in endothermic mammals and birds is energetically costly. Thus, it is not surprising that we discover more and more heterothermic species that can reduce their energetic needs during energetic bottlenecks through the use of torpor. However, not all heterothermic animals use torpor on a regular basis. Torpor may also be important to an individual’s probability of survival, and hence fitness, when used infrequently. We here report the observation of a single, ~ 5.5 h long hypothermic bout with a decrease in body temperature by 12 °C in the native Australian bush rat (Rattus fuscipes). Our data suggest that bush rats are able to rewarm from a body temperature of 24 °C, albeit with a rewarming rate lower than that expected on the basis of their body mass. Heterothermy, i.e. the ability to withstand and overcome periods of reduced body temperature, is assumed to be an evolutionarily ancestral (plesiomorphic) trait. We thus argue that such rare hypothermic events in species that otherwise appear to be strictly homeothermic could be heterothermic rudiments, i.e. a less derived form of torpor with limited capacity for rewarming. Importantly, observations of rare and extreme thermoregulatory responses by wild animals are more likely to be discovered with long-term data sets and may not only provide valuable insight about the physiological capability of a population, but can also help us to understand the constraints and evolutionary pathways of different phenologies.
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Affiliation(s)
- Julia Nowack
- Hawkesbury Institute for the Environment and School of Science, Western Sydney University, Richmond, NSW, Australia. .,School of Biological and Environmental Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK.
| | - Christopher Turbill
- Hawkesbury Institute for the Environment and School of Science, Western Sydney University, Richmond, NSW, Australia
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7
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Shi Z, Qin M, Huang L, Xu T, Chen Y, Hu Q, Peng S, Peng Z, Qu LN, Chen SG, Tuo QH, Liao DF, Wang XP, Wu RR, Yuan TF, Li YH, Liu XM. Human torpor: translating insights from nature into manned deep space expedition. Biol Rev Camb Philos Soc 2020; 96:642-672. [PMID: 33314677 DOI: 10.1111/brv.12671] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/09/2020] [Accepted: 11/17/2020] [Indexed: 12/12/2022]
Abstract
During a long-duration manned spaceflight mission, such as flying to Mars and beyond, all crew members will spend a long period in an independent spacecraft with closed-loop bioregenerative life-support systems. Saving resources and reducing medical risks, particularly in mental heath, are key technology gaps hampering human expedition into deep space. In the 1960s, several scientists proposed that an induced state of suppressed metabolism in humans, which mimics 'hibernation', could be an ideal solution to cope with many issues during spaceflight. In recent years, with the introduction of specific methods, it is becoming more feasible to induce an artificial hibernation-like state (synthetic torpor) in non-hibernating species. Natural torpor is a fascinating, yet enigmatic, physiological process in which metabolic rate (MR), body core temperature (Tb ) and behavioural activity are reduced to save energy during harsh seasonal conditions. It employs a complex central neural network to orchestrate a homeostatic state of hypometabolism, hypothermia and hypoactivity in response to environmental challenges. The anatomical and functional connections within the central nervous system (CNS) lie at the heart of controlling synthetic torpor. Although progress has been made, the precise mechanisms underlying the active regulation of the torpor-arousal transition, and their profound influence on neural function and behaviour, which are critical concerns for safe and reversible human torpor, remain poorly understood. In this review, we place particular emphasis on elaborating the central nervous mechanism orchestrating the torpor-arousal transition in both non-flying hibernating mammals and non-hibernating species, and aim to provide translational insights into long-duration manned spaceflight. In addition, identifying difficulties and challenges ahead will underscore important concerns in engineering synthetic torpor in humans. We believe that synthetic torpor may not be the only option for manned long-duration spaceflight, but it is the most achievable solution in the foreseeable future. Translating the available knowledge from natural torpor research will not only benefit manned spaceflight, but also many clinical settings attempting to manipulate energy metabolism and neurobehavioural functions.
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Affiliation(s)
- Zhe Shi
- National Clinical Research Center for Mental Disorders, and Department of Psychaitry, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China.,Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China.,State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China.,Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai, 200030, China
| | - Meng Qin
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Lu Huang
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, 510632, China
| | - Tao Xu
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China
| | - Ying Chen
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Qin Hu
- College of Life Sciences and Bio-Engineering, Beijing University of Technology, Beijing, 100024, China
| | - Sha Peng
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Zhuang Peng
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Li-Na Qu
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Shan-Guang Chen
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Qin-Hui Tuo
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Duan-Fang Liao
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Xiao-Ping Wang
- National Clinical Research Center for Mental Disorders, and Department of Psychaitry, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China
| | - Ren-Rong Wu
- National Clinical Research Center for Mental Disorders, and Department of Psychaitry, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China
| | - Ti-Fei Yuan
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai, 200030, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226000, China
| | - Ying-Hui Li
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Xin-Min Liu
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China.,State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China.,Research Center for Pharmacology and Toxicology, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
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8
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Altitudinal and Seasonal Variation in the Structure of Nocturnal Primate Assemblages on Mount Cameroon. INT J PRIMATOL 2020. [DOI: 10.1007/s10764-020-00179-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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9
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McFarland R, Barrett L, Fuller A, Hetem RS, Porter WP, Young C, Henzi SP. Infrared thermography cannot be used to approximate core body temperature in wild primates. Am J Primatol 2020; 82:e23204. [PMID: 33043502 DOI: 10.1002/ajp.23204] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 09/19/2020] [Accepted: 09/26/2020] [Indexed: 12/17/2022]
Abstract
Understanding the physiological processes that underpin primate performance is key if we are to assess how a primate might respond when navigating new and changing environments. Given the connection between a mammal's ability to thermoregulate and the changing demands of its thermal environment, increasing attention is being devoted to the study of thermoregulatory processes as a means to assess primate performance. Infrared thermography can be used to record the body surface temperatures of free-ranging animals. However, some uncertainty remains as to how these measurements can be used to approximate core body temperature. Here, we use data collected from wild vervet monkeys (Chlorocebus pygerythrus) to examine the relationship between infrared body surface temperature, core body (intra-abdominal) temperature, and local climate, to determine to what extent surface temperatures reflect core body temperature. While we report a positive association between surface and core body temperature-a finding that has previously been used to justify the use of surface temperature measurements as a proxy for core temperature regulation-when we controlled for the effect of the local climate in our analyses, this relationship was no longer observed. That is, body surface temperatures were solely predicted by local climate, and not core body temperatures, suggesting that surface temperatures tell us more about the environment a primate is in, and less about the thermal status of its body core in that environment. Despite the advantages of a noninvasive means to detect and record animal temperatures, infrared thermography alone cannot be used to approximate core body temperature in wild primates.
