Date of Award


Document Type



Environmental and Forest Biology


Incandescent light sources are increasing replaced by other forms of light, such as fluorescent and light-emitting diode (LED) lights, which have greater longevity and offer greater energy efficient. These sources of light differ in more than their cost and efficiency, and have many different physical properties, for instance, their degree of flickering. Low-frequency fluorescent lighting flickers below the critical flickering fusion frequency (CFF) of some birds and may be a source of stress, unlike a non-flickering light source, such as LED. Our study measured levels of glucocorticoid metabolites (GCM’s) in fecal samples of captive European starlings (Sturnus vulgaris ) both across treatments and over a period of days to demonstrate the effects of different forms of light on the stress levels of birds in a laboratory setting. Concentration of GCM’s were not significantly different either across light treatments (P =0.441) or over time (P= 0.209), suggesting flickering properties of low-frequency fluorescent light is not a major source of stress for captive birds over an alternative light source.

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Ornithology Commons