Cranial Responses to Captivity in Lemur Catta and Propithecus Verreauxi in Natural History Museum Collections

Selvey, Hannah Rachel

Graduate Thesis Or Dissertation

Cranial Responses to Captivity in Lemur Catta and Propithecus Verreauxi in Natural History Museum Collections Public Deposited

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Citeable URL: https://scholar.colorado.edu/concern/graduate_thesis_or_dissertations/cj82k773g

Abstract

Captive animals demonstrate a number of differences compared to their wild counterparts, with the suite of some of the most common, and arguably deleterious, referred to collectively as domestication syndrome. Scholars have proposed a number of different variables and mechanisms for the changes, with captive diet being one of the prominent explanations. This thesis explores the effects of captivity on the skulls and mandibles of Malagasy lemurs (predominantly ring-tailed lemurs Lemur catta) using relative linear measurements and selected ratios, gathered from natural history museum collections. I predicted that captive and wild individuals would show differences in cranial measurements related to mastication, which would be driven by their different diets and the exploitation of the kily fruit Tamarindus indica (H1_A). I also predicted that wild individuals would show more overall variation due to consumption of broader, less consistent diets (H1_B). Finally, I predicted that a multivariate model would be able to properly predict captivity status in Lemur catta using linear variables. Captive Lemur catta showed significantly (p=0.0126) shorter relative post-palatal lengths than their wild counterparts, supporting H1_A, and significantly (p=0.0374) smaller variance in the inio-orbital (post-facial) region, supporting H1_B. However, captive individuals showed significantly (p=0.0390) greater variance in anterior flexion of the angular process, which refuted H1_B. A step-wise discriminant function model was able to properly predict captivity status in a sample of n=18 Lemur catta using four linear variables (R²=0.9336). Descriptive statistics across sex and other lemur species revealed differences that should be noted by scholars, specifically significantly (p=0.0250) longer alveo-orbital AO (pre-facial) regions in male Lemur catta. The findings of this thesis, including its critique of physical and intellectual conservation of data, should be taken into account by museum professionals, animal husbandry personnel, and morphologists alike, and all measurements and findings shall be published on open access servers.

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