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Mella VSA, Cooper CE, Karr M, Krockenberger A, Madani G, Webb EB, Krockenberger MB. Hot climate, hot koalas: the role of weather, behaviour and disease on thermoregulation. CONSERVATION PHYSIOLOGY 2024; 12:coae032. [PMID: 38803425 PMCID: PMC11129715 DOI: 10.1093/conphys/coae032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 04/08/2024] [Accepted: 04/30/2024] [Indexed: 05/29/2024]
Abstract
Thermoregulation is critical for endotherms living in hot, dry conditions, and maintaining optimal core body temperature (Tb) in a changing climate is an increasingly challenging task for mammals. Koalas (Phascolarctos cinereus) have evolved physiological and behavioural strategies to maintain homeostasis and regulate their Tb but are thought to be vulnerable to prolonged heat. We investigated how weather, behaviour and disease influence Tb for wild, free-living koalas during summer in north-west New South Wales. We matched Tb with daily behavioural observations in an ageing population where chlamydial disease is prevalent. Each individual koala had similar Tb rhythms (average Tb = 36.4 ± 0.05°C), but male koalas had higher Tb amplitude and more pronounced daily rhythm than females. Disease disrupted the 24-hr circadian pattern of Tb. Koala Tb increased with ambient temperature (Ta). On the hottest day of the study (maximum Ta = 40.8°C), we recorded the highest (Tb = 40.8°C) but also the lowest (Tb = 32.4°C) Tb ever documented for wild koalas, suggesting that they are more heterothermic than previously recognized. This requires individuals to predict days of extreme Ta from overnight and early morning conditions, adjusting Tb regulation accordingly, and it has never been reported before for koalas. The large diel amplitude and low minimum Tb observed suggest that koalas at our study site are energetically and nutritionally compromised, likely due to their age. Behaviour (i.e. tree hugging and drinking water) was not effective in moderating Tb. These results indicate that Ta and koala Tb are strongly interconnected and reinforce the importance of climate projections for predicting the future persistence of koalas throughout their current distribution. Global climate models forecast that dry, hot weather will continue to escalate and drought events will increase in frequency, duration and severity. This is likely to push koalas and other arboreal folivores towards their thermal limit.
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Affiliation(s)
- Valentina S A Mella
- Sydney School of Veterinary Science, The University of Sydney, Sydney, New South Wales 2006, Australia
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Christine E Cooper
- School of Molecular and Life Sciences, Curtin University, Perth, Western Australia 6102, Australia
| | - Madeline Karr
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Andrew Krockenberger
- Division of Research and Innovation, James Cook University, Cairns, Queensland 4878, Australia
| | - George Madani
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
| | - Elliot B Webb
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia
- Department of Planning and Environment, Science, Economics and Insights Division, Parramatta, New South Wales 2150, Australia
| | - Mark B Krockenberger
- Sydney School of Veterinary Science, The University of Sydney, Sydney, New South Wales 2006, Australia
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Adam D, Johnston SD, Beard L, Nicolson V, Lisle AT, Gaughan JB, Larkin R, Theilemann P, Ellis W. Temporal effect of feeding on the body temperature and behaviour of captive koalas (Phascolarctos cinereus). AUSTRALIAN MAMMALOGY 2022. [DOI: 10.1071/am20024] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Free-ranging koalas generally feed at night; however, captive koalas are usually fed during the day in order to encourage activity for display purposes. We studied the temporal effect of feeding on body temperature of captive koalas in Queensland, to determine whether nocturnal feeding may be beneficial for koalas in warmer climates. Six adult koalas were implanted with thermal transmitters and data loggers, waxed together as a single package, to record internal body temperature. Koalas were exposed to two treatments: koalas were fed in the morning (between 0730 and 0830 hours) during the AM treatment or late afternoon (between 1700 and 1800 hours) for the PM treatment. The body temperature of koalas fed in the mornings was on average 0.5°C higher at its peak (P ≤ 0.01) when compared to koalas fed in the evening. Furthermore, the body temperature maxima of morning-fed koalas was reached ~2 h earlier in the afternoon, compared with those fed in the evening. There was no significant difference between behaviours associated with the two feeding regimes: inactivity (P = 0.840), feeding (P = 0.472) and activity (P = 0.634). We postulate that nocturnal feeding by koalas may be an adaptive mechanism that reduces diurnal heat load during times of high environmental temperatures.
