Blog by Dr Steffen Oppel, Senior Conservation Scientist, RSPB Centre for Conservation Science

Satellite telemetry has revealed a new travel route of an Ascension frigatebird through Brazilian seas. This is the first time this species has been recorded in the Americas and shows there is still much to learn about this tropical ocean wanderer that breeds only on the UK Overseas Territory of Ascension.

Unusual track leads to new recording of Ascension frigatebird

Most birdwatchers have to make substantial sacrifices to record new or unusual sightings, especially when they are interested in pelagic seabirds. Braving howling winds, cold temperatures, or driving rain is the typical treat for anybody interested in seeing a pelagic rarity from the coast. Add seasickness for those venturing out onto the ocean. In the age of modern technology that could become a thing of the past: Sean Williams, a PhD student at Michigan State University, saw an unusual track in an online database, and quickly realized that the Ascension frigatebird – a tropical ocean wanderer that breeds only on the UK Overseas Territory of Ascension – had never been recorded before in the Americas.

Sean contacted the Ascension Island Government and the RSPB, who were both tracking Ascension frigatebirds in 2013 and 2014 to better understand their distribution at sea and to inform marine spatial planning around Ascension. The scientists on Ascension and at the RSPB inspected the data of a juvenile bird a bit closer, and confirmed that the bird had indeed flown through Brazilian waters in June and July 2014 as part of a >12,000 km journey across the Atlantic Ocean.

Photo: A juvenile Ascension frigatebird equipped with a satellite transmitter by the Ascension Island Government Conservation Department

Evidence of an immense journey

Although nobody in Brazil had the fortune to actually see the bird – it only approached to within about 80 km of some offshore islets – the tracking data reveal exciting new information about the enormous journeys that frigatebirds undertake. The record was accepted by the American Ornithologist’s Union and published in a recent short note.

Ascension frigatebird sightings possible from UK coastline

While such records are very useful for science and conservation efforts that influence marine spatial planning, the joy of actually watching seabirds soar over crashing waves and effortlessly fly through fierce storms is something everybody should experience to appreciate the enormous journeys many of these birds undertake. Why not take a trip to any of the RSPB reserves along the coast (e.g. The Skerries, South Stack, The Oa, Ramsey Island, Bempton Cliffs) – after all it would not be the first time an Ascension frigatebird shows up in the UK, with a previous unusual appearance on Islay in 2013.

This work was funded by the Darwin Initiative through Project 19-026 with logistical support from the Ascension Island Government.

Williams SM, Weber SB, Oppel S, Leat EHK, Sommerfeld J, Godley BJ, Weber N, Broderick AC (2017) Satellite telemetry reveals the first record of the Ascension Frigatebird (Fregata aquila) for the Americas. Wilson Journal of Ornithology 129:600-604

Photo: Journey of a satellite-tracked Ascension frigatebird between June and July 2014, showing that the bird entered Brazilian waters three times during an extended journey across the Atlantic Ocean. The exclusive economic zones of Brazil and African countries are shown in light grey.