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Includes bibliographical references.
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
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Department of Biological Sciences
2014
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| _version_ | 1867613293211811840 |
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| access_status_str | Open Access |
| author | Clarke, Brian Craig |
| author2 | Louw, Gideon |
| author_browse | Clarke, Brian Craig Louw, Gideon |
| author_facet | Louw, Gideon Clarke, Brian Craig |
| author_sort | Clarke, Brian Craig |
| collection | Thesis |
| description | Includes bibliographical references. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/8404 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:33:49.949Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2014 |
| publishDateRange | 2014 |
| publishDateSort | 2014 |
| publisher | Department of Biological Sciences |
| publisherStr | Department of Biological Sciences |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/8404 Water and energy balance in the Namib sand-dune lizard, Angolosaurus skoogi Clarke, Brian Craig Louw, Gideon Nicolson, Sue W Zoology Includes bibliographical references. The field metabolic rate (FMR) and water flux of the herbivorous Namib sand-dune lizard, Angolosaurus skoogi, was measured during the summer non-breeding period (early January) by means of doubly labelled water. FMR was about half that expected for a lizard of this size. Water flux and laboratory measured standard metabolic rates were, however, typical of other desert lizards. It thus appeared a priori that this species was behaviourally reducing metabolic costs through reduced activity. This generated questions with regard to the ecological and physiological significance of low FMRs. Is the reduction forced by intolerable environmental conditions or the need to stay in positive water and energy balance? Alternatively, is activity reduction voluntary and geared towards optimizing growth and storage, possibly in preparation for periods of physiological stress ? The research required to answer these questions forms the basis of this thesis. There has been much discussion about the evolutionary and ecological significance of growth rates. The consensus seems to be that, under most circumstances, animals are adapted in ways that maximize growth or optimize growth in relation to realistically attainable rates of gross energy intake. Animal behaviour may be influenced by factors unrelated to growth considerations such as starvation, involuntary hypo/hyperthermia, predator evasion and social interactions. These factors may be difficult to identify and isolate, making this hypothesis difficult to test. Previous studies on the biology of A. skoogi have shown that this species has a perennially available food source, a wide range of potential body temperatures at its disposal and a low predation risk. Social interaction appear to be confined to the breeding season. This species is thus a particularly suitable subject for a scope for growth optimization study. 2014-10-11T12:21:24Z 2014-10-11T12:21:24Z 1992 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/8404 eng application/pdf Department of Biological Sciences Faculty of Science University of Cape Town |
| spellingShingle | Zoology Clarke, Brian Craig Water and energy balance in the Namib sand-dune lizard, Angolosaurus skoogi |
| thesis_degree_str | Doctoral |
| title | Water and energy balance in the Namib sand-dune lizard, Angolosaurus skoogi |
| title_full | Water and energy balance in the Namib sand-dune lizard, Angolosaurus skoogi |
| title_fullStr | Water and energy balance in the Namib sand-dune lizard, Angolosaurus skoogi |
| title_full_unstemmed | Water and energy balance in the Namib sand-dune lizard, Angolosaurus skoogi |
| title_short | Water and energy balance in the Namib sand-dune lizard, Angolosaurus skoogi |
| title_sort | water and energy balance in the namib sand dune lizard angolosaurus skoogi |
| topic | Zoology |
| url | http://hdl.handle.net/11427/8404 |
| work_keys_str_mv | AT clarkebriancraig waterandenergybalanceinthenamibsanddunelizardangolosaurusskoogi |