Characteristics of occupied nests Cory’s shearwater Calonectris borealis (Cory, 1881) in the Central Group of islands, Azores, during the breeding season 2025

Despite its ecological importance, there remains a lack of high-resolution, standardized data regarding the characterization of their breeding habitats, which are increasingly threatened by habitat degradation, invasive predators, and climate change.

This data set addresses this knowledge gap by presenting a comprehensive data package characterizing 421 active nests across 11 colonies on four islands of the Central Group: Faial, Graciosa, Pico, and Terceira. The sampling was conducted between 30 April and 10 October of 2025. The dataset is organized into two primary components: 1) a physical characterization involving numerical variables (such as nest depth, entrance dimensions, internal width, altitude, slope, and proximity to the sea and to human infrastructure) as well as categorical variables (such as the type of nests, the substrate found inside the nest and obstacles in front of the nest entrance); and 2) a detailed vegetation survey conducted at each nest using the Braun-Blanquet method.