Balancing predation and egg harvest in a colonial seabird: A simulation model
Authored by SG Zador, JF Piatt, AE Punt
Date Published: 2006
DOI: 10.1016/j.ecolmodel.2005.11.002
Sponsors:
United States Geological Survey (USGS)
Glacier Bay National Park
Platforms:
R
Model Documentation:
Other Narrative
Model Code URLs:
Model code not found
Abstract
We developed an individual-based model to study the effects of different
regimes of harvesting eggs and natural predation on reproductive success
in a colony of the glaucous-winged gull (Larus glaucescens) in Glacier
Bay National Park, Alaska. The model incorporates the sequence of egg
laying, relaying, and incubation to hatching for individual nests and
calculates hatching success, incubation length, and the total number of
eggs laid (as a result of re-nesting and relaying) in all nests in the
colony. Stochasticity is incorporated in the distribution of nest lay
dates, predation rates, and nests attacked during predation and harvest
events. We estimated parameter values by fitting the model to data
collected at a small colony during 1999 and 2000 using maximum
likelihood. We then simulated harvests and analyzed model predictions.
Model outputs indicate that harvesting early, and at one time, provides
a predictable take of eggs with the least impact to gulls.
Tags
Management
Conservation
Reduction
Populations
Reproductive success
Disturbance
Island
Glaucous-winged gulls
Ring-billed gulls
Larus-glaucescens