Tuesday 8th December comments: As we mentioned in yesterdays blog post, some seabirds remain all year round in Isle of May waters but interestingly Eider duck numbers have increased and displaying has started, but why and is this early?
The Isle of May is one of the most important Eider colonies in the country with the last census revealing 1,200 nesting females (population graph shown above). Eiders are the UK’s heaviest duck and fast flyer at level flight. During the winter months vast number congregate in places like the Firth of Forth as the breeding season starts from April on remote predator free islands like the Isle of May (although very small numbers can be found nesting on the mainland). Eiders are diving ducks which feed on a variety of prey but especially on crustaceans and molluscs.
At this time of year birds are in fine plumage, the dapper drakes are looking splendid and the females are incredibly subtle but beautiful all at the same (they are more than just a brown duck, just check out the photos above). If you are lucky to see these birds (they winter around our coastal towns and harbours) then just keep watching and listening because the flock will be very vocal, especially the males.
During the winter months drakes will start displaying, which involves exaggerated head movements complete with a low cooing call which was described by BBC Radio Four as like a panto dame or Frankie Howerd (a great description), Check out the sound on this BBC Springwatch film about Eider ducks on the Isle of May: https://twitter.com/bbcspringwatch/status/1007645154239447040?lang=en
Displaying also involves rearing up out of the water and flapping wings. Eiders like many northern ducks start displaying and pair bonding during the winter as the breeding season is so short in the far north, that it saves time. As the birds arrive back at nesting areas, the displaying and pair bonding has all been complete and the female can get on with the business in hand of raising a family. So there you have it, it’s not early to see and hear displaying Eiders so the next time you are at the coast, check it out, you’ll not be disappointed.