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Okrouhlík J, Šumbera R, Gardner B, Schoemann K, Lövy M, Bennett NC. Are southern African solitary mole-rats homeothermic or heterothermic under natural field conditions? J Therm Biol 2020; 95:102810. [PMID: 33454040 DOI: 10.1016/j.jtherbio.2020.102810] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/08/2020] [Accepted: 12/12/2020] [Indexed: 10/22/2022]
Abstract
Abandoning of a stable body temperature (Tb), a phenomenon known as heterothermy, is an adaptation to cope mainly with a lack of food and water, especially in species inhabiting daily or seasonally variable environments. There is increasing evidence that African mammals avoid adverse conditions by heterothermy and eventually by entering torpor. Members of subterranean rodent family, the African mole-rats (Bathyergidae), are suitable candidates to study both phenomena, because of the diversity of their strategies in respect of maintaining stable Tb ranging from homeothermic species to a mammal with the most labile Tb, the naked mole-rat. Currently, there are field data on daily and seasonal Tb in one social species only and such information are lacking for any solitary mole-rat. In our study, we recorded yearly Tb in two solitary bathyergids, the Cape mole-rat Georychus capensis and the Cape dune mole-rat Bathyergus suillus from South Africa using intraperitoneally implanted dataloggers. Since this region is characterised by changing ecological characteristics, we expected either decreases of Tb within 24 h indicating daily torpor and/or longer-term decreases of Tb, which would indicate multiday torpor. Although we found seasonally phase shifted low amplitude daily Tb cycles, we did not find any remarkable and regular daily and/or seasonal Tb deviations, likely showing an absence of torpor in both species. Due to absence of this energy saving mechanism, we may speculate that both species could be vulnerable to ongoing global climatic change.
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Affiliation(s)
- Jan Okrouhlík
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa; Department of Zoology, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
| | - Radim Šumbera
- Department of Zoology, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic.
| | - Brett Gardner
- Werribee Open Range Zoo, Veterinary Hospital, Zoos Victoria, K Road, Werribee, Victoria, 3029, Australia
| | - Keegan Schoemann
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Matěj Lövy
- Department of Zoology, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
| | - Nigel Charles Bennett
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
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Friend T, Corsini G, Manero V, Cocco R. Diurnal Body Temperature and Rate of Passage of Loggers in Lions. Animals (Basel) 2020; 10:ani10081388. [PMID: 32796500 PMCID: PMC7459775 DOI: 10.3390/ani10081388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 07/30/2020] [Accepted: 08/06/2020] [Indexed: 11/16/2022] Open
Abstract
Simple Summary It is assumed that all mammals have circadian rhythms in their body temperatures, but that has never been described in African lions. The disruption of circadian rhythms can indicate poor animal welfare. Thirteen miniature temperature data loggers were fed to 11 lions, and reliable data were obtained for seven of the lions. Finding the small loggers after they passed through the lions was a challenge because the lions could move between their bedded and heated dens and an outside exercise area. The loggers passed through the lions in an average of 22 h, so future research using the non-invasive method of feeding temperature loggers is limited to that time frame. A highly significant diurnal pattern in body temperature was found, with temperatures being 1.14 °C higher in the afternoon than in the morning. Hence, alteration of body temperature rhythm could be useful in assessments of animal welfare. Abstract The documentation of diurnal patterns in body temperature in lions could be important because disruption of circadian patterns can be a useful measure of distress. This study quantified changes in body temperature of seven African lions (Panthera leo) at 5 min intervals during cold conditions from noon until the ingested body temperature loggers were expelled the next day. Thirteen loggers were fed to 11 lions during their daily noon feeding, while ambient temperatures were also recorded using six data loggers. The lions had continuous access to their dens and exercise pens during the day but were restricted to their heavily bedded dens that also contained a heat lamp from 23:00 until 08:00 the next day. Body temperatures averaged 37.95 ± 0.42 °C at 15:50, and 36.81 ± 0.17 °C at 06:50 the next day, 30 min before the first loggers passed from a lion, and were significantly different (t-test, t = 8.09, df = 6, p < 0.0003). The mean duration for the time of passage was 22 ± 2.69 (h ± SD), so future studies using the noninvasive feeding of temperature loggers need to consider that time frame.
