Saturday, 21 May 2011

Eiders again - the toilet duck is hatching.

The toilet ducks chicks are hatching today.

The toilet duck on nest.

The engine room duck.

Things are happening with the eiders on the island. A few weeks ago it was mayhem on the loch as all the pairing up went on. The females then headed out onto the island to find a site for their nest and these are literally all over the island. Some hide away in undisturbed parts of the island where people seldom go while others nest right in amongst us. There is one duck that nest right out side the toilets of the visitor centre and so has thousands of people cue up virtually next to her, she now has the unfortunate name of the "toilet duck". And then there is the "engine room duck" and the "Internet cafe duck" who nests on the concrete pad outside the cottages where we can get a good mobile phone signal. It might be that these ducks next in these places because the presence of humans keep their main threat, the gulls away. But some females nest right in the middle of the gull colony which seems very odd but gulls will even eat each others eggs in a colony so maybe they are spending so much time guarding their own eggs that they won't worry about predating an eiders.
These eiders have an incredibly strong instinct to brood and it takes a lot out of them. The eggs take 26 days to hatch and during this time the females may only leave the nest to get water. When they do this they cover their eggs with down and vegetation to hide them and head for the nearest pool. So by the end of incubation the females can have lost up to 40 % of their body weight, sometimes being in such poor condition that they lose their waterproofing of their feathers. It has been known for an eider sitting on sterile eggs to have died on the nest rather than leave the eggs. All through the 26 days gulls and people are the greatest problem. Gulls will hassle and gang up on a female that looks flighty and take the eggs if she moves. People are a problem if they step off the path and frighten a female off her nest, then the gulls come straight in and we have lost a couple of clutches this way this season.
And now the clutches are starting to hatch. As soon as the ducklings appear the female has to head off to the nearest water for her and the ducklings to feed, protecting the ducklings from gulls as she goes. In this she gets help from other females either non or failed breeders that are often related. Over the next couple of weeks the mortality is high for the chicks but enough will survive to come back in future years.
The Isle of May is a really important place for eiders. It is one of the largest concentrations of breeding eiders in the UK holding about 5% of the Scottish and 3% of the UK breeding population. The numbers rose rapidly during the 1980 and 90's but seemed to have stabilised at roughly about 1000 pairs. Islands are important because on the mainland they are often disturbed on the nest by walkers and dogs. In one area of the East coast the breeding eiders have almost disappeared after the opening of a coastal long distance path.
And today the toilet ducks chicks started hatching, a special treat for visitor on the boat. But once the chicks have hatched from all of the nests around the cottages I will miss the early morning wake up call that we get from the females talking to each other with their "muck, muck, muck, muck, muck" call. Until next year.

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