Kris Descovich How do captive wombats cope with extreme environmental seasons? This paper was presented at the 2011 National Wombat Conference

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1 Kris Descovich How do captive wombats cope with extreme environmental seasons? This paper was presented at the 2011 National Wombat Conference National Wombat Conference Sponsored by The Wombat Protection Society

2 Kris Descovich Kris Descovich is a PhD candidate with the University of Queensland. For her PhD programme, she has been working at the Wombat Research Centre, Rockhampton Botanic Gardens and Zoo to investigate issues affecting wombats in captivity, and has looked at a variety of subjects including the effect of environmental temperature, auditory laterality, olfactory enrichment, faecal analysis methodology, and group and enclosure size. Prior to this she completed an honours degree profiling the behaviour of orphaned orangutans in Kalimantan, Indonesia. Kris also volunteers on the National Committee for the Australian Orangutan Project and has extensive experience with domestic and wild animals, having previously worked as a zookeeper, animal attendant and veterinary nurse. Associations: a Rockhampton Botanic Gardens and Zoo, Rockhampton Regional Council, 100 Spencer St, The Range, QLD 4700, Australia b School of Animal Studies, University of Queensland, Gatton, QLD 4343, Australia c Centre for Animal Welfare and Ethics, School of Veterinary Science, University of Queensland, Gatton, QLD 4343, Australia d School of Land, Crop and Food Sciences, University of Queensland, Gatton, QLD 4343, Australia e Wildlife Reproductive Centre, Taronga Western Plains Zoo, Dubbo, 2830 Australia f Dreamworld Veterinary Clinic, Dreamworld Theme Park, Coomera 4209, Australia g Project Kial, PO Box 47, Marlborough 4705, Australia How do captive wombats cope with extreme environmental seasons? Study authors: Descovich, K.A.abc, Lisle, A.d, Johnston, S.b, Keeley, T. e, Nicolson, V.f, Janssen, T. ag, Brooks, P.ag, & Phillips, C.J.C.c The southern hairy-nosed wombat (Lasiorhinus latifrons) relies heavily on denning behaviour to cope with high environmental temperatures. Captive wombats are often required to adjust to foreign environmental conditions with artificial burrows. This study investigated a colony of captive southern hairy-nosed wombats in a sub-tropical environment and whether they experience stress in response to environmental pressures such as season and temperature. Body temperature and faecal corticosterone were measured over six months and were found to be seasonally affected with body temperature highest and corticosterone lowest in winter. Corticosterone and body temperature were positively correlated with each other. Temperature and a combined temperature-humidity index were negatively correlated with corticosterone. Body temperature was unrelated to ambient heat and humidity. Peaks in temperature/humidity did not cause associated peaks in faecal corticosterone. This study indicates that the wombats experienced seasonal fluctuations in body temperature and corticosterone but did not appear to become stressed by increases in temperature and humidity. Wild wombats may differ in response as forage scarcity may enforce longer exposure to ambient conditions Sponsors The Wombat Foundation Saving the Northern Hairy-nosed Wombat

3 How do captive wombats cope with extreme environmental seasons? Kris Descovich BAppSc (hons) with Professor Clive Phillips & Dr Steve Johnston School of Animal Studies & Centre for Animal Welfare and Ethics

4 Poor breeding Large amounts of stress-related behaviour Inappropriate conditions may affect welfare Information on captive populations transferable to wild populations

5 Understanding wombat behaviour Creating conditions that promote captive breeding The relationship between captivity and conservation Reducing the prevalence of stress indicators Today s presentation...

6 Wombats thermoregulate using behaviour (dens, nocturnal behaviour, position, reducing activity) Physiological limit is around 35 C ambient temperature Captive conditions may be inadequate in challenging climates Temperature increase of 6 C is expected within natural range by 2100

7 Body temperature Corticosterone metabolites in faeces Ambient temperature Ambient humidity

8 Determine characteristics of body temperature and if evidence exists for thermal physiological strategies Quantify seasonal patterns of body temperature and corticosterone Investigate relationships between physiology and ambient conditions

9 Adrenal hormone Often produced in response to acute stress In other species it has been used to show heat stress Assists in heat regulation through vasodilation Proteolysis and lipolysis (metabolism of protein and fat) counteracting times of reduced food intake Can be measured non-invasively by measuring hormone metabolites in faeces Measurements taken: Winter (1 month) / Summer (1 month) & 3 additional periods of fluctuating temperature / humidity

10 i buttons - small temperature dataloggers Advantages: Small; long-duration (3 6 months); accurate; nontransmitting so no interference; non-invasive once implanted; positive data exists on their use in other species. Disadvantages: Require implanting and associated risks; nontransmitting so unknown if they fail.

11 I-button Preparation 2 buttons per wombat in case of failure Programmed for hourly data taking Labelled and coated in paraffin / resin mixture Calibrated in a waterbath at 30, 35 and 40 Cleaned with Medizyme Sterilised with OPA Rinsed with sterile water Wombat Preparation Zoletil i/m 100 ( mg/kg) Isoflurorane (1.5 5%) Location Skin preparation (chlorhex, Anti-inflamm. Butorphanol (0.5 mg/kg) Anti-biotic Clavulox (0.5mg/kg) Sutures 2/0 PDS II Recovery, isolated in enclosure No discomfort noticed No infection 2 matings within 1 week Successful parturition

12 Mean: 35.5 C ± 0.5 Mean daily range: 2.1 C ± 0.2 Minimum body temperature recorded was 32.1 C and maximum was 39.9 C Largest range for one individual over entire study was 7 C No evidence of torpor or adaptive heterothermy

13 37.00 Core Body Temperature C hour time

14 60 c 35.7 CORT Faecal corticosterone ng/g A a B C b C C b D Core body temperature C CBT 20 August September October November December January 35.2 Months

15 Calculated using Partial correlations accounting for the strong individual and seasonal differences * Body temperature + ve with corticosterone * * Body temperature no relationship with ambient temp / RH * * Corticosterone ve with ambient temp / RH *

16 1. Wombats, given access to temperature controlled areas and supplemented with food appear to adapt 2. Homeostasis is not compromised when they can escape the heat 3. Wild wombats may respond differently to fluctuating conditions Recommendations for further research: Seasonal patterns of corticosterone in the wild Corticosterone / body temperature / behavioural changes as a result of environmental pressures in the wild

17 i) Wombats will adapt behaviourally where possible before they are affected ii) Several different pressures acting on physiological responses iii) Wild wombats are likely to be affected more significantly than captive wombats iv) Further research is critical due to the potential impacts of climate change

18 The Wombat Foundation Dr Alan Horsup and Andrew Dinwoodie from QLD DERM The Rockhampton Regional Council School of Animal Studies and the Centre for Animal Welfare and Ethics, School of Veterinary Science, University of Queensland Dreamworld s Dr Vere Nicolson Taronga Western Plains Zoo s Tamara Keeley Project Kial s Tina Janssen and Peter Brooks Dedicated wombat volunteers in particular Joel Irwin My supervisors Professor Clive Phillips and Dr Steve Johnston