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Affiliation(s)
- Ted Friend
- Department of Animal Science, Texas A&M University, College Station, 3785 W. Villa Maria Rd., Bryan, TX 77807, USA
- Correspondence: ; Tel.: +1-979-255-3153
| | | | - Vincent Manero
- Independent Researcher, Le Coine, 31352 Agiez, Switzerland;
| | - Raffaella Cocco
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy;
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Adam D, Johnston SD, Beard L, Nicolson V, Gaughan JB, Lisle AT, FitzGibbon S, Barth BJ, Gillett A, Grigg G, Ellis W. Body temperature of free-ranging koalas (Phascolarctos cinereus) in south-east Queensland. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2020; 64:1305-1318. [PMID: 32388686 DOI: 10.1007/s00484-020-01907-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 02/17/2020] [Accepted: 03/24/2020] [Indexed: 06/11/2023]
Abstract
The distribution of the koala (Phascolarctos cinereus) in Queensland is predicted to contract as a result of climate change, driven by the frequency, intensity and duration of heatwaves and drought. However, little is known about the physiological responses of this species to environmental extremes under field conditions. This study aimed to establish the efficacy of surgically implanted thermal radio transmitters and data loggers to measure the body temperature of free-ranging koalas across a range of environmental conditions and ambient temperatures. Five free-ranging koalas in southeast Queensland were implanted with thermal transmitters and data loggers waxed together as a single package. Body temperatures were recorded for variable periods ranging from 3 to 12 months. Diurnal rhythms in body temperature were detected irrespective of season. The long-term diurnal body temperature peak for all koalas occurred between 16:00 and 17:00 h and body temperature was 36.7-36.9 °C, the long-term nadir occurred between 07:00 and 08:00 h and body temperature was 35.4-35.7 °C. Koala body temperatures as low as 34.2 °C and as high as 39.0 °C were recorded. Thermolability became apparent when ambient temperatures were outside the deduced thermal neutral zone for koalas (14.5-24.5 °C): heat was accumulated during the day and dissipated during the cool of the night. While this study is the first to report on body temperature of free-ranging koalas in their normal behavioural context, further investigations are necessary to determine the physiological boundaries of the thermal niche for this species, in order to better equip models that will more accurately predict the impacts of climate change on koalas.
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Affiliation(s)
- D Adam
- Wildlife Science Unit, School of Agriculture & Food Science, The University of Queensland, Gatton, Queensland, 4343, Australia.
| | - S D Johnston
- Wildlife Science Unit, School of Agriculture & Food Science, The University of Queensland, Gatton, Queensland, 4343, Australia
| | - L Beard
- School of Biological Sciences, The University of Queensland, St Lucia, Queensland, 4067, Australia
| | - V Nicolson
- Dreamworld Veterinary Clinic, Dreamworld, Coomera, Queensland, 4209, Australia
| | - J B Gaughan
- School of Agriculture & Food Sciences, The University of Queensland, Gatton, Queensland, 4343, Australia
| | - A T Lisle
- School of Agriculture & Food Sciences, The University of Queensland, Gatton, Queensland, 4343, Australia
| | - S FitzGibbon
- Koala Ecology Group, School of Agriculture & Food Sciences, The University of Queensland, St Lucia, Queensland, 4067, Australia
| | - B J Barth
- Koala Ecology Group, School of Agriculture & Food Sciences, The University of Queensland, St Lucia, Queensland, 4067, Australia
| | - A Gillett
- Koala Ecology Group, School of Agriculture & Food Sciences, The University of Queensland, St Lucia, Queensland, 4067, Australia
| | - G Grigg
- School of Biological Sciences, The University of Queensland, St Lucia, Queensland, 4067, Australia
| | - W Ellis
- Koala Ecology Group, School of Agriculture & Food Sciences, The University of Queensland, St Lucia, Queensland, 4067, Australia
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Farsi H, Harti D, Achaâban MR, Piro M, Raverot V, Bothorel B, Ouassat M, Challet E, Pévet P, El Allali K. Melatonin rhythm and other outputs of the master circadian clock in the desert goat (Capra hircus) are entrained by daily cycles of ambient temperature. J Pineal Res 2020; 68:e12634. [PMID: 32011000 DOI: 10.1111/jpi.12634] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 02/03/2023]
