Date of Award

4-6-2018

Document Type

Honors Thesis

Department

Mathematics

First Advisor

Shandelle M. Henson

Abstract

Protection Island, Washington hosts a large colony of Glaucous-winged gulls (Larus glaucescens). These birds are known to exhibit every-other-day egg-laying synchrony in dense areas of the colony in response to egg cannibalism, which is the main source of egg loss. Here we present an equilibrium analysis of a discrete-time animal behavior model for egg laying. We use Jury Conditions to find the stability criteria for the equilibrium as a function of the colony density and show that a 2-cycle bifurcation occurs when the equilibrium loses stability. The 2-cycle pattern in egg laying becomes increasingly synchronous as the colony density increases. We also show that egg-laying synchrony benefits the colony by allowing more eggs to survive cannibalism.

Subject Area

Glaucous-winged gull; Sea birds--Eggs; Sea birds--Behavior; Protection Island (Wash.)

Creative Commons License

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

Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS