Frigate birds reappear on Ascension Island after 180 year absence

Female Ascension frigatebird sitting on eggs on Ascension Island this week. Credit Derren Fox

December 2012. Two Ascension frigatebirds were spotted sitting on nests on Ascension Island, a UK Overseas Territory. The species has previously been confined to the outlying Boatswain Bird Island, which is just 1km², for decades after taking refuge there when feral cats overran the main island of Ascension.

Millions killed by cats
The seabird population on the tropical UK Overseas Territory, previously numbering into the tens of millions, was devastated by the cats which were introduced onto the island in the early 19th Century to control introduced rats and mice. The RSPB began a project to remove feral cats on Ascension Island in 2002. The project was supported by funding from the Foreign and Commonwealth Office and the island was formally declared feral cat free in 2006.

Globally threatened
The Ascension frigatebird is a globally threatened species found nowhere else in the world. It is one of the 33 Globally Threatened British Birds found in the UK's Overseas Territories, and is considered Vulnerable to Extinction by the IUCN.

Dr Tim Stowe, the RSPB's International Director, said: "This is the news we have been waiting for since starting the project more than a decade ago. Many species on the UK Overseas Territories are threatened by non-native species and this project marks a landmark in conservation. Ascension is the largest, inhabited island where feral cat removal has been attempted and proved successful. What a wonderful Christmas present."

The discovery was made by members of the Army Ornithological Society, together with members of the Ascension Island Government's Conservation Department.

Ascension Frigatebirds
Ascension frigatebirds are sometimes called Man O'War birds or Pirate birds because they steal other birds' food in flight. They are almost as big as albatrosses, and although seabirds, they can't swim.

The adult male Ascension frigatebird is black overall, with a glossy green and purple sheen, but during courtship it develops a bright red gular (a flap of skin) that inflates to form an impressive heart-shaped balloon. The adult female is more rusty-brown, particularly around the collar and breast, and some individuals have patches of white on the breast and abdomen.

Ascension Island birds
Ascension Island is a small, remote, volcanic island in the South Atlantic. It is rich in unique flora and fauna. At the time of its colonisation by Europeans in 1815, it was thought to host 20 million individual seabirds, including the Ascension Frigatebird

Derren Fox from Ascension Island Conservation, said: "We were out with the Army Ornithological Society to work on some other seabirds in the area when Andrew Bray from AOS came up to us with a photograph of the bird on a nest. We were all incredibly excited and went to see the site and survey for further nests in the area. It's a great moment for Ascension conservation and a superb example of collaborative work between the FCO, RSPB and Ascension Island Conservation."

Feral cat eradication
A Foreign and Commonwealth spokesperson, said: "We are delighted at the news that, after almost 180 years, the frigatebirds have returned to Ascension to breed again. The feral cat eradication project has been a real success and we are grateful to the RSPB for their skilful management of the initiative. This is great example of the practical impact of the UK's wider commitment to working with the Territories and environmental partners to protect the bio-diversity of crucial habitats. The UK underlined that commitment with the recent launch of ‘Darwin Plus', a £2m fund to support environmental work across the Territories. We very much hope to see more innovative projects take advantage of this and help further safeguard the extraordinary biodiversity of our Territories."

The project to bring frigate birds back to Ascension Island has been a 10-year collaboration involving the RSPB with Wildlife Management International Ltd, the Ascension Island Government (in particular, seabird restoration fieldworkers: Raymond Benjamin, Adrian Bowers, Darren Roberts, Stedson Stroud, Anselmo Pelembe, Tara Pelembe, Dane Wade, Nathan Fowler, Richard White), many volunteers, the Army Ornithological Society, and Ascension Island Government Environmental Health (Kevin Williams and team for rodent control). Funding for RSPB's work on Ascension has come from the FCO, Defra's Darwin fund, and the European Union.

Female Ascension frigatebird sitting on eggs on Ascension Island this week. Credit Derren Fox