Bertarelli-Annual-Report-2024-LR - Flipbook - Page 15
Projects
Marine Science 2023
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Sooty Terns on Parasol Island © Malcolm Nicoll
Seabird Connectivity
Lead Investigators: Dr. Malcolm Nicoll, Zoological Society
of London, Dr. Matthieu le Corre, Université de La Réunion
and Dr. Steve Votier, Heriot-Watt University
This multi-team project is working to understand
connectivity among seabird communities at the scale of
the Western Indian Ocean, and at a finer scale within the
Chagos Archipelago. The region is globally significant
for breeding seabirds with 30 seabird species from 54
breeding colonies spread across the islands between
the Mascarene channel and the Chagos Archipelago.
This project team focuses their research on five key
species: red-footed booby (Sula sula), sooty tern
(Onychoprion fuscatus), wedge-tailed shearwater
(Ardenna pacifica), tropical shearwater (Puffinnus
bailloni), and greater frigatebird (Fregata minor).
In 2023 the team conducted fieldwork in New
Caledonia, Tromelin Island, Round Island, La Réunion,
Rodrigues and Madagascar working with partners
from the Mauritius Wildlife Foundation Rodrigues,
Forestry Rodrigues and The Mauritian National
Parks and Conservation Service. Other partners
have contributed samples for analysis from Aldabra,
Australia, and Hawaii.
Data on red-footed booby ecology were submitted to
the Seychelles Conservation and Climate Adaptation
Trust (SeyCCAT) for the Seychelles Marine Spatial Plan,
a national planning tool.
Using the tropical shearwater as a case study, the
team have been trying to quantify the level of gene
flow among seabird colonies to understand how that
relates to the distribution of several sub-species across
the region. The genetic grouping of populations and
sub-species into clusters provide useful data for making
informed decisions about units of conservation across
large spatial areas.
In the Chagos Archipelago, the team are using the redfooted booby as a case study to identify mechanisms
that facilitate seabird dispersal. Fieldwork done from
a camp on Nelson Island in 2023 adds to a substantial
data set that is starting to explain what factors drive
seabird movement, and how and where the birds
disperse. Tracking data of bird movements when
foraging at sea show a high degree of segregation of
foraging grounds between the different colonies. It
also suggests little to no migratory connection with
colonies outside of the protected area around the
archipelago, with birds largely resident. Within the
islands, however, dispersal is key to connectivity and
recovery, particularly after any rehabilitation of native
habitats such as broad-leaved woodland.