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Affiliation(s)
- Richard McFarland
- Department of Anthropology, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Brain Function Research Group, School of Physiology, Faculty of Health Science, University of the Witwatersrand, Johannesburg, South Africa
| | - Louise Barrett
- Brain Function Research Group, School of Physiology, Faculty of Health Science, University of the Witwatersrand, Johannesburg, South Africa.,Department of Psychology, University of Lethbridge, Lethbridge, Canada
| | - Andrea Fuller
- Brain Function Research Group, School of Physiology, Faculty of Health Science, University of the Witwatersrand, Johannesburg, South Africa
| | - Robyn S Hetem
- Brain Function Research Group, School of Physiology, Faculty of Health Science, University of the Witwatersrand, Johannesburg, South Africa.,School of Animal, Plant and Environmental Sciences, Faculty of Science, University of the Witwatersrand, Johannesburg, South Africa
| | - Warren P Porter
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Christopher Young
- Applied Behavioural Ecology & Ecosystems Research Unit, University of South Africa, Pretoria, South Africa.,Endocrine Research Laboratory, Mammal Research Institute, Faculty of Natural and Agricultural Science, University of Pretoria, Pretoria, South Africa
| | - S Peter Henzi
- Department of Psychology, University of Lethbridge, Lethbridge, Canada.,Applied Behavioural Ecology & Ecosystems Research Unit, University of South Africa, Pretoria, South Africa
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10
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Dausmann KH, Levesque DL, Wein J, Nowack J. Ambient Temperature Cycles Affect Daily Torpor and Hibernation Patterns in Malagasy Tenrecs. Front Physiol 2020; 11:522. [PMID: 32547412 PMCID: PMC7270353 DOI: 10.3389/fphys.2020.00522] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 04/28/2020] [Indexed: 11/30/2022] Open
Abstract
Hibernation and daily torpor (heterothermy) allow endotherms to cope with demanding environmental conditions. The depth and duration of torpor bouts vary considerably between tropical and temperate climates, and tropical hibernators manage to cope with a wider spectrum of ambient temperature (Ta) regimes during heterothermy. As cycles in Ta can have profound effects on activity and torpor patterns as well as energy expenditure, we examined how these characteristics are affected by daily fluctuating versus constant Ta in a tropical hibernator, the lesser hedgehog tenrec (Echinops telfairi). Throughout the study, regardless of season, the tenrecs became torpid every day. In summer, E. telfairi used daily fluctuations in Ta to passively rewarm from daily torpor, which led to synchrony in the activity phases and torpor bouts between individuals and generally decreased energy expenditure. In contrast, animals housed at constant Ta showed considerable variation in timing and they had to invest more energy through endogenous heat production. During the hibernation season (winter) E. telfairi hibernated for several months in constant, as well as in fluctuating Ta and, as in summer, under fluctuating Ta arousals were much more uniform and showed less variation in timing compared to constant temperature regimes. The timing of torpor is not only important for its effective use, but synchronization of activity patterns could also be essential for social interactions, and successful foraging bouts. Our results highlight that Ta cycles can be an effective zeitgeber for activity and thermoregulatory rhythms throughout the year and that consideration should be given to the choice of temperature regime when studying heterothermy under laboratory conditions.
