The observed population crash in a colony of sooty terns, tropical seabirds in one of the UK Overseas Territories (UKOTs), is partly due to poor diet, research led by the University of Birmingham has found.
The observed population crash in a colony of sooty terns, tropical seabirds in one of the UK Overseas Territories (UKOTs), is partly due to poor diet, research led by the University of Birmingham has found.
The findings provide fresh evidence of the fragility of marine ecosystems and lend weight to the scientific case for creating the Ascension Island Ocean Sanctuary (AIOS), set to be one of the largest fully protected reserves in the Atlantic Ocean.
The most numerous seabird of tropical waters, sooty terns breed on Ascension Island where the colony is the largest in the entire Atlantic Ocean. The Ascension population has declined in numbers from several million in the middle of the last century, to just a few hundred thousand today. A team based in the University’s School of Biosciences believes the birds’ plight is closely linked to changes in populations of predatory fish such as tuna. The terns follow these large fish across vast expanses of ocean to feed on the small fish driven to the surface as they hunt.
The terns had been expected to benefit from conservation work carried out on the island between 2002 and 2004 by the Royal Society for the Protection of Birds (RSPB). This involved a feral cat eradication scheme in a bid to restore nesting populations of seabird species, including the Ascension frigatebird that is only found on Ascension Island.
Read more at University of Birmingham
Image: Image of adult sooty tern feeding a chick. (Credit: Dawn Osborn)
