Identification and Distribution of the Brown and Cocos Boobies and Their Subspecies

Research identifies five distinct taxa within the Brown–Cocos Booby complex, distinguishing them through key morphological traits such as head color, underwing covert patterns, iris darkness, culmen concavity, and bill color. These differences vary by sex and subspecies, with male Cocos Boobies exhibiting unique white neck markings that help identify subspecies in the Revillagigedo Islands. The study analyzed 50 museum specimens and 754 living birds from 47 locations, providing critical insights for field identification and tracking population movements under environmental changes.

VANDERWERF, E. A. (2025). IDENTIFICATION AND DISTRIBUTION OF THE BROWN AND COCOS BOOBIES AND THEIR SUBSPECIES. Western Birds, 56(3), 176–199. https://doi.org/10.21199/wb56.3.2