Abstract
In desert areas, mammals such as camel and goat are exposed to harsh environmental conditions. The ambient temperature (Ta) cycles have been shown to entrain the circadian clock in the camel. In the present work, we assumed that, in the goat living in a desert biotope, Ta cycles would have the same synchronizing effect on the central clock. Therefore, the effects of Ta cycles on body temperature (Tb), locomotor activity (LA) and melatonin (Mel) rhythms as outputs of the master circadian clock have been studied. The study was performed on bucks kept first under constant conditions of total darkness (DD) and constant Ta, then maintained under DD conditions but exposed to Ta cycles with heat period during subjective day and cold period during subjective night. Finally, the Ta cycles were reversed with highest temperatures during the subjective night and the lowest temperatures during the subjective day. Under constant conditions, the circadian rhythms of Tb and LA were free running with an endogenous period of 25.3 and 25.0 hours, respectively. Ta cycles entrained the rhythms of Tb and LA to a period of exactly 24.0 hours; while when reversed, the Ta cycles led to an inversion of Tb and LA rhythms. Similarly, Ta cycles were also able to entrain Mel rhythm, by adjusting its secretion to the cooling phase before and after Ta cycles inversion. All together, these results show that the Ta cycles entrain the master circadian clock in the goat.
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Affiliation(s)
- Hicham Farsi
- Comparative Anatomy Unit, Department of Biological and Pharmaceutical Veterinary Sciences, Hassan II Agronomy and Veterinary Medicine Institute, Rabat, Morocco
| | - Driss Harti
- Comparative Anatomy Unit, Department of Biological and Pharmaceutical Veterinary Sciences, Hassan II Agronomy and Veterinary Medicine Institute, Rabat, Morocco
| | - Mohamed R Achaâban
- Comparative Anatomy Unit, Department of Biological and Pharmaceutical Veterinary Sciences, Hassan II Agronomy and Veterinary Medicine Institute, Rabat, Morocco
| | - Mohammed Piro
- Medicine and Surgical Unit of domestic animals, Department of Medicine, Surgery and reproduction, Hassan II Agronomy and Veterinary Medicine Institute, Rabat, Morocco
| | - Véronique Raverot
- Laboratory of Hormonology, East Center for Biology and Pathology, East Hospital Group, Civil Hospices of Lyon, Lyon, France
| | - Béatrice Bothorel
- Institute of Cellular and Integrative Neurosciences, CNRS and University of Strasbourg, Strasbourg, France
| | - Mohammed Ouassat
- Comparative Anatomy Unit, Department of Biological and Pharmaceutical Veterinary Sciences, Hassan II Agronomy and Veterinary Medicine Institute, Rabat, Morocco
| | - Etienne Challet
- Institute of Cellular and Integrative Neurosciences, CNRS and University of Strasbourg, Strasbourg, France
| | - Paul Pévet
- Institute of Cellular and Integrative Neurosciences, CNRS and University of Strasbourg, Strasbourg, France
| | - Khalid El Allali
- Comparative Anatomy Unit, Department of Biological and Pharmaceutical Veterinary Sciences, Hassan II Agronomy and Veterinary Medicine Institute, Rabat, Morocco
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Downey PMR, Caraguel CGB, Speight N, Fabijan J, Boardman WSJ. Field immobilization using alfaxalone and alfaxalone-medetomidine in free-ranging koalas (Phascolarctos cinereus): a randomized comparative study. Vet Anaesth Analg 2020; 47:368-376. [PMID: 32276883 DOI: 10.1016/j.vaa.2019.10.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 09/10/2019] [Accepted: 10/08/2019] [Indexed: 01/15/2023]
Abstract
