Characterizing habitat suitability for a central‐place forager in a dynamic marine environment |
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Authors: | Dana K Briscoe Sabrina Fossette Kylie L Scales Elliott L Hazen Steven J Bograd Sara M Maxwell Elizabeth A McHuron Patrick W Robinson Carey Kuhn Daniel P Costa Larry B Crowder Rebecca L Lewison |
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Institution: | 1. Stanford University, Hopkins Marine Station, Pacific Grove, CA, USA;2. Southwest Fisheries Science Center, Environmental Research Division, National Marine Fisheries Service, National Oceanic and Atmospheric Administration Monterey, Monterey, CA, USA;3. Department of Parks and Wildlife, Kensington, WA, Australia;4. Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA;5. University of the Sunshine Coast, Maroochydore, Qld, Australia;6. Old Dominion University, Norfolk, VA, USA;7. Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA;8. Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, USA;9. Center for Ocean Solutions, Stanford University, Monterey, CA, USA;10. Institute for Ecological Monitoring & Management, San Diego State University, San Diego, CA, USA |
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Abstract: | Characterizing habitat suitability for a marine predator requires an understanding of the environmental heterogeneity and variability over the range in which a population moves during a particular life cycle. Female California sea lions (Zalophus californianus) are central‐place foragers and are particularly constrained while provisioning their young. During this time, habitat selection is a function of prey availability and proximity to the rookery, which has important implications for reproductive and population success. We explore how lactating females may select habitat and respond to environmental variability over broad spatial and temporal scales within the California Current System. We combine near‐real‐time remotely sensed satellite oceanography, animal tracking data (n = 72) from November to February over multiple years (2003–2009) and Generalized Additive Mixed Models (GAMMs) to determine the probability of sea lion occurrence based on environmental covariates. Results indicate that sea lion presence is associated with cool ( <14°C ), productive waters, shallow depths, increased eddy activity, and positive sea‐level anomalies. Predictive habitat maps generated from these biophysical associations suggest winter foraging areas are spatially consistent in the nearshore and offshore environments, except during the 2004–2005 winter, which coincided with an El Niño event. Here, we show how a species distribution model can provide broadscale information on the distribution of female California sea lions during an important life history stage and its implications for population dynamics and spatial management. |
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Keywords: | California current system California sea lion distribution dynamic habitat telemetry
Zalophus californianus
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