This last week we have had a very special visitor around the jetty area, rolling out the rosy carpet and giving people a warm welcome to the Isle of May: a Roseate Tern.
Roseate Terns are a rare breeding bird in Britain, with less than 100 pairs nesting the UK each year. The bulk of these are concentrated on the North-east coast of England but now and again, we get birds finding the Tern roost on the May. They can be told apart from the Arctic Terns at this time of year by the all dark bill with a slightly paler base. The bill is also slightly longer and thinner. The underparts are a dazzling white colour, a more brilliant white which really stands out. Adults often show a rosy tinge to the breast when breeding, hence the name! The black cap is slightly more extensive on the head. They also give a very distinctive ‘kuwick’ call, very different from the other Terns. The legs are slightly longer and paler and there’s a quick trick when it comes to Roseate Tern ID.
If the bird is ringed (and they often are) then it should be carrying a ring on each leg. One normal BTO metal ring which carries seven small digits and one special ‘Roseate ring’. This ring usually has just four digits which are larger and easier to read through a telescope. We have managed to read the ring of the bird that’s been here on the May and it was ringed as a chick on Rockabill Island off Dublin in the summer of 2012. It was first seen on 30th July and is still with us, associating with the Arctic Terns. With this bird probably prospecting for a breeding colony, there is hope it might be a potential future colonist.
Roseate Terns are also one of the only Terns that are kleptoparasitic. This means they will chase other birds and harass them until they drop their fish, stealing them for themselves. So they’re not just a pretty face. If you’re coming out to visit us, you might be lucky enough to catch a glimpse of this rare visitor.