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Full-Text Articles in Life Sciences
Habitat Patch Occupancy Dynamics Of Glaucous-Winged Gulls (Larus Glaucescens) Ii: A Continuous-Time Model, Smruti P. Damania, Karl W. Phillips, Shandelle M. Henson, James L. Hayward
Habitat Patch Occupancy Dynamics Of Glaucous-Winged Gulls (Larus Glaucescens) Ii: A Continuous-Time Model, Smruti P. Damania, Karl W. Phillips, Shandelle M. Henson, James L. Hayward
Faculty Publications
The diurnal distribution and abundance dynamics of loafing Glaucous-winged Gulls (Larus glaucescens) were examined at Protection Island National Wildlife Refuge, Strait of Juan de Fuca, Washington. Asynchronous movement of gulls among three habitat patches dedicated to loafing was modeled as a function of environmental variables using differential equations. Multiple time scale analysis led to the derivation of algebraic models for habitat patch occupancy dynamics. The models were parameterized with hourly census data collected from each habitat patch, and the resulting model predictions were compared with observed census data. A four-compartment model explained 41% of the variability in the data. Models …
Habitat Patch Occupancy Dynamics Of Glaucous-Winged Gulls (Larus Glaucescens) I: A Discrete-Time Model, Karl W. Phillips, Smruti P. Damania, James L. Hayward, Shandelle M. Henson, Clara J. Logan
Habitat Patch Occupancy Dynamics Of Glaucous-Winged Gulls (Larus Glaucescens) I: A Discrete-Time Model, Karl W. Phillips, Smruti P. Damania, James L. Hayward, Shandelle M. Henson, Clara J. Logan
Faculty Publications
Diurnal habitat occupancy dynamics of Glaucous-winged Gulls were evaluated in a system of six habitats on and around Protection Island, Washington. Data were collected on the rates of gull movement between habitat patches, and from these data the probabilities of transitions between habitats were estimated as functions of tide height and time of day. A discrete-time matrix model based on the transition probabilities was used to generate habitat occupancy predictions, which were then compared to hourly census data. All model parameters were estimated directly from data rather than through model fitting. The model made reasonable predictions for two of the …