Geolocation and immersion loggers reveal adult red-footed boobies are
year-round residents in the tropical Indian Ocean
Abstract
Bio-logging has revealed much about high-latitude seabird migratory
strategies, but tropical species are comparatively understudied. Here we
use geolocators to study the year-round movement behaviour of adult
red-footed boobies (Sula sula rubripes) from the Chagos
Archipelago, tropical Indian Ocean. Light levels suggest that red-footed
boobies are resident in the archipelago year-round, although there are
large latitudinal errors this close to the equator. However, immersion
data revealed tracked birds returned to land year-round, with no
extended at-sea periods, further indicating this population is
non-migratory. Our findings have important implications for seabird
conservation and phylogenetics, as well as for assessing the impact of
seabird nutrients on coral reef ecosystems.