Chameleons are an understudied taxon facing many threats, including collection for the international pet trade and habitat loss and fragmentation. A recent field study reports a highly female-biased sex ratio in the Eastern Arc Endemic Usambara three horned chameleon, Trioceros deremensis, a large, sexually dimorphic species. This species is collected for the pet trade, and local collectors report males bring a higher price because only this sex has horns. Thus, sex ratios may vary due to differential rates of survival or harvesting. Alternatively, they may simply appear to be skewed if differences in habitat use biases detection of the sexes. Another threat facing chameleons is that of habitat loss and fragmentation. Despite enormous amounts of research, the factors of fragmentation that different species respond to is still under debate. Understanding these responses is important for current mitigation efforts as well as predicting how species will respond to future habitat alteration and climate change. My study suggests that differences in survival and detection may explain much of the observed seasonal sex skew in adult T. deremensis. Within fragmented habitat chameleons consistently responded more to edge effects and vegetative characteristics associated with fragmentation than to area or isolation effects. This may bode poorly for chameleon populations in the coming decades as climate change further alters vegetative communities and exacerbates edge effects.
| Identifer | oai:union.ndltd.org:vcu.edu/oai:scholarscompass.vcu.edu:etd-1389 |
| Date | 25 July 2012 |
| Creators | Shirk, Philip |
| Publisher | VCU Scholars Compass |
| Source Sets | Virginia Commonwealth University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Theses and Dissertations |
| Rights | © The Author |
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