Lisa and I spent the morning digging in the first of our Manx shearwater nest boxes. They were built earlier this year by some of our very handy volunteers, Dave Gadd, Geoff Hickman, Steve Bool and Mike Bates. The design is based on those used in NZ that we had the pleasure of seeing first hand last winter – thanks to Shane Cotter who works on Fluttering shearwaters on Matiu / Somes Island in Wellington Harbour and to Lindsay Rowe from the Hutton’s Shearwater Charitable Trust for sharing their designs with us.
We were a bit unsure how easy it would be to dig into our rocky soil so were pleasantly surprised to be able to complete the task without too much swearing! Bracken roots took some shifting but at least we knew the soil was deep in these parts by the very presence of this plant. We are going to put boxes in areas of existing dense shearwater activity, being careful not to disturb any existing natural burrows. This should negate the need to use recordings to call birds in as the real thing should do that job for us. Our birds are currently off the coast of Argentina and won't return until March.
Since the rat eradication project in 1999-2000 our Manx shearwater numbers have quadrupled from under 1000 pairs to nearly 4000 pairs. This gives us a rare opportunity to carry out research on a newly expanding population. Given the difficulty in finding individual nest chambers within the rabbit warrens the birds currently breed in, nest boxes are the next best thing to allow us to establish a study colony. Prior to eradication eggs and chicks were being decimated by the brown rats which arrived on the island via shipwrecks in the 1800's
We plan to carry out GPS tracking work on birds to follow foraging trips plus the boxes will allow us to carry out productivity monitoring work (how many chicks are reared). This will sit nicely with our current research with OxNav involving GLS tracking of birds on migration and our chick ringing programme which is already reaping it’s rewards by showing us that Ramsey born birds are returning to the colony to prospect at 2 years of age (they don’t breed until they are 5 or 6 years old and can live up to 40 or 50 years)
None of this would have been possible without the rat eradication work so we salute those people from Wildlife Management International and RSPB staff and volunteers who toiled away at this task 12 years ago.
Good luck to those on the Isles of Scilly currently undertaking a rat eradication project on the islands of St Agnes and Gugh
Lisa digging in box #1
First one complete - hopefully we don't find a rabbit in there next time we check it!
A Manx sheawater fledgling on Ramsey - before the eradication project eggs and chicks stood little chance against rats