Leila Siciliano-Martina (EEB student, Light and Lawing Labs) will be defending her dissertation proposal Monday, May 13 at 12:00 pm in WFES 336 and everyone is invited to attend the public portion of the proposal defense.
Her talk title is Unintended Morphological Impacts of Captivity
Summary: The morphological differences that exist between captive and wild populations have been a recurrent theme in scientific literature for at least a century; however, the exact trends, mechanisms, and consequences of these differences are poorly understood. My dissertation research will address some of the long-standing questions and hypotheses associated with captive morphology by conducting meta-analyses on previously published data and using geometric morphometric techniques on newly acquired cranial and mandibular photographs of captive, wild, and reintroduced canids. Although the morphology of captive populations seems to shift in predictable ways, these trends have yet to be examined using a thorough, quantitative approach. By conducting a meta-analysis, this research will address whether captive animals show predictably distinct morphology and whether those changes are impacted by lifestyle covariates shared across species. Preliminary results suggest that cranial measures differ significantly between captive and wild populations of several mammalian orders, although the magnitude and direction of the changes appears to vary with taxonomy and diet. Similarly, by examining the nature, magnitude, and directionality of morphological shifts that occur over captive generations among different canid species, my research will further illuminate the ways in which captive populations change, the key predictors of these morphological shifts, the number of captive generations required for changes to become apparent, and any driving mechanisms. For example, previous studies have shown that the morphology of captive carnivorans differs in cranial regions strongly associated with bite force, which could have significant implications for the success of captively-bred reintroduced animals. Initial results regarding the Mexican wolf (Canis lupus baileyi) suggest that the cranial morphology of historic wild populations differs significantly from both captive and reintroduced populations in cranial regions associated with bite force. To further examine the functional differentiation of captive populations, my research will also estimate bite force and evaluate dietary differences between wild and reintroduced populations. Understanding how species change in captivity can help predict the challenges facing reintroduction efforts and the ways captive management should be altered to help mitigate those effects. By documenting the differentiation of wild and captive animals, the findings of this study will provide commentary on the controversies associated with captive reintroductions and test a number of the long-standing hypotheses associated with the morphological differentiation of captive populations.