I ddarllen hwn yn y Gymraeg, cliciwch yma os gwelwch yn dda
RSPB Ramsey Island, surrounded by dramatic off-shore cliffs and crashing waves, is one of the best places to spot some of our most fascinating seabirds and wildlife, from choughs nesting on the cliffs, to grey seals popping their heads up along the shores. Of late, the island has become renowned for the ever-increasing breeding Manx shearwater population, but this wasn’t always the case for these nocturnal marvels...
Image: Dave Boyle. An RSPB Ramsey Island Manx shearwater.
Way back in the mid 1800’s a fierce gale battered the coast of Ramsey, driving a cargo ship running the gauntlet of Ramsey Sound to a premature end on the island’s jagged rocks. This event was to shape the burrowing seabird populations of RSPB Ramsey Island for the next 150 years as brown rats swarmed ashore and soon decimated the once thriving puffin, storm petrel and Manx shearwater populations.
However in 2000, an ambitious rat eradication project was carried out between RSPB Cymru and Wildlife Management International from New Zealand. This paved the way for a dramatic recovery for some species and the welcome return of others.
Image: Greg Morgan. A Manx shearwater chick being weighed by RSPB Ramsey Island staff.
Storm petrels returned to breed in 2008 and now number 12 pairs and whilst puffins are keeping RSPB Ramsey Island staff waiting, it is the Manx shearwater that is the star of the show. This species managed to hang on during the ‘rat years’ thanks to overspill from the huge populations on the nearby Skomer and Skokholm islands. In 1998 the population was estimated at 850 pairs but by 2016, now free from the pressure of an alien invader, the population had risen to 4,796 pairs.
Providing a safe home in which to nest is only half the battle, though, as Manx shearwaters spend over half their life at sea, only returning to land to breed. They feed in waters around the Irish Sea and Celtic Deep and then migrate to the coast of Argentina for the winter.
Image: Greg Morgan. The nestboxes that RSPB Ramsey Island staff built.
To ensure we know as much as possible about their movements, RSPB Ramsey Island staff have been installing nest boxes to provide them with an easily accessible population to deploy geolocators on. These are miniaturised tracking devices that record sunrise and sunset. Then, by referencing an internal clock, the geolocator can provide an estimate of latitude and longitude anywhere on the planet. These devices are small enough to fit on a plastic ring and stay on the birds all year round. This enables us to ‘spy’ on the birds when they are on the other side of the world and hopefully spot any issues that arise at an early stage. This also
Over the past couple of seasons, we have built and dug in nearly 100 nest boxes on RSPB Ramsey Island. In 2016 the first two pairs bred successfully and in 2017 it looks like we have 7 pairs sitting on eggs currently. At this rate of increase RSPB Ramsey Island will soon have a thriving population which will provide the backbone for our tracking studies in Wales and further afield. This story is surely one to keep an eye on in the future.
For more information about RSPB Ramsey Island’s wonderful Manx shearwater, please contact ramsey.island@rspb.org.uk