Last Friday I gave you this sound and skull combination to have a go at identifying:
As many of you worked out, the skull and call belong to quite different species that share a love of the seaside.
The call belongs to the somewhat enigmatic Common Eider Somateria mollissima (Linnaeus, 1758) as identified by mark b, Chris, Melanie, Henry McGhie, Anne Åslaug Holder and stuart petch.

A male Somateria mollissima (Common Eider) at the