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Full-Text Articles in Life Sciences
A Note On The Onset Of Synchronous Egg Laying In A Seabird Behavior Model, Dorothea Gallos, Christiane Gallos
A Note On The Onset Of Synchronous Egg Laying In A Seabird Behavior Model, Dorothea Gallos, Christiane Gallos
Honors Theses
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. …
Effects Of Eggshell Coloration On Egg Cannibalism Among Glaucous-Winged Gulls, Isabelle Hwang
Effects Of Eggshell Coloration On Egg Cannibalism Among Glaucous-Winged Gulls, Isabelle Hwang
Honors Theses
A common source of reproductive loss in gulls is egg cannibalism. At a large Glaucous-winged Gull (Larus glaucescens) colony on Protection Island, Washington, cannibalism accounts for 55% of egg loss. Because cannibalism is a form of predation and birds have a highly developed sense of vision, I hypothesized that visible light coloration of Glaucous-winged Gull eggs plays a role in determining whether they are cannibalized. I used logistic regression to test whether egg fate was related to egg brightness, specific coloration, specific spot coverage, coloration relative to the most common coloration, and spot coverage relative to the most common spot …
P-46 A Periodic Matrix Model Of Seabird Behavior And Population Dynamics, Mykhaylo M. Malakhov, Benjamin Macdonald, Shandelle M. Henson, J. M. Cushing
P-46 A Periodic Matrix Model Of Seabird Behavior And Population Dynamics, Mykhaylo M. Malakhov, Benjamin Macdonald, Shandelle M. Henson, J. M. Cushing
Honors Scholars & Undergraduate Research Poster Symposium Programs
Rising sea surface temperatures (SSTs) in the Pacific Northwest lead to food resource reductions for surface-feeding seabirds, and have been correlated with several marked behavioral changes. Namely, higher SSTs are associated with increased egg cannibalism and egg-laying synchrony in the colony. We study the long-term effects of climate change on population dynamics and survival by considering a simplified, cross-season model that incorporates both of these behaviors in addition to density-dependent and environmental effects. We show that cannibalism can lead to backward bifurcations and strong Allee effects, allowing the population to survive at lower resource levels than would be possible otherwise.