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Goh G, Vesterdorf K, Fuller A, Blache D, Maloney SK. Optimal sampling interval for characterisation of the circadian rhythm of body temperature in homeothermic animals using periodogram and cosinor analysis. Ecol Evol 2024; 14:e11243. [PMID: 38601852 PMCID: PMC11004550 DOI: 10.1002/ece3.11243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 03/19/2024] [Accepted: 03/25/2024] [Indexed: 04/12/2024] Open
Abstract
Core body temperature (T c) is a critical aspect of homeostasis in birds and mammals and is increasingly used as a biomarker of the fitness of an animal to its environment. Periodogram and cosinor analysis can be used to estimate the characteristics of the circadian rhythm of T c from data obtained on loggers that have limited memory capacity and battery life. The sampling interval can be manipulated to maximise the recording period, but the impact of sampling interval on the output of periodogram or cosinor analysis is unknown. Some basic guidelines are available from signal analysis theory, but those guidelines have never been tested on T c data. We obtained data at 1-, 5- or 10-min intervals from nine avian or mammalian species, and re-sampled those data to simulate logging at up to 240-min intervals. The period of the rhythm was first analysed using the Lomb-Scargle periodogram, and the mesor, amplitude, acrophase and adjusted coefficient of determination (R 2) from the original and the re-sampled data were obtained using cosinor analysis. Sampling intervals longer than 60 min did not affect the average mesor, amplitude, acrophase or adjusted R 2, but did impact the estimation of the period of the rhythm. In most species, the period was not detectable when intervals longer than 120 min were used. In all individual profiles, a 30-min sampling interval modified the values of the mesor and amplitude by less than 0.1°C, and the adjusted R 2 by less than 0.1. At a 30-min interval, the acrophase was accurate to within 15 min for all species except mice. The adjusted R 2 increased as sampling frequency decreased. In most cases, a 30-min sampling interval provides a reliable estimate of the circadian T c rhythm using periodogram and cosinor analysis. Our findings will help biologists to select sampling intervals to fit their research goals.
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Affiliation(s)
- Grace Goh
- School of Human SciencesThe University of Western AustraliaCrawleyWestern AustraliaAustralia
| | - Kristine Vesterdorf
- School of Human SciencesThe University of Western AustraliaCrawleyWestern AustraliaAustralia
| | - Andrea Fuller
- Brain Function Research Group, School of Physiology, Faculty of Health SciencesUniversity of the WitwatersrandJohannesburgSouth Africa
| | - Dominique Blache
- School of Agriculture and EnvironmentThe University of Western AustraliaCrawleyWestern AustraliaAustralia
| | - Shane K. Maloney
- School of Human SciencesThe University of Western AustraliaCrawleyWestern AustraliaAustralia
- Brain Function Research Group, School of Physiology, Faculty of Health SciencesUniversity of the WitwatersrandJohannesburgSouth Africa
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2
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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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Ellison G, Wolfenden A, Kahana L, Kisingo A, Jamieson J, Jones M, Bettridge CM. Sleeping Site Selection in the Nocturnal Northern Lesser Galago (Galago senegalensis) Supports Antipredator and Thermoregulatory Hypotheses. INT J PRIMATOL 2019. [DOI: 10.1007/s10764-019-00085-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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4
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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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5
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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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6
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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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CABANA F, DIERENFELD ES, Wirdateti, DONATI G, NEKARIS KAI. Exploiting a readily available but hard to digest resource: A review of exudativorous mammals identified thus far and how they cope in captivity. Integr Zool 2018; 13:94-111. [DOI: 10.1111/1749-4877.12264] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Francis CABANA
- Wildlife Nutrition CentreWildlife Reserves Singapore
- Nocturnal Primate Research GroupOxford Brookes University Oxford UK
| | | | - Wirdateti
- Zoological DivisionIndonesian Institute of Science Cibinong Indonesia
| | - Giuseppe DONATI
- Nocturnal Primate Research GroupOxford Brookes University Oxford UK
| | - K. A. I. NEKARIS
- Nocturnal Primate Research GroupOxford Brookes University Oxford UK
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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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9
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Thompson CL, Scheidel C, Glander KE, Williams SH, Vinyard CJ. An assessment of skin temperature gradients in a tropical primate using infrared thermography and subcutaneous implants. J Therm Biol 2017; 63:49-57. [DOI: 10.1016/j.jtherbio.2016.11.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 10/26/2016] [Accepted: 11/02/2016] [Indexed: 10/20/2022]