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Affiliation(s)
- Kathrin H Dausmann
- Functional Ecology, Institute of Zoology, University of Hamburg, Hamburg, Germany
| | - Danielle L Levesque
- School of Biology and Ecology, University of Maine, Orono, ME, United States
| | - Jens Wein
- Functional Ecology, Institute of Zoology, University of Hamburg, Hamburg, Germany
| | - Julia Nowack
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, United Kingdom
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11
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Nowack J, Levesque DL, Reher S, Dausmann KH. Variable Climates Lead to Varying Phenotypes: “Weird” Mammalian Torpor and Lessons From Non-Holarctic Species. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00060] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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12
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McFarland R, Barrett L, Costello M, Fuller A, Hetem RS, Maloney SK, Mitchell D, Henzi PS. Keeping cool in the heat: Behavioral thermoregulation and body temperature patterns in wild vervet monkeys. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2019; 171:407-418. [DOI: 10.1002/ajpa.23962] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 10/19/2019] [Accepted: 10/22/2019] [Indexed: 01/27/2023]
Affiliation(s)
- Richard McFarland
- Department of AnthropologyUniversity of Wisconsin–Madison Madison Wisconsin
- Brain Function Research Group, School of Physiology, Faculty of Health SciencesUniversity of the Witwatersrand Johannesburg South Africa
| | - Louise Barrett
- Brain Function Research Group, School of Physiology, Faculty of Health SciencesUniversity of the Witwatersrand Johannesburg South Africa
- Department of PsychologyUniversity of Lethbridge Lethbridge Canada
- Applied Behavioural Ecology & Ecosystems Research UnitUniversity of South Africa Pretoria South Africa
| | - Mary‐Ann Costello
- Central Animal ServicesUniversity of the Witwatersrand Johannesburg South Africa
| | - Andrea Fuller
- Brain Function Research Group, School of Physiology, Faculty of Health SciencesUniversity of the Witwatersrand Johannesburg South Africa
| | - Robyn S. Hetem
- Brain Function Research Group, School of Physiology, Faculty of Health SciencesUniversity of the Witwatersrand Johannesburg South Africa
- School of Animal, Plant and Environmental Sciences, Faculty of ScienceUniversity of the Witwatersrand Johannesburg South Africa
| | - Shane K. Maloney
- Brain Function Research Group, School of Physiology, Faculty of Health SciencesUniversity of the Witwatersrand Johannesburg South Africa
- School of Human SciencesUniversity of Western Australia Perth Western Australia Australia
| | - Duncan Mitchell
- Brain Function Research Group, School of Physiology, Faculty of Health SciencesUniversity of the Witwatersrand Johannesburg South Africa
- School of Human SciencesUniversity of Western Australia Perth Western Australia Australia
| | - Peter S. Henzi
- Department of PsychologyUniversity of Lethbridge Lethbridge Canada
- Applied Behavioural Ecology & Ecosystems Research UnitUniversity of South Africa Pretoria South Africa
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13
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Andrews MT. Molecular interactions underpinning the phenotype of hibernation in mammals. J Exp Biol 2019; 222:222/2/jeb160606. [DOI: 10.1242/jeb.160606] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
ABSTRACT
Mammals maintain a constant warm body temperature, facilitating a wide variety of metabolic reactions. Mammals that hibernate have the ability to slow their metabolism, which in turn reduces their body temperature and leads to a state of hypothermic torpor. For this metabolic rate reduction to occur on a whole-body scale, molecular interactions that change the physiology of cells, tissues and organs are required, resulting in a major departure from normal mammalian homeostasis. The aim of this Review is to cover recent advances in the molecular biology of mammalian hibernation, including the role of small molecules, seasonal changes in gene expression, cold-inducible RNA-binding proteins, the somatosensory system and emerging information on hibernating primates. To underscore the importance of differential gene expression across the hibernation cycle, mRNA levels for 14,261 ground squirrel genes during periods of activity and torpor are made available for several tissues via an interactive transcriptome browser. This Review also addresses recent findings on molecular interactions responsible for multi-day survival of near-freezing body temperatures, single-digit heart rates and a slowed metabolism that greatly reduces oxygen consumption. A better understanding of how natural hibernators survive these physiological extremes is beginning to lead to innovations in human medicine.
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Affiliation(s)
- Matthew T. Andrews
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
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14
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Boratyński JS, Iwińska K, Bogdanowicz W. Body temperature variation in free-living and food-deprived yellow-necked mice sustains an adaptive framework for endothermic thermoregulation. MAMMAL RES 2018. [DOI: 10.1007/s13364-018-0392-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Blanco MB, Dausmann KH, Faherty SL, Yoder AD. Tropical heterothermy is “cool”: The expression of daily torpor and hibernation in primates. Evol Anthropol 2018; 27:147-161. [DOI: 10.1002/evan.21588] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 03/15/2018] [Indexed: 12/19/2022]
Affiliation(s)
| | | | | | - Anne D. Yoder
- Duke Lemur Center; Durham North Carolina
- Department of Biology; Duke University; Durham North Carolina
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16
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Sleep patterns, daytime predation, and the evolution of diurnal sleep site selection in lorisiforms. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 166:563-577. [DOI: 10.1002/ajpa.23450] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 02/02/2018] [Accepted: 02/15/2018] [Indexed: 12/30/2022]
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17
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Levesque DL, Tuen AA, Lovegrove BG. Staying hot to fight the heat-high body temperatures accompany a diurnal endothermic lifestyle in the tropics. J Comp Physiol B 2018; 188:707-716. [PMID: 29623412 DOI: 10.1007/s00360-018-1160-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 03/20/2018] [Accepted: 04/01/2018] [Indexed: 11/25/2022]
Affiliation(s)
- Danielle L Levesque
- Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, 94300, Kota Samarahan, Sarawak, Malaysia.
