Manx sheawaters are arguably the RSPB's biggest success story on Ramsey. When we took over the island in 1992 it was plagued with introduced brown rats, a disaster for any burrowing nesting seabird which has evolved over millions of years to nest underground on offshore islands free of such predators.
In 1999/2000 the RSPB together with Wildlife Management International from NZ manged to eradicate the rats and the results have been extraordinary. In 1998 the population stood at just 850 pairs with productivity virtually zero. At the last full census in 2012 that figure had lept to 3,800 pairs. Our next full census is in 2016 and it will be interesting to see if the population has continued to rise over the past 4 years.
Today I was out surveying a small study plot to find out which burrows were occupied before spending a week in July attaching data loggers to birds in an on-going long term study on these remarkable birds migration patterns (they go to Argentina for the winter!). To do this we play a short burst of a recording of a male/female duetting pair and listen for a response. This is the only way to accurately survey a species that spends most of its life either at sea or underground! At this time of year birds are incubating eggs so you have the best chance of getting a response as at least one of the pair should be home by day.
I took this short video which hopefully illustrates the point and gives a glimpse into the underground world of the Manx shearwater. After a short burst of the MP3 recording the real thing calls back. This bird is a male (higher pitched than females)
As you will see I am accompanied by my trusty companion Dewi, our sheepdog! When he is off duty from sheep work he accompanies me on most tasks. He loves shearwater surveys as he can sniff them out long before I get to the burrow! He usually lies down outside a burrow to tell me if it is occupied or not. He is very well trained in this respect and its not unusual for dogs to be used to for seabird surveys. See this link for a story from Birdlife International - these are highly trained dogs however and ordinarily I wouldn't advocate taking a dog to a seabird island!
Signs were good today. 19 of my 21 study burrows were definitely occupied which means birds carrying data loggers from last year all seem to be present and correct. Fingers crossed our 2016 full survey sees the population go from strength to strength
To see these remarkable birds for yourself an overnight stay at a colony is required. Our friends and neighbours at the Wildlife Trust of South and West Wales manage both Skomer and Skokholm islands. You can book through the Trust to stay on either island - see here for details
This is what was making all the noise!