- Title
- Foraging behaviour and thermal physiology of Cape sugarbirds: sex-specific responses to temperature
- Creator
- Molepo, Mokgatla Jerry
- Subject
- Sexual dimorphism (Animals)
- Subject
- Sex differences Birds -- Behavior
- Date Issued
- 2017
- Date
- 2017
- Type
- Thesis
- Type
- Masters
- Type
- MSc
- Identifier
- http://hdl.handle.net/10948/19124
- Identifier
- vital:28775
- Description
- Body size (Mb) determines an animal’s energy and water demands for thermoregulation. Sexual dimorphism in Mb is common across many species, but its physiological consequences (e.g. energy and water demands) remain poorly understood. In this study, I determined if the sexually dimorphic Cape Sugarbird (Promerops cafer)–males are up to 15% larger than females, show sex-specific foraging patterns and physiological responses. To determine intraspecific variability behavioural in response to temperature, I compared flower visitation rates between male and female Cape Sugarbirds at different times of the day, and among days that varied in maximum air temperature. A total of 1207 males and 561 females were observed. Female Cape Sugarbirds visited flowers more often and continued to feed especially on hot days. Males generally dominated flower resources throughout the day, except on hot days. I also compared physiological responses in EWL, RMR and Tb between males and females at high air temperatures. There were no significant differences between the two sexes. Aggression which was overlooked appeared to have a high influence on foraging behaviour of Cape Sugarbirds. These results suggest that female Cape Sugarbirds will be more prone to energy and water stress during hot and dry summers in the Fynbos region because of resource dominance by male Cape Sugarbirds. Endemic birds, such as the Cape Sugarbird, warrant a conservation priority, especially since they are the dominant pollinator of the Protea plants in the Fynbos biome. The findings of this study will provide insights into population persistence of Cape Sugarbirds in response to predicted heat waves and rise in global temperatures.
- Format
- iv, 48 leaves
- Format
- Publisher
- Nelson Mandela University
- Publisher
- Faculty of Science
- Language
- English
- Rights
- Nelson Mandela University
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