- School of Biology and Ecology, University of Maine, Orono, ME, 04469, USA.
| | - Andrew Alek Tuen
- School of Biology and Ecology, University of Maine, Orono, ME, 04469, USA
| | - Barry G Lovegrove
- School of Life Sciences, University of KwaZulu-Natal, P/Bag X01, Scottsville, 3209, South Africa
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18
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Faherty SL, Villanueva‐Cañas JL, Blanco MB, Albà MM, Yoder AD. Transcriptomics in the wild: Hibernation physiology in free‐ranging dwarf lemurs. Mol Ecol 2018; 27:709-722. [DOI: 10.1111/mec.14483] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 12/13/2017] [Accepted: 12/14/2017] [Indexed: 12/30/2022]
Affiliation(s)
| | - José Luis Villanueva‐Cañas
- Institute of Evolutionary Biology (CSIC‐Universitat Pompeu Fabra) Barcelona Spain
- Evolutionary Genomics Group Research Programme on Biomedical Informatics (GRIB) Hospital del Mar Research Institute (IMIM) Universitat Pompeu Fabra (UPF) Barcelona Spain
| | | | - M. Mar Albà
- Evolutionary Genomics Group Research Programme on Biomedical Informatics (GRIB) Hospital del Mar Research Institute (IMIM) Universitat Pompeu Fabra (UPF) Barcelona Spain
- Catalan Institution for Research and Advanced Studies (ICREA) Barcelona Spain
| | - Anne D. Yoder
- Department of Biology Duke University Durham NC USA
- Duke Lemur Center Durham NC USA
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19
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Welman S, Tuen AA, Lovegrove BG. Searching for the Haplorrhine Heterotherm: Field and Laboratory Data of Free-Ranging Tarsiers. Front Physiol 2017; 8:745. [PMID: 29018365 PMCID: PMC5623056 DOI: 10.3389/fphys.2017.00745] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 09/12/2017] [Indexed: 01/26/2023] Open
Abstract
The observation of heterothermy in a single suborder (Strepsirrhini) only within the primates is puzzling. Given that the placental-mammal ancestor was likely a heterotherm, we explored the potential for heterothermy in a primate closely related to the Strepsirrhini. Based upon phylogeny, body size and habitat stability since the Late Eocene, we selected western tarsiers (Cephalopachus bancanus) from the island of Borneo. Being the sister clade to Strepsirrhini and basal in Haplorrhini (monkeys and apes), we hypothesized that C. bancanus might have retained the heterothermic capacity observed in several small strepsirrhines. We measured resting metabolic rate, subcutaneous temperature, evaporative water loss and the percentage of heat dissipated through evaporation, at ambient temperatures between 22 and 35°C in fresh-caught wild animals (126.1 ± 2.4 g). We also measured core body temperatures in free-ranging animals. The thermoneutral zone was 25-30°C and the basal metabolic rate was 3.52 ± 0.06 W.kg-1 (0.65 ± 0.01 ml O2.g-1.h-1). There was no evidence of adaptive heterothermy in either the laboratory data or the free-ranging data. Instead, animals appeared to be cold sensitive (Tb ~ 31°C) at the lowest temperatures. We discuss possible reasons for the apparent lack of heterothermy in tarsiers, and identify putative heterotherms within Platyrrhini. We also document our concern for the vulnerability of C. bancanus to future temperature increases associated with global warming.
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Affiliation(s)
- Shaun Welman
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Andrew A. Tuen
- Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, Kota Samarahan, Malaysia
| | - Barry G. Lovegrove
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
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20
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The effect of body mass and diet composition on torpor patterns in a Malagasy primate (Microcebus murinus). J Comp Physiol B 2016; 187:677-688. [DOI: 10.1007/s00360-016-1045-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Revised: 10/19/2016] [Accepted: 10/20/2016] [Indexed: 10/20/2022]
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21
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Dausmann KH, Warnecke L. Primate Torpor Expression: Ghost of the Climatic Past. Physiology (Bethesda) 2016; 31:398-408. [DOI: 10.1152/physiol.00050.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Torpor, the controlled depression of virtually all bodily function during scarce periods, was verified in primates under free-ranging conditions less than two decades ago. The large variety of different torpor patterns found both within and among closely related species is particularly remarkable. To help unravel the cause of these variable patterns, our review investigates primate torpor use within an evolutionary framework. First, we provide an overview of heterothermic primate species, focusing on the Malagasy lemurs, and discuss their use of daily torpor or hibernation in relation to habitat type and climatic conditions. Second, we investigate environmental characteristics that may have been involved in shaping the high variability of torpor expression found in lemurs today. Third, we examine potential triggers for torpor use in lemurs. We propose the “torpor refugia hypothesis” to illustrate how disparate primate torpor patterns possibly evolved in response to environmental cues during glacial periods, when animals were restricted to different refuge habitats along riverine corridors. For example, individuals enduring harsher conditions at higher altitudes likely developed seasonal hibernation, whereas those inhabiting lower elevation river catchments might have coped with unfavorable conditions by employing daily torpor. The ultimate stimuli triggering torpor use today likely differ between the different habitats of Madagascar. The broad diversity of torpor patterns in lemurs among closely related species, both within the same and in distinctly different habitat types, provides an ideal base for research into the stimuli for torpor use in endotherms in general. Our hypothesis highlights the importance of considering the environmental conditions under which ecosystems and species evolved when trying to explain physiological adaptations seen today.
