Spatiotemporal species distribution models of colony census and at-sea survey data for Fratercula cirrhata (Tufted Puffin) and F. corniculata (Horned Puffin) reveal long-term declines in Kodiak, Alask

This repository contains the main datasets analyzed in Stoner et al. (2026).

Included are .csv files with at-sea transect sample and colony count data for Fratercula cirrhata (Tufted Puffins) and F. corniculata (Horned Puffin) from the Kodiak Archipelago, Alaska collected 1975-2022. Prior to processing, raw data were extracted from the North Pacific Pelagic Seabird Database (NPPSD; https://doi.org/10.5066/F7WQ01T3) version 4.1, the North Pacific Seabird Colony Database (NPSCD; https://axiom.seabirds.net/maps/js/seabirds.php?app=north_pacific#z=3&ll=55.00000,-170.00000), and provided by Kodiak National Wildlife Refuge (USFWS). 

Also included are custom user region grids, covariate data, colony strata, and spatial knot file for both at-sea and colony vector autoregressive spatiotemporal (VAST) models. 

The VAST modeling R-script contains model code to run both at-sea and colony models.

Stoner, K. A., R. M. Corcoran, M. L. Arimitsu, J. F. Piatt, and D. E. Lyons (2026). Spatiotemporal species distribution models of colony census and at-sea survey data for Fratercula cirrhata (Tufted Puffin) and F. corniculata (Horned Puffin) reveal long-term declines in Kodiak, Alaska. Ornithological Applications. 128. doi:10.1093/ornithapp/duag053.