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10
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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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11
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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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12
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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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13
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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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14
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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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15
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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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16
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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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17
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Boyles JG, Smit B, McKechnie AE. A new comparative metric for estimating heterothermy in endotherms. Physiol Biochem Zool 2011; 84:115-23. [PMID: 20979498 DOI: 10.1086/656724] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A major focus in the study of endothermic thermoregulation has been the description of thermoregulatory patterns used by various species and/or populations. Compared with ectotherms, relatively few attempts have been made to study the thermoregulation of endotherms in an adaptive framework. We believe that one of the main factors limiting this area of research has been the lack of an appropriate metric to directly compare body temperature (T(b)) variation across all endothermic species. Thus, we present a simple comparative metric, the heterothermy index (HI), to quantify the expression of heterothermy by endotherms during a given time frame. Key advantages of HI are that (1) it represents a new analytical technique that has different strengths than the metrics commonly used to describe variation in T(b), (2) it allows for evaluation of nonenergetic costs and benefits that affect the expression of heterothermy, and (3) it has the potential to unify research on homeotherms and heterotherms through quantitative comparative analyses that examine the entire continuum of thermoregulatory patterns. In short, we suggest that our metric provides a means to overcome one of the hurdles presently slowing the advancement of research on endothermic thermoregulation beyond the simple description of thermoregulatory patterns.
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Affiliation(s)
- Justin G Boyles
- DST/NRF Centre of Excellence,Percy FitzPatrick Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa.
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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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Nowack J, Mzilikazi N, Dausmann KH. Torpor on demand: heterothermy in the non-lemur primate Galago moholi. PLoS One 2010; 5:e10797. [PMID: 20520735 PMCID: PMC2875402 DOI: 10.1371/journal.pone.0010797] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Accepted: 05/03/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Hibernation and daily torpor are energy- and water-saving adaptations employed to survive unfavourable periods mostly in temperate and arctic environments, but also in tropical and arid climates. Heterothermy has been found in a number of mammalian orders, but within the primates so far it seems to be restricted to one family of Malagasy lemurs. As currently there is no evidence of heterothermy of a primate outside of Madagascar, the aim of our study was to investigate whether small primates from mainland Africa are indeed always homeothermic despite pronounced seasonal changes in weather and food availability. METHODOLOGY/PRINCIPAL FINDINGS One of the nearest relatives of Malagasy lemurs, the African lesser bushbaby, Galago moholi, which inhabits a highly seasonal habitat with a hot wet-season and a cold dry-season with lower food abundance, was investigated to determine whether it is capable of heterothermy. We measured skin temperature of free-ranging individuals throughout the cool dry season using temperature-sensitive collars as well as metabolic rate in captured individuals. Torpor was employed by 15% of 20 animals. Only one of these animals displayed heterothermy in response to natural availability of food and water, whereas the other animals became torpid without access to food and water. CONCLUSIONS/SIGNIFICANCE Our results show that G. moholi are physiologically capable of employing torpor. However they do not use it as a routine behaviour, but only under adverse conditions. This reluctance is presumably a result of conflicting selective pressures for energy savings versus other ecological and evolutionary forces, such as reproduction or territory defence. Our results support the view that heterothermy in primates evolved before the division of African and Malagasy Strepsirhini, with the possible implication that more primate species than previously thought might still have the potential to call upon this possibility, if the situation necessitates it.
