Assessing Welfare of Armadillos Using Hormonal & Foraging Indicators, and Patch Use in Argentinean Birds
thesisposted on 13.12.2012, 00:00 authored by Jennifer A. Howell-Stephens
This dissertation explores aspects of endocrinology and foraging ecology to study the hormone profiles and well-being of zoo-housed three-banded armadillos (Tolypeutes matacus). It also uses foraging ecology to study foraging behavior in a seed-eating bird community in Argentina. Though the subjects may seem different, understanding how animals perceive and react to their environments is a common theme. Chapter 1 describes my journey to and through the dissertation, as I tackled my lab work, and broke free from my fear of field work. It also reflects my beliefs and personal goals for my post-doctorate career. Chapter 2 describes the characterization of the gonadal hormone activity of the zoo-housed three-banded armadillo. Non-invasive fecal hormone analysis was used to evaluate the fecal progestagen metabolites in females’ samples and fecal androgen metabolites in males’ samples using enzyme immunoassays. The third chapter describes the characterization of the adrenocortical activity of the zoo-housed three-banded armadillo. An adrenocorticotropic hormone (ACTH) challenge was conducted (1 male, 1 female) to validate the physiological response of elevated adrenocortical activity expected from an increase in ACTH. Biological events (aggressive pairing, copulation, pregnancy, veterinary procedures) validated the biological elevation of adrenocortical activity in response to a stressor. A longitudinal study of the adrenocortical activity of male and female armadillos was also conducted. Chapter 4 examines the integration of evaluating the adrenocortical activity and foraging behavior in zoo-housed armadillos to determine how they perceive their environment to assess their well-being. Foraging patches were used to quantify foraging intensity (giving-up densities, GUDs) of armadillos within three patch treatments (varying substrate quantity, patch quality and bedding amount). Non-invasive fecal hormone analysis was used to evaluate the fecal glucocorticoid metabolites (FGM) in male and female samples using enzyme immunoassays. The fifth chapter addresses the foraging behavior of a seed-eating bird community in Argentina. The work supports the idea that birds are major seed consumers in South America and may out-compete rodents for seeds in these communities. Giving-up densities were measured to evaluate bird’s foraging preferences. Camera traps allowed for the identification of species that foraged from food patches, along with their spatial and temporal patterns.