Date of Award


Publication Type

Master Thesis

Degree Name



Great Lakes Institute for Environmental Research


Drouillard, Ken G.


Health and environmental sciences, Intraperitoneal injection, Metabolism, Physiologicaltolerance, Polychlorinated biphenyls, Respirometry




The dawn chorus is a bout of increased song output performed by birds prior to sunrise during the breeding season. Although nearly ubiquitous among avian species, the dawn chorus is poorly understood compared to daytime song. Little is known about how extrinsic variables influence dawn chorus performance. In this thesis, I measured relationships between dawn chorus start times and moon brightness, cloud cover, precipitation, ambient temperature, and artificial light exposure in a community of north temperate birds. I found that birds begin their dawn choruses significantly earlier with increasing moon brightness and ambient temperature, and significantly later with presence of cloud cover and precipitation. I found no significant changes in dawn chorus start times when birds were exposed to short-term overnight artificial lighting. This research serves as the first comprehensive study of the effects of extrinsic factors on dawn chorus start times in north temperate birds.