OBJECTIVE To characterize and compare two intramuscular drug protocols using alfaxalone and alfaxalone-medetomidine combination for the field immobilization of free-ranging koalas. STUDY DESIGN Blinded, randomized, comparative field study. ANIMALS A total of 66 free-ranging koalas from the Mount Lofty Ranges, South Australia. METHODS Koalas were randomly allocated into two groups. Group A animals were given alfaxalone alone at 3.5 mg kg-1. Group AM animals were given alfaxalone 2 mg kg-1 and medetomidine 40 μg kg-1, reversed with atipamezole at 0.16 mg kg-1. Blinded operators recorded heart rate (HR), respiratory rate (fR), cloacal temperature, depth of sedation and times to: first effect, sedation suitable for clinical interventions, first arousal and full recovery. Data were analysed using independent t test, Mann-Whitney U test, chi-square analysis and log-rank test at 5% level of significance. RESULTS Suitable immobilization for clinical examination and sample collection was achieved in all animals. In groups A and AM, median time to working depth was 6.5 minutes (range: 3.4-15) and 8.1 minutes (range: 4.3-24) and time to complete recovery was 66 minutes (range: 12-138) and 34 minutes (range: 4-84), respectively, following reversal. Time to first effect was significantly shorter in group A (p = 0.013), whereas time to full arousal was significantly shorter in group AM (p = 0.007) probably due to the administration of atipamezole. Maximum HR was 117 ± 28 beats minute-1 in group A, which was a significant increase from baseline values (p < 0.0001), whereas group AM showed a significant tachypnoea of 67 ± 25 (normal fR 10-15; p < 0.0001). CONCLUSIONS AND CLINICAL RELEVANCE Both the protocols produced immobilization, enabling clinical examination and sample collection; however, protocol AM was more suitable for field work due to shorter recovery times.
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Affiliation(s)
- Philip M R Downey
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, Australia
| | - Charles G B Caraguel
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, Australia
| | - Natasha Speight
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, Australia
| | - Jessica Fabijan
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, Australia
| | - Wayne S J Boardman
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, Australia.
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Temperatus® software: A new tool to efficiently manage the massive information generated by iButtons. Int J Med Inform 2019; 126:9-18. [DOI: 10.1016/j.ijmedinf.2019.03.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 12/04/2018] [Accepted: 03/09/2019] [Indexed: 02/06/2023]
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Adam D, Beard L, Johnston SD, Nicolson V, Lisle A, McKinnon A, Larkin R, Theilemann P, Gillett A, Brackin K, FitzGibbon S, Barth B, Ellis W. Recording body temperature in koalas (Phascolarctos cinereus
): a comparison of techniques. Aust Vet J 2018; 96:308-311. [DOI: 10.1111/avj.12719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 02/04/2018] [Accepted: 03/05/2018] [Indexed: 12/01/2022]
Affiliation(s)
- D Adam
- Wildlife Science Unit, School of Agricultural and Food Sciences; The University of Queensland; Gatton Queensland 4343 Australia
| | - L Beard
- Wildlife Science Unit, School of Agricultural and Food Sciences; The University of Queensland; Gatton Queensland 4343 Australia
| | - SD Johnston
- Wildlife Science Unit, School of Agricultural and Food Sciences; The University of Queensland; Gatton Queensland 4343 Australia
| | | | - A Lisle
- Wildlife Science Unit, School of Agricultural and Food Sciences; The University of Queensland; Gatton Queensland 4343 Australia
| | - A McKinnon
- Moggill Koala Hospital; Department of Environment Heritage and Protection; Moggill QLD Australia
| | - R Larkin
- Moggill Koala Hospital; Department of Environment Heritage and Protection; Moggill QLD Australia
| | - P Theilemann
- Moggill Koala Hospital; Department of Environment Heritage and Protection; Moggill QLD Australia
| | - A Gillett
- Australia Zoo Wildlife Hospital; Beerwah QLD Australia
| | - K Brackin
- Bellbowrie Veterinary Surgery; Bellbowrie QLD Australia
| | - S FitzGibbon
- Koala Ecology Group, School of Agriculture & Food Sciences; The University of Queensland; St Lucia QLD Australia
| | - B Barth
- Koala Ecology Group, School of Agriculture & Food Sciences; The University of Queensland; St Lucia QLD Australia
| | - W Ellis
- Koala Ecology Group, School of Agriculture & Food Sciences; The University of Queensland; St Lucia QLD Australia
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Cabral L. In this issue - January/February 2016. Aust Vet J 2016. [DOI: 10.1111/avj.12410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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