multi-species frog occupancy

Anurans (frogs and toads) were surveyed using aural call surveys across the upper Midwest, United States from 2003 to 2008, and again in 2024. This code analyzes these data (from the associated data releases) using a multi-species occupancy model with imperfect detection, species traits, and species associations. It tests for relationships between covariates, occupancy, and detection, and tests for changes through time as well.