UW Aquatic & Fishery Sciences Quantitative Seminar

James Thorson

Northwest Fisheries Science Center, NMFS/NOAA

Two case-studies showing the broad applicability of state-space models for count data

Abstract

Since 2003, state-space demographic models have been used to analyze count and presence-absence data at a landscape level. These ‘occupancy models’ have been used to address questions regarding habitat-selection, environmental changes, long-term population trends, and community composition in terrestrial systems, but are rarely used for aquatic ecology. We therefore adapt a recent model by Dail and Madsen (2011) for aqautic settings, using stage-structured information for salamanders and citizen-science data for groupers. The salamander case-study shows that count data can, in isolation, reconstruct stage-structured demographic rates such as survival, recruitment, and immigration, while the grouper analysis shows that widely available citizen-science data can recover habitat preferences at a broad spatial scale. We conclude by recommending areas of future research regarding state-space models for count data, and predict that this class of models will be broadly useful in terrestrial, aquatic, and natural-resource ecology.