Fig. 1.

Breeding locations of O. castro (circles). Black symbols represent locations with breeding during the Northern Hemisphere hot season; white symbols represent locations with breeding during the Northern Hemisphere cool season; black and white symbols represent locations with sympatric seasonal populations; gray symbol represents protracted (aseasonal) breeding with two seasonal peaks. Archipelago names are in standard type; islands that are mentioned in the text are in parentheses. Baixo and Praia are 5 km apart; Branco and Raso are 7 km apart.