Regular readers of this blog will know the chequered history that burrow nesting seabirds have had with Ramsey / Ynys Dewi over the years. Brown rats arrived in the 1800’s through shipwrecks and decimated the puffin and Manx shearwater breeding populations through the 1900’s.
By the time the RSPB bought the island in 1992 puffins had long been extinct as a breeding species and the shearwaters were reduced to around 500 hapless pairs who clung on but rarely managed to fledge any young.
Fledglings Manx shearwaters are now a common site on the island but pre rat eradication they were easy prey for this invasive non native predator (photo: G Morgan)
The eradication project that took place in 1999/2000 with Wildlife Management International from NZ has been well documented. At the time Ramsey was the largest UK island to be tackled and set the bar for UK eradication projects we have seen since on Lundy, Scilly and the Shiants
In the 22 years since the Ramsey project the response has been better than we could have hoped for. We carry out the arduous census every 5 years. It takes nearly 3 weeks, mainly on your hands and knees, playing the call of the male and female bird down a large number of burrows! From a pre eradication figure of 850 pairs in 1998 we have seen this increase markedly with each survey. Prior to this year the last count was 2016 and stood at 4,796 pairs. The 2022 figure now stands at (drum roll……)
6,225 pairs – a 30% increase!
Surveying nocturnal burrow nesting seabirds is never easy and, after counting all the suitable burrows on the island when the vegetation is low over winter (really!) we then play a recording of the male and female ‘duetting call’ to a percentage of all burrows (20-30% is our target, spread evenly across all survey sections, which gives a statistically reliable result) then insert into a fancy formula to arrive at our estimate.
Emily making 100% sure she can hear the response (or maybe she just nodded off!)
To go from 850 to over 6,000 pairs in just over 20 years is a fantastic achievement. It is testament to the hard work that went into the eradication project and champions the worthiness of future island restoration projects. Manx shearwaters have now overtaken common guillemots as the most numerous bird on the island – not that many people seen them as they are nocturnal on land!
We would like to thank the volunteers who helped Nia, Luke and I with this mammoth effort in 2022 – Sarah, Scarlett and Emily – you’ll be hearing shearwaters calling in your sleep for the rest of the year! (if you want to hear what a duetting Manx shearwater pair sound like click here)
At a time when the spectre of Avian Influenza is decimating our seabird colonies in parts of the UK it is nice to have something positive to report.
And despite rats being eradicated over 20 years ago the battle goes on to ensure the island remains that way. We practice strict biosecurity measures when transporting goods and supplies to the island and ask our visitors to do the same. So when our boatmen asks you to check your bags on the way over, you’re helping us keep Ramsey as the safe haven it has become for Manx shearwaters – long may the population keep increasing!
If you would like to see Manx shearwaters please contact Thousand Islands Expeditions who run evening boat trips during spring and summer to see birds gathering as they wait for darkness to make landfall. And to truly experience the sight and sounds of a colony an overnight stay on Skomer or Skokholm is a must. See our friends at the Wildlife Trust of South and West Wales for more details
Manx shearwater in flight over a glassy sea (photo: G Morgan)