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The relationship between body and environmental temperatures in savanna elephants, Loxodonta africana
Dissertation (MSc)--University of Pretoria, 2015.
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| Other Authors: | |
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2015
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| _version_ | 1867613610260299777 |
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| access_status_str | Open Access |
| author2 | Van Aarde, Rudi J. |
| author_browse | Van Aarde, Rudi J. |
| author_facet | Van Aarde, Rudi J. |
| collection | Thesis |
| dc_rights_str_mv | © 2015 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MSc)--University of Pretoria, 2015. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/46218 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:38:53.005Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2015 |
| publishDateRange | 2015 |
| publishDateSort | 2015 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/46218 The relationship between body and environmental temperatures in savanna elephants, Loxodonta africana Van Aarde, Rudi J. Fuller, Andrea Mitchell, Duncan Rodrigues D' Araujo, Shaun UCTD Dissertation (MSc)--University of Pretoria, 2015. As a result of climate change, environmental temperatures across southern Africa are predicted to rise by up to 5˚C by 2070. Elephants may be particularly vulnerable to these changes. Their small surface area to mass ratio and lack of sweat glands may impair heat loss. However, it is not known how elephants respond to high environmental temperatures (above 35˚C), limiting our ability to predict the responses of elephants to climate change. My study assessed these responses for the first time. Using an infrared thermal camera and ingestible thermometers, I recorded skin (at 10-minute intervals) and core temperature (at 5-minute intervals) in seven tame, free-ranging elephants. At the same time, I recorded environmental temperature (at 5-minute intervals) using a portable weather station. I expected skin temperature to increase with environmental temperature and to decrease when elephants moved into shade or wet their skin with mud or water. Because of these behavioural changes, I expected that core temperature would not increase with environmental temperature. I expected that if elephants use heterothermy, core temperature range would increase with environmental temperature range and maximum environmental temperature. I also expected that maximum core temperature would increase, and minimum core temperature would decrease with maximum environmental temperature. I found that skin temperature increased with environmental temperature (P<0.0001, generalized additive mixed model), and decreased when elephants were in shade (P<0.0001) or were wet (P<0.0001). Core temperature did not increase with environmental temperature (P=0.54), but increased with time of day (P<0.0001). Furthermore, core temperature range did not increase with environmental temperature range (𝛽=0.003, P=0.83, generalized linear mixed model) or maximum environmental temperature (𝛽=-0.01, P=0.59). Maximum core temperature did not increase (𝛽=0.01, P=0.45) and minimum core temperature did not decrease (𝛽=0.02, P=0.09) with maximum environmental temperature. I conclude that changes in behaviour, which decrease skin temperature, can assist elephants to maintain homeothermy. My findings show that in the heat, elephants maintain core temperature within a narrow range of 2˚C through behavioural changes, which reduce heat gain. I therefore suggest that elephants will be more likely to cope with the direct effects of climate change than not, provided shade and water are available. tm2015 Zoology and Entomology MSc Unrestricted 2015-07-02T11:07:19Z 2015-07-02T11:07:19Z 2015/04/22 2015 Dissertation Rodrigues D' Araujo, S 2015, The relationship between body and environmental temperatures in savanna elephants, Loxodonta africana, MSc Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/46218> A2015 http://hdl.handle.net/2263/46218 en © 2015 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | UCTD The relationship between body and environmental temperatures in savanna elephants, Loxodonta africana |
| title | The relationship between body and environmental temperatures in savanna elephants, Loxodonta africana |
| title_full | The relationship between body and environmental temperatures in savanna elephants, Loxodonta africana |
| title_fullStr | The relationship between body and environmental temperatures in savanna elephants, Loxodonta africana |
| title_full_unstemmed | The relationship between body and environmental temperatures in savanna elephants, Loxodonta africana |
| title_short | The relationship between body and environmental temperatures in savanna elephants, Loxodonta africana |
| title_sort | relationship between body and environmental temperatures in savanna elephants loxodonta africana |
| topic | UCTD |
| url | http://hdl.handle.net/2263/46218 |