Mahurin Honors College Capstone Experience/Thesis Projects

Department

Biology

Document Type

Thesis

Abstract

In vertebrates, melatonin regulates many components of the circadian rhythm; depending on the organism’s location and time of year, the pineal gland will produce melatonin accordingly, controlling the sleep-wake cycle and breeding physiologies. However, locations at the poles in which the sun is above the horizon for multiple days at a time pose unique challenges for the organisms living there. The goal of this study was to examine how the implantation of melatonin in an arctic-breeding songbird affects its activity levels and circadian rhythm. The subject of this study, the snow bunting (Plectrophenax nivalis), is a small songbird that spends its breeding season in the Arctic, where the sun does not set for months at a time. Fourteen adult male snow buntings were caught in Utqiaġvik, Alaska, to be used in this study. The snow buntings in the treatment group (N=7) were implanted with melatonin, then fitted with accelerometers and housed in an aviary to track their movement patterns over the following 48 hours. Birds in the control group (N=7) underwent the same process, but were given empty implants. The results from the accelerometer data indicate that while the 00:00-04:00 quiescent period of the snow buntings was not affected by melatonin implantation, the overall activity levels of the birds in the treatment group were less dynamic than those of the birds in the control group, implying that higher concentrations of melatonin do affect the birds’ daily movement to some degree.

Advisor(s) or Committee Chair

Noah Ashley, Ph.D.

Disciplines

Biology | Endocrinology | Ornithology | Other Ecology and Evolutionary Biology

Available for download on Friday, April 28, 2023

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