P-37 The Effect of Synchronous Egg-laying on Gull Population Dynamics while Tracking the Egg-laying Order

During years of high sea surface temperature, food resources for glaucous-winged gulls (Larus glaucescens) are scarce. In response, male gulls cannibalize the eggs of neighbors. When this occurs, female gulls in dense areas of the colony adopt a tactic called egg-laying synchrony, in which they lay eggs synchronously on an every-other-day schedule. Field observations show that the first-laid egg of each clutch is the most likely to be cannibalized. We analyzed a mathematical model of egg-laying-behavior that tracks egg-laying order. We found that the system begins to oscillate synchronously when the colony is sufficiently dense. We demonstrated that synchronous colonies produce more eggs than non-synchronous colonies in the presence of cannibalism