Abundance and distribution of birds from comprehensive surveys of the Canadian Arctic, 1994-2018

Abundance and distribution are critical metrics of population status and foundational information for conservation. However, even these basic metrics have been difficult to obtain for birds in the Canadian Arctic, where costs are high and access is difficult. Here, we present estimates of population size and distribution for 24 species of shorebirds and 37 other species of birds across the Canadian Arctic, using ground-based surveys of 2,528 plots surveyed between 1994 and 2018. Plot locations were selected by stratified random sampling, within wet, moist, or dry habitat categories defined based on satellite remote sensing. Double-sampling was used to determine detection rates and correct the estimates to reflect birds breeding within the plots. Because this was the first large-scale survey effort across Arctic Canada, many of the results provide new insights with conservation implications. Nearly all estimated population sizes for shorebird species exceed prior estimates, many by sever..., , # Abundance and distribution of birds from comprehensive surveys of the Canadian Arctic, 1994-2018

Dataset DOI: [10.5061/dryad.08kprr5fz](10.5061/dryad.08kprr5fz)

## Description of the data and file structure

See Smith et al. (2025) for a complete description of methods. In brief, the study area is all of Arctic Canada (2,629,390 km²) as defined in the Northern Landcover of Canada (NLCC; Olthof 2009, NLCC 2011). The study area is divided into 12 regions, defined by physiographic boundaries, each of which is further subdivided into subregions (32 in total) of a size that can be feasibly surveyed by one helicopter-supported crew in a single year. Each subregion was then split into zones, contiguous areas that included ~12 plots of possibly different habitats. Plots were typically 12 ha (300m x 400m) but were 16 ha (400 m x 400 m) in the early years of the survey. Sampling effort was allocated unevenly among strata (defined as areas of like habitat within subregions), with more plots su...,