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Affiliation(s)
- Julia Nowack
- Department of Animal Ecology and Conservation, Biocentre Grindel, University of Hamburg, Hamburg, Germany.
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Wilson WA, O'Riain MJ, Hetem RS, Fuller A, Fick LG. Winter body temperature patterns in free-ranging Cape ground squirrel, Xerus inauris: no evidence for torpor. J Comp Physiol B 2010; 180:1099-110. [PMID: 20396893 DOI: 10.1007/s00360-010-0472-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 03/29/2010] [Accepted: 04/01/2010] [Indexed: 11/27/2022]
Abstract
The body temperature (T(b)) of Cape ground squirrels (Xerus inauris, Sciuridae) living in their natural environment during winter has not yet been investigated. In this study we measured abdominal T(b) of eight free-ranging Cape ground squirrels over 27 consecutive days during the austral winter. Mean daily T(b) was relatively stable at 37.0 ± 0.2°C (range 33.4 to 40.2°C) despite a marked variation in globe temperature (T(g)) (range -7 to 37°C). Lactating females (n = 2) consistently had a significantly higher mean T (b) (0.7°C) than non-lactating females (n = 3) and males. There was a pronounced nychthemeral rhythm with a mean active phase T(b) of 38.1 ± 0.1°C and a mean inactive phase T(b) of 36.3 ± 0.3°C for non-lactating individuals. Mean daily amplitude of T(b) rhythm was 3.8 ± 0.2°C. T(b) during the active phase closely followed T(g) and mean active phase T(b) was significantly correlated with mean active phase T(g) (r(2) = 0.3-0.9; P < 0.01). There was no evidence for daily torpor or pronounced hypothermia during the inactive phase, and mean minimum inactive phase T(b) was 35.7 ± 0.3°C for non-lactating individuals. Several alternatives (including nocturnal huddling, an aseasonal breeding pattern and abundant winter food resources) as to why Cape ground squirrels do not employ nocturnal hypothermia are discussed.
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Affiliation(s)
- Wendy A Wilson
- Department of Zoology, University of Cape Town, Rondebosch, Cape Town 7701, South Africa.
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Lovegrove BG. Modification and miniaturization of Thermochron iButtons for surgical implantation into small animals. J Comp Physiol B 2008; 179:451-8. [PMID: 19115060 DOI: 10.1007/s00360-008-0329-x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Revised: 12/04/2008] [Accepted: 12/08/2008] [Indexed: 12/01/2022]
Abstract
Thermochron iButtons are being used increasingly by animal physiologists to measure long-term patterns of body temperature in reptiles, birds and mammals. Typically, iButtons are surgically implanted into the intraperitoneal cavity where they measure and store body temperature together with the date and time from an onboard real-time clock. In 16-bit resolution, the DS1922L iButton can store a total of 4,096 data points over pre-determined sampling intervals. iButtons have proved invaluable in measuring patterns of torpor and hibernation in animals larger than 70 g. Weighing around 3.5 g after potting with wax, iButtons are too heavy and large to implant into animals smaller than 70 g because their weight exceeds 5% of the animal's total body weight. This paper describes how the stainless steel canister housing the DS 1922L iButton battery and circuit board can be removed to reduce the weight of the components to 1.49 g after waxing (ready for implantation) without compromising the function or battery life of the iButton. The modified iButton can be implanted into animals as small as 20-30 g. Calibration data revealed an offset of ca. 1 degrees C on average, confirming that iButtons must be calibrated prior to implantation.
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Affiliation(s)
- Barry G Lovegrove
- School of Biological and Conservation Sciences, University of KwaZulu-Natal, P/Bag X01, Scottsville, South Africa.
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Lovegrove BG, Génin F. Torpor and hibernation in a basal placental mammal, the Lesser Hedgehog Tenrec Echinops telfairi. J Comp Physiol B 2008; 178:691-8. [DOI: 10.1007/s00360-008-0257-9] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2008] [Revised: 03/10/2008] [Accepted: 03/12/2008] [Indexed: 11/28/2022]
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