Date of Award

Spring 5-1-2005

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Life Sciences

First Advisor

George S. Bakken

Second Advisor

Michael J. Angilletta

Third Advisor

Steven L. Lima

Abstract

Water birds whose young begin swimming while downy are interesting because hypothermia and mortality are associated with wetting. Wetting is known to increase heat loss, but little is known about the amount of heat lost to air vs. water during swimming. Accurate measurements of body temperature are required in studies investigating heat loss. I used 2-d to 3-d-old mallard ducklings (Anas platyrhynchos) to test whether remote thermographic measurement of scalp temperature could be used to estimate core temperature from a distance. For wind speeds of up to 2.5 mis, I found cloaca} temperature could be estimated to within 1 °C by using a regression model incorporating only scalp temperature and ambient temperature. This method allowed non-invasive measurement of body temperature, thus minimizing stress associated with traditional techniques that may alter behavior patterns and physiological parameters. To partition heat loss to air and water, I tested 2 -3d old mallard ducklings swimming under different combinations of air and water temperature. Heat loss from ducklings with dry down to air and water was partitioned by fitting data to a heat transfer model of the form M = G (Tb - Tw) + Ke(Tb - T3). Thermal conductance to water increased with water temperature, while thermal conductance to air remained constant. It has been suggested that the majority of heat loss to the water is from the legs and that amount of heat flow through waterfowl's legs can be altered. To test this, we measured heat loss through the legs and feet of 3-4d old mallard ducklings using an adiabatic calorimeter. Ducklings increased thermal conductance of their legs and feet with increasing heat stress. , I t t I Ducklings are capable of altering the amount of heat flow through their legs and feet, however the majority of heat loss occurs through the ventral down area in contact with the water.

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