A Note on Synchronous Egg Laying in a Seabird Behavior Model
During years when sea surface temperature (SST) is high, gulls in a colony on Protection Island, Washington, USA typically experience low food availability. As SST rises, feeder fish follow plankton to cooler temperatures in deeper water levels. Since gulls are surface-feeding birds, they face a food shortage. A tactic male gulls employ to deal with this food shortage is to cannibalize their neighbours' eggs. Gulls in this colony exhibit an adaptive tactic of every-other-day egg-laying synchrony in response to egg cannibalism, and the level of synchrony increases with colony density. Here we analyze the dynamics of an animal behaviour model for egg laying as a function of colony density. As colony density increases, the equilibrium loses stability in a 2-cycle bifurcation. The 2-cycle becomes increasingly synchronous as the colony density continues to increase. We show that egg-laying synchrony benefits the colony in the presence of cannibalism.
Journal of Difference Equations and Applications
Henson, Shandelle; Gallos, Dorothea; Gallos, Christiane; and Watson, Whitney, "A Note on Synchronous Egg Laying in a Seabird Behavior Model" (2018). Faculty Publications. 1038.