Date of Award


Document Type

Honors Thesis



First Advisor

James L. Hayward

Second Advisor

Shandelle M. Henson


Cannibalism leads to a variety of behavioral, demographic, and ecological consequences and is influenced by a range of environmental circumstances among numerous taxa. Although multiple studies have linked cannibalism to egg and chick failure in gull populations, few characterizations of gull cannibal behavior and reproductive success exist. During the 2014 breeding season, we observed the territories of 16 Glaucous-winged Gull (Larus glaucescens) and Glaucous-winged x Western Gull (L. glaucescens x occidentalis) egg cannibal specialists on Protection Island, Washington, USA. We also monitored cannibal foraging behavior, relative reproductive success, and colony-wide egg loss. Cannibal specialists employed a variety of foraging and feeding behaviors and exhibited significantly lower reproductive success than non-cannibals. Future study of the Protection Island gull colony will monitor long-term trends in cannibalistic activity and behavior in relation to environmental change.

Subject Area

Glaucous-winged gull--behavior., Gulls--cannibalism., Cannibalism in animals.

Creative Commons License

Creative Commons Attribution-No Derivative Works 4.0 International License
This work is licensed under a Creative Commons Attribution-No Derivative Works 4.0 International License.

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