Tuesday 4 June 2013

Talking Eiders




 I don't want to appear eider obsessed but this is another posting on eiders because eider things are happening. The eiders were slow to get started at the beginning of the season. They seemed to be hanging around the island, going through all the courtship stuff with the males but not getting down to the nesting business. And then suddenly there were nesting eiders all over the place, they all seemed to start at the same time.
Of course means that they are hatching at the same time as well. So we have ducks with ducklings all over the island. Its takes longer than normal to walk anyway because there are so many groups slowly making their way down to the sea or the loch.
But what I find interesting is that female eiders work as a team . Because nesting in groups they have evolved a cooperative behaviour where sisters and daughters that are non-breeders help out mothers with clutches. We can often tell if a female eiders eggs are about to hatch because another female will come and sit by her for a day or so beforehand. Once the eggs are hatched the team of females guide and guard the ducklings as they are lead from the nest. The gulls are the main enemy but several females can put up a good defence. The females will then lead the ducklings not just down to the sea but off across the 6 miles of water to the Fife Coast where the feeding is better and there are fewer gulls. Perhaps only 1 or 2 of the clutches of ducklings are raised to maturity on the island.
But how do the sisters and daughters know that the eggs are hatching ? Well, eiders do a lot of communicating, those that nest either side of the Fluke Street chat to each other across the cottages every morning (honest they really do) and it would be great to understand what they are saying.

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