Spatial and temporal trends of waterbirds on the Arctic Coastal Plain, Alaska, using generalized additive models: data release

This zip folder contains products that describe density of waterbirds across the Arctic Coastal Plain, Alaska, from 2007 to 2025 based on applying generalized additive models to aerial survey data. See the file `Readme.html` for a complete description of contents. Within are various types of objects for each species: an R model object (.RDS) that contains the best fitting GAM model, an `.html` document that summarizes the GAM model and displays model diagnostics, a multilayer Geotiff raster file of density predictions over the ACP, a geographic vector object that defines the survey area polygon as a Geopackage file, figures of the average density, a figure of the 'relative importance to waterbirds' based average density for 20 species over the entire modeled area, and a raster file of this summarized density. This image is meant to index the relative importance of locations to waterbirds across the survey area as in [Figure 9](https://www.ace-eco.org/vol14/iss1/art18/figure9.html) of Amundson et al. (2019). For detail description of this project, see the GitHub repository https://github.com/USFWS/ACP-Mapping.