Homes for shearwaters
WHEN I tell people I count seabirds I think they imagine I am trying to count the number of birds calling overhead.
More accurately, it usually involves walking along looking among the rocks for nests and eggs. However, for nocturnal burrow nesters, such as Manx Shearwater, a recording of male and female calls is needed to elicit a territorial response from any birds incubating underground. I have employed this technique to count apparently occupied shearwater burrows in the Isles of Scilly for the best part of 20 years now. They can live up to 50 years and like many seabirds are site faithful, so I like to think it’s possible I have been playing my recordings to some of the same birds for nigh on half of both our lives! And no matter how many thousands, or even hundreds of thousands of times I’ve now listened to those loops, the thrill of having a wild bird call back never gets old.
Since rat eradication on St Agnes and Gugh in 2013
14, breeding numbers of shearwaters have increased dramatically and there is evidence of competition for nesting sites as the sub-colonies expand. With the aim of reducing the incidence of hostile burrow takeovers and potentially facilitating recruitment of our ‘home-grown’ chicks, we have recently deployed 35 wooden nestboxes along the east coast of Annet.
Once occupied, these boxes should allow us to easily and safely monitor breeding success. Small infrared cameras in the boxes allow live-streaming of burrow and chick activity. Manx Shearwaters are one of our most important species on Scilly, but their nocturnal behaviour and underground nesting means they are not widely known or engaged with. Through this ‘Homes for Shearwaters’ project we hope to make them more visible and highlight the important work that the Isles of Scilly Wildlife Trust, along with other conservation partners and the community of St Agnes, are doing to support this iconic species with global importance to the UK.