Foraging habitats of the seabird community of Europa Island (Mozambique Channel)

Original provider:
Sebastien Jaquemet

Dataset credits:
Sebastien Jaquemet

Abstract:
We investigated the foraging habitats of the
winter breeding community of tropical seabirds from
Europa Island (Mozambique Channel) in September
2003. We focused our study on the dominant species of
this austral community, the sooty tern (<i>Sterna fuscata</i>),
the red-footed booby (<i>Sula sula</i>), and the frigatebirds,
including the great (<i>Fregata minor</i>) and the lesser frigatebirds (<i>F. ariel</i>). We considered the at-sea distribution and abundance of these species in relation to
chlorophyll concentration, sea surface temperatures,
sea surface height anomalies, depth of the thermocline,
distance to the colony, and presence of surface marine
predators, flying fishes and other seabirds. Although the
marine environment where seabirds foraged was oligotrophic,
it presents the best feeding opportunities for
seabirds for the area in winter.<br><br>
Our study demonstrates
that the winter-breeding seabird species of Europa Island
tend to forage in productive waters in association
with other marine predators when possible. Sooty terns
and frigatebirds were widely distributed in the whole
study area, whereas red-footed boobies were not found
farther than 160 km from their colonies and were associated
with relatively productive waters. Sooty terns and
red-footed boobies were aggregated where flying fishes
were abundant. The presence of other marine predators
was associated with larger multispecies feeding flocks
than when no association occurred. Sooty terns, which
are numerically dominant at Europa and adopted network
foraging, seem to be catalysts of feeding events, and represented a good target for the other foraging
species, especially frigatebirds. However, when possible,
frigatebirds favor association with flocks of red-footed
boobies.