Using model systems to investigate the effects of captivity on phenotypic variation: implications for captive breeding programmes

Captive breeding programmes (CBPs) offer a method for preventing the extinction of threatened species by assisting with species recovery, primarily by generating animals for reintroduction and supplementing wild populations. However, CBPs often have difficulty establishing self-sustaining populations, unable to maintain consistent reproduction and survivorship in captivity for reintroducing animals back into the wild. A contributing factor leading to this issue may be captive conditions producing phenotypes that differ from wild phenotypes. These phenotypic changes may lead to captive individuals having reduced survivorship, as well as reduced reproductive success, both in captivity and following reintroduction. Ultimately, a range of factors will determine the success of reintroductions; however, the phenotypic changes occurring in captivity, and how this may impact reintroduction success remains largely unknown. In this thesis, I outline how an animal’s phenotype may contribute to the success or failure of CBPs, and in turn, reintroduction success. I used a mammalian and an amphibian species as models to examine phenotypic changes in captivity and specifically looked at developmental, morphological and behavioural phenotypes.