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Affiliation(s)
- Kathrin H. Dausmann
- Zoological Institute, Functional Ecology, University Hamburg, Hamburg, Germany
| | - Lisa Warnecke
- Zoological Institute, Functional Ecology, University Hamburg, Hamburg, Germany
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22
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Naya DE, Naya H, Lessa EP. Brain size and thermoregulation during the evolution of the genus Homo. Comp Biochem Physiol A Mol Integr Physiol 2016; 191:66-73. [DOI: 10.1016/j.cbpa.2015.09.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 08/18/2015] [Accepted: 09/24/2015] [Indexed: 11/16/2022]
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23
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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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24
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The hustle and bustle of city life: monitoring the effects of urbanisation in the African lesser bushbaby. Naturwissenschaften 2015; 102:57. [DOI: 10.1007/s00114-015-1305-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 08/11/2015] [Accepted: 08/19/2015] [Indexed: 11/26/2022]
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25
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Ruf T, Geiser F. Daily torpor and hibernation in birds and mammals. Biol Rev Camb Philos Soc 2015; 90:891-926. [PMID: 25123049 PMCID: PMC4351926 DOI: 10.1111/brv.12137] [Citation(s) in RCA: 484] [Impact Index Per Article: 53.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 07/16/2014] [Accepted: 07/16/2014] [Indexed: 12/11/2022]
Abstract
Many birds and mammals drastically reduce their energy expenditure during times of cold exposure, food shortage, or drought, by temporarily abandoning euthermia, i.e. the maintenance of high body temperatures. Traditionally, two different types of heterothermy, i.e. hypometabolic states associated with low body temperature (torpor), have been distinguished: daily torpor, which lasts less than 24 h and is accompanied by continued foraging, versus hibernation, with torpor bouts lasting consecutive days to several weeks in animals that usually do not forage but rely on energy stores, either food caches or body energy reserves. This classification of torpor types has been challenged, suggesting that these phenotypes may merely represent extremes in a continuum of traits. Here, we investigate whether variables of torpor in 214 species (43 birds and 171 mammals) form a continuum or a bimodal distribution. We use Gaussian-mixture cluster analysis as well as phylogenetically informed regressions to quantitatively assess the distinction between hibernation and daily torpor and to evaluate the impact of body mass and geographical distribution of species on torpor traits. Cluster analysis clearly confirmed the classical distinction between daily torpor and hibernation. Overall, heterothermic endotherms tend to be small; hibernators are significantly heavier than daily heterotherms and also are distributed at higher average latitudes (∼35°) than daily heterotherms (∼25°). Variables of torpor for an average 30 g heterotherm differed significantly between daily heterotherms and hibernators. Average maximum torpor bout duration was >30-fold longer, and mean torpor bout duration >25-fold longer in hibernators. Mean minimum body temperature differed by ∼13°C, and the mean minimum torpor metabolic rate was ∼35% of the basal metabolic rate (BMR) in daily heterotherms but only 6% of BMR in hibernators. Consequently, our analysis strongly supports the view that hibernators and daily heterotherms are functionally distinct groups that probably have been subject to disruptive selection. Arguably, the primary physiological difference between daily torpor and hibernation, which leads to a variety of derived further distinct characteristics, is the temporal control of entry into and arousal from torpor, which is governed by the circadian clock in daily heterotherms, but apparently not in hibernators.
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Affiliation(s)
- Thomas Ruf
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Savoyenstraße 1, A-1160 Vienna, Austria
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, New South Wales 2351, Australia
| | - Fritz Geiser
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, New South Wales 2351, Australia
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26
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Affiliation(s)
- Julia Nowack
- Department of Animal Ecology and Conservation; Biocentre Grindel; University of Hamburg; Martin-Luther-King Platz 3 20146 Hamburg Germany
- Centre for Behavioural and Physiological Ecology, Zoology; University of New England; Armidale NSW 2351 Australia
| | - Kathrin H. Dausmann
- Department of Animal Ecology and Conservation; Biocentre Grindel; University of Hamburg; Martin-Luther-King Platz 3 20146 Hamburg Germany
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27
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McAllan BM, Geiser F. Torpor during reproduction in mammals and birds: dealing with an energetic conundrum. Integr Comp Biol 2014; 54:516-32. [PMID: 24973362 DOI: 10.1093/icb/icu093] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Torpor and reproduction in mammals and birds are widely viewed as mutually exclusive processes because of opposing energetic and hormonal demands. However, the reported number of heterothermic species that express torpor during reproduction is ever increasing, to some extent because of recent work on free-ranging animals. We summarize current knowledge about those heterothermic mammals that do not express torpor during reproduction and, in contrast, examine those heterothermic birds and mammals that do use torpor during reproduction. Incompatibility between torpor and reproduction occurs mainly in high-latitude sciurid and cricetid rodents, which live in strongly seasonal, but predictably productive habitats in summer. In contrast, torpor during incubation, brooding, pregnancy, or lactation occurs in nightjars, hummingbirds, echidnas, several marsupials, tenrecs, hedgehogs, bats, carnivores, mouse lemurs, and dormice. Animals that enter torpor during reproduction often are found in unpredictable habitats, in which seasonal availability of food can be cut short by changes in weather, or are species that reproduce fully or partially during winter. Moreover, animals that use torpor during the reproductive period have relatively low reproductive costs, are largely insectivorous, carnivorous, or nectarivorous, and thus rely on food that can be unpredictable or strongly seasonal. These species with relatively unpredictable food supplies must gain an advantage by using torpor during reproduction because the main cost is an extension of the reproductive period; the benefit is increased survival of parent and offspring, and thus fitness.
