Date of Award:

5-1-1996

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Biology

Committee Chair(s)

James A. Gessaman

Committee

James A. Gessaman

Committee

Edmund D. Brodie Jr.

Committee

LeGrande C. Ellis

Committee

William A. Brindley

Abstract

The change in metabolism of birds exposed to rainfall is poorly understood. I measured the rate of oxygen consumption (VO2) using open-flow respirometry of four male and four female American kestrels (Falco sparverius) during the breeding season at ambient temperatures (Ta) of 5, 10, 15, and 25°C in air without rainfall and then at low (2.5 cm⋅h-1) rainfall and high (6.1 cm⋅h-1) rainfall. Trial order was analyzed as a covariate because kestrel responses appeared to decrease in intensity during the 14-wk study period. The VO2 increased 12.65% at low rainfall while it decreased 0.74% at high rainfall. The rates of oxygen consumption increased more at lower Tas than at higher Tas. Thermal conductance increased 15.51% during low rainfall and increased 3.18% during high rainfall. Thermal conductance increased more at lower Tas than at higher Tas. Body temperatures of the kestrels were significantly lower after exposure to rainfalls at lower Tas than higher Tas, although no kestrel had more than a 3.0°C reduction in body temperature. Body temperatures were 39.49°C after exposure to high rainfall and 39.73°C after low rainfall. More water accumulated in kestrel plumage at higher Tas than at lower Tas, and 5.7 g of water accumulated in the plumage at high rainfall and 2.9 g at low rainfall. Kestrels may remain perched and vigilant at low rainfall whereas at high rainfall kestrels may adopt sleeking behavior and seek shelter to conserve energy. Although my study showed that a male kestrel during the breeding season at 15°C may only increase its total daily energy expenditure by 0.38% per h during a low rainfall, kestrels may experience higher heat losses in natural rainstorms.

Download

Included in

Biology Commons

Share

COinS

Copyright for this work is retained by the student. If you have any questions regarding the inclusion of this work in the Digital Commons, please email us at .