Publication Date

2024

Document Type

Dissertation/Thesis

First Advisor

Irwin, Mitchell T.

Degree Name

M.A. (Master of Arts)

Legacy Department

Department of Anthropology

Abstract

The energetic state of an animal has vital consequences for its fitness, but it can be difficult to detect through behavioral observations. The development of techniques to determine an animals’ energetic state non-invasively would allow conservation planners to rapidly assess the energy balance and conservation potential of individuals, groups, and populations. Thyroid hormones like triiodothyronine (T3) regulate and reflect metabolic state in mammals. T3 is a non-invasive biomarker that can be detected in feces and could potentially be used for this purpose. I perform the first validation of a commercially available T3 radioimmunoassay designed for humans on a wild strepsirrhine population, specifically in wild diademed sifakas (Propithecus diadema). I examined P. diadema energy intakes and T3 levels across habitats and seasons in a highly seasonal environment, the Tsinjoarivo forest, Madagascar in order to validate T3 as a valid marker of these animals’ energetic state. This biological validation is based on prior findings of energetic and nutritional differences between seasons and among habitat types and new data I collected on diet and T3 assays. I collected behavioral and foraging data on 11 individuals across 4 groups varying in habitat quality, to assess correlations between energetic intake (assessed through observation) and metabolic turnover (through T3 assay). I quantified macronutrient nutritional variables that contribute to energy, including fat, available protein, crude fat, sugar, and fiber in samples of food items consumed by sifakas that I collected. I collected fecal samples daily and assayed them to quantify T3 levels. I demonstrate that T3 accurately reflects an animal’s underlying energy balance; with season and sex predicting T3 levels. In a separate model, degree of frugivory was also found to be a significant predictor of T3 concentrations. Therefore, this rapid assessment tool and other, related immunoassays can be deployed throughout Madagascar to assess the energetic vulnerability of sifaka populations in degraded and changing habitats.

Extent

136 pages

Language

en

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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