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Affiliation(s)
- B M McAllan
- *Department of Physiology, School of Medical Sciences and Bosch Institute, The University of Sydney, Sydney, New South Wales 2006, Australia; Centre for Behavioural and Physiological Ecology, Department of Zoology, University of New England, Armidale, New South Wales 2351, Australia*Department of Physiology, School of Medical Sciences and Bosch Institute, The University of Sydney, Sydney, New South Wales 2006, Australia; Centre for Behavioural and Physiological Ecology, Department of Zoology, University of New England, Armidale, New South Wales 2351, Australia
| | - Fritz Geiser
- *Department of Physiology, School of Medical Sciences and Bosch Institute, The University of Sydney, Sydney, New South Wales 2006, Australia; Centre for Behavioural and Physiological Ecology, Department of Zoology, University of New England, Armidale, New South Wales 2351, Australia
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28
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Torpor is not the only option: seasonal variations of the thermoneutral zone in a small primate. J Comp Physiol B 2014; 184:789-97. [PMID: 24942312 DOI: 10.1007/s00360-014-0834-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 04/30/2014] [Accepted: 05/08/2014] [Indexed: 10/25/2022]
Abstract
The reddish-gray mouse lemur (Microcebus griseorufus) is one of only a few small mammals inhabiting the spiny forest of southwestern Madagascar. In this study we investigated the physiological adjustments which allow these small primates to persist under the challenging climatic conditions of their habitat. To this end we measured energy expenditure (metabolic rate) and body temperature of 24 naturally acclimatized mouse lemurs, kept in outdoor enclosures, during different seasons (summer, winter, and the transition period between the two seasons). Mouse lemurs displayed two main physiological strategies to compensate seasonal and diurnal fluctuations of ambient temperature. On the one hand, individuals entered hypometabolism with decreasing ambient temperature (T a) during the transition period and winter, enabling them to save up to 21 % energy per day (92 % per hour) compared with the normal resting metabolic rate at comparable T a. On the other hand, euthermic mouse lemurs also showed physiological adjustments to seasonality when resting: the lower critical temperature of the thermoneutral zone decreased from summer to winter by 7.5 °C, which allowed mouse lemurs to keep energy demands constant despite colder T as during winter. In addition, the basal metabolic rate was substantially lowered prior to the winter period, which facilitated accumulation of fat reserves. The combination of physiological modifications during euthermia in addition to hypometabolism, which can be individually adjusted according to external parameters and respective body condition, is important as it allows M. griseorufus to cope with the environmental variability of an energetically challenging habitat.
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29
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Lubbe A, Hetem RS, McFarland R, Barrett L, Henzi PS, Mitchell D, Meyer LCR, Maloney SK, Fuller A. Thermoregulatory plasticity in free-ranging vervet monkeys, Chlorocebus pygerythrus. J Comp Physiol B 2014; 184:799-809. [PMID: 24938639 DOI: 10.1007/s00360-014-0835-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 05/12/2014] [Accepted: 05/28/2014] [Indexed: 11/27/2022]
Abstract
We used implanted miniature data loggers to obtain the first measurements of body temperature from a free-ranging anthropoid primate. Vervet monkeys (Chlorocebus pygerythrus) living in a highly seasonal, semi-arid environment maintained a lower mean 24-h body temperature in winter (34.6 ± 0.5 °C) than in summer (36.2 ± 0.1 °C), and demonstrated increased heterothermy (as indexed by the 24-h amplitude of their body temperature rhythm) in response to proximal environmental stressors. The mean 24-h amplitude of the body temperature rhythm in summer (2.5 ± 0.1 °C) was lower than that in winter (3.2 ± 0.4 °C), with the highest amplitude for an individual monkey (5.6 °C) recorded in winter. The higher amplitude of the body temperature rhythm in winter was a consequence primarily of lower 24-h minimum body temperatures during the nocturnal phase, when monkeys were inactive. These low minimum body temperatures were associated with low black globe temperature (GLMM, β = 0.046, P < 0.001), short photoperiod (β = 0.010, P < 0.001) and low rainfall over the previous 2 months, which we used as a proxy for food availability (β = 0.001, P < 0.001). Despite the lower average winter minimum body temperatures, there was no change in the lower modal body temperature between winter and summer. Therefore, unlike the regulated physiological adjustments proposed for torpor or hibernation, these minimum winter body temperatures did not appear to reflect a regulated reduction in body temperature. The thermoregulatory plasticity nevertheless may have fitness benefits for vervet monkeys.
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Affiliation(s)
- Alwyn Lubbe
- Brain Function Research Group, Faculty of Health Sciences, School of Physiology, University of the Witwatersrand, 7 York Road, Medical School, Parktown, Johannesburg, 2193, South Africa,
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30
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Nowack J, Dausmann KH, Mzilikazi N. Nonshivering thermogenesis in the African lesser bushbaby, Galago moholi. ACTA ACUST UNITED AC 2014; 216:3811-7. [PMID: 24068349 DOI: 10.1242/jeb.089433] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The capacity for nonshivering thermogenesis (NST) plays an important role during arousal from torpid states. Recent data on heterotherms inhabiting warmer regions, however, suggest that passive rewarming reduces the need of metabolic heat production during arousal significantly, leading to the question: to what extent do subtropical or tropical heterotherms depend on NST? The African lesser bushbaby, Galago moholi, enters torpid states as an emergency response only, but otherwise stays normothermic throughout the cold and dry winter season. In addition, this species shows unusual rewarming difficulties during arousal from torpor on cold days. We therefore examined the seasonal adjustments of the capacity for NST of naturally acclimatized G. moholi by stimulation with noradrenaline (NA) injection. Dissection of two adult female bushbabies revealed that G. moholi possesses brown adipose tissue, and NA treatment (0.5 mg kg(-1), s.c.) induced a significant elevation in oxygen consumption compared with control (saline) injection. However, the increase in oxygen consumption following injection of NA was not significantly different between winter and summer. Our results show that the ability to produce heat via NST seems to be available throughout the year and that G. moholi is able to change NST capacity within a very short time frame in response to cold spells. Together with results from studies on other (Afro-)tropical heterotherms, which also indicate low or even absent seasonal difference in NST capacity, this raises the question of whether the definition of NST needs to be refined for (Afro-)tropical mammals.
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Affiliation(s)
- Julia Nowack
- Department of Animal Ecology and Conservation, Biocentre Grindel, University of Hamburg, Martin-Luther-King Platz 3, 20146 Hamburg, Germany
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31
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Pretzlaff I, Rau D, H. Dausmann K. Energy expenditure increases during the active season in the small, free-living hibernator Muscardinus avellanarius. Mamm Biol 2014. [DOI: 10.1016/j.mambio.2013.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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32
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Thompson CL, Williams SH, Glander KE, Teaford MF, Vinyard CJ. Body temperature and thermal environment in a generalized arboreal anthropoid, wild mantled howling monkeys (Alouatta palliata). AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2014; 154:1-10. [PMID: 24610247 DOI: 10.1002/ajpa.22505] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 02/23/2014] [Indexed: 11/08/2022]
Abstract
Free-ranging primates are confronted with the challenge of maintaining an optimal range of body temperatures within a thermally dynamic environment that changes daily, seasonally, and annually. While many laboratory studies have been conducted on primate thermoregulation, we know comparatively little about the thermal pressures primates face in their natural, evolutionarily relevant environment. Such knowledge is critical to understanding the evolution of thermal adaptations in primates and for comparative evaluation of humans' unique thermal adaptations. We examined temperature and thermal environment in free-ranging, mantled howling monkeys (Alouatta palliata) in a tropical dry forest in Guanacaste, Costa Rica. We recorded subcutaneous (Tsc ) and near-animal ambient temperatures (Ta ) from 11 animals over 1586.5 sample hours during wet and dry seasons. Howlers displayed considerable variation in Tsc , which was largely attributable to circadian effects. Despite significant seasonal changes in the ambient thermal environment, howlers showed relatively little evidence for seasonal changes in Tsc . Howlers experienced warm thermal conditions which led to body cooling relative to the environment, and plateaus in Tsc at increasingly warm Ta . They also frequently faced cool thermal conditions (Ta < Tsc ) in which Tsc was markedly elevated compared with Ta . These data add to a growing body of evidence that non-human primates have more labile body temperatures than humans. Our data additionally support a hypothesis that, despite inhabiting a dry tropical environment, howling monkeys experience both warm and cool thermal pressures. This suggests that thermal challenges may be more prevalent for primates than previously thought, even for species living in nonextreme thermal environments.
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Affiliation(s)
- Cynthia L Thompson
- Department of Biomedical Sciences, Grand Valley State University, Allendale, MI
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33
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Affiliation(s)
- K. H. Dausmann
- Department of Animal Ecology and Conservation, Biocentre Grindel; University of Hamburg; Hamburg Germany
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34
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Kronfeld-Schor N, Dayan T. Thermal Ecology, Environments, Communities, and Global Change: Energy Intake and Expenditure in Endotherms. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2013. [DOI: 10.1146/annurev-ecolsys-110512-135917] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To survive, animals must maintain a balance between energy acquisition (foraging) and energy expenditure. This challenge is particularly great for endotherm vertebrates that require high amounts of energy to maintain homeothermy. Many of these endotherms use hibernation or daily torpor as a mechanism to reduce energy expenditure during anticipated or stochastic periods of stress. Although ecological researchers have focused extensively on energy acquisition, physiologists have largely studied thermal ecology and the mechanisms allowing endotherms to regulate energy expenditure, with little research explicitly linking ecology and thermal biology. Nevertheless, theoretical considerations and research conducted so far point to a significant ecological role for torpor in endotherms. Moreover, global-change challenges facing vertebrate endotherms are also considered in view of their ability to regulate their energy expenditure. We review the thermal ecology of endothermic vertebrates and some of its ecological and evolutionary implications.
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Affiliation(s)
| | - Tamar Dayan
- Department of Zoology, Tel Aviv University, Tel Aviv 69978, Israel;,
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35
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Dausmann KH, Wein J, Turner JM, Glos J. Absence of heterothermy in the European red squirrel (Sciurus vulgaris). Mamm Biol 2013. [DOI: 10.1016/j.mambio.2013.01.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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36
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Obligate exudativory characterizes the diet of the pygmy slow lorisNycticebus pygmaeus. Am J Primatol 2013; 75:1054-61. [DOI: 10.1002/ajp.22171] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2012] [Revised: 04/29/2013] [Accepted: 05/04/2013] [Indexed: 11/07/2022]
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37
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Nowack J, Mzilikazi N, Dausmann KH. Torpor as an emergency solution in Galago moholi: heterothermy is triggered by different constraints. J Comp Physiol B 2012; 183:547-56. [DOI: 10.1007/s00360-012-0725-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 10/17/2012] [Accepted: 11/22/2012] [Indexed: 10/27/2022]
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38
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Surviving the Cold, Dry Period in Africa: Behavioral Adjustments as an Alternative to Heterothermy in the African Lesser Bushbaby (Galago moholi). INT J PRIMATOL 2012. [DOI: 10.1007/s10764-012-9646-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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39
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Starr C, Nekaris KAI, Leung L. Hiding from the moonlight: luminosity and temperature affect activity of Asian nocturnal primates in a highly seasonal forest. PLoS One 2012; 7:e36396. [PMID: 22558461 PMCID: PMC3338665 DOI: 10.1371/journal.pone.0036396] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 04/04/2012] [Indexed: 11/29/2022] Open
Abstract
The effect of moonlight and temperature on activity of slow lorises was previously little known and this knowledge might be useful for understanding many aspects of their behavioural ecology, and developing strategies to monitor and protect populations. In this study we aimed to determine if the activity of the pygmy loris (Nycticebus pygmaeus) is affected by ambient temperature and/or moonlight in a mixed deciduous forest. We radio-collared five females and five males in the Seima Protection Forest, Cambodia, in February to May, 2008 and January to March, 2009 and recorded their behaviour at 5 minutes intervals, totalling 2736 observations. We classified each observation as either inactive (sleeping or alert) or active behaviour (travel, feeding, grooming, or others). Moon luminosity (bright/dark) and ambient temperature were recorded for each observation. The response variable, activity, was binary (active or inactive), and a logit link function was used. Ambient temperature alone did not significantly affect mean activity. Although mean activity was significantly affected by moonlight, the interaction between moonlight and temperature was also significant: on bright nights, studied animals were increasingly more active with higher temperature; and on dark nights they were consistently active regardless of temperature. The most plausible explanation is that on bright cold nights the combined risk of being seen and attacked by predators and heat loss outweigh the benefit of active behaviours.
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Affiliation(s)
- Carly Starr
- School of Agriculture and Food Science, University of Queensland, Gatton, Queensland, Australia.
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McKechnie AE, Mzilikazi N. Heterothermy in Afrotropical mammals and birds: a review. Integr Comp Biol 2011; 51:349-63. [PMID: 21705792 DOI: 10.1093/icb/icr035] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Recent years have seen a rapid increase in the number of Afrotropical endotherms known to avoid mismatches between energy supply and demand by using daily torpor and/or hibernation. Among mammals, heterothermy has been reported in 40 species in six orders, namely Macroscelidea, Afrosoricida, Rodentia, Eulipotyphla, Primates and Chiroptera. These species span a range in body mass of 7-770 g, with minimum heterothermic body temperatures ranging from 1-27°C and bout length varying from 1 h to 70 days. Daily torpor is the most common form of heterothermy, with true hibernation being observed in only seven species, Graphiurus murinus, Graphiurus ocularis, Atelerix frontalis, Cheirogaleus medius, Cheirogaleus major, Microcebus murinus and Microcebus griseorufus. The traditional distinction between daily torpor and hibernation is blurred in some species, with free-ranging individuals exhibiting bouts of > 24 h and body temperatures < 16 °C, but none of the classical behaviours associated with hibernation. Several species bask in the sun during rewarming. Among birds, heterothermy has been reported in 16 species in seven orders, and is more pronounced in phylogenetically older taxa. Both in mammals and birds, patterns of heterothermy can vary dramatically among species occurring at a particular site, and even among individuals of a single species. For instance, patterns of heterothermy among cheirogalid primates in western Madagascar vary from daily torpor to uninterrupted hibernation for up to seven months. Other examples of variation among closely-related species involve small owls, elephant shrews and vespertilionid bats. There may also be variation in terms of the ecological correlates of torpor within a species, as is the case in the Freckled Nightjar Caprimulgus tristigma.
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Affiliation(s)
- Andrew E McKechnie
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa.
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Lovegrove BG. The evolution of endothermy in Cenozoic mammals: a plesiomorphic-apomorphic continuum. Biol Rev Camb Philos Soc 2011; 87:128-62. [DOI: 10.1111/j.1469-185x.2011.00188.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Bohr YEMB, Giertz P, Ratovonamana YR, Ganzhorn JU. Gray-brown Mouse Lemurs (Microcebus griseorufus) as an Example of Distributional Constraints through Increasing Desertification. INT J PRIMATOL 2011. [DOI: 10.1007/s10764-011-9509-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Heterothermy in the southern African hedgehog, Atelerix frontalis. J Comp Physiol B 2010; 181:437-45. [PMID: 21082184 DOI: 10.1007/s00360-010-0531-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 10/20/2010] [Accepted: 10/29/2010] [Indexed: 10/18/2022]
Abstract
Most research on mammalian heterothermic responses in southern Africa tends to be laboratory based and biased towards rodents and smaller members of the Afrotheria. In this study, we continuously measured body temperature of southern African hedgehogs (Atelerix frontalis) between April and August 2009 (-10°C < T (a) < 43°C), kept under semi-captive conditions. A. frontalis showed a high propensity for torpor with animals spending up to 84% of the measurement period torpid. During this study, A. frontalis displayed the lowest T (b min) (ca 1°C) yet recorded in an Afrotropical placental heterotherm. Bout lengths of between 0.7 h (40 min) and 116.3 h (4.8 days) were recorded. Differences in bout length were observed between lighter individuals compared with an individual exhibiting a higher body mass at the onset of winter, with low M (b) individuals exhibiting daily torpor whereas a heavier individual exhibited torpor bouts that were indicative of hibernation. Our results suggest that heterothermic responses are an important feature in the energy balance equation of this species and that body mass at the onset of winter may determine the patterns of heterothermy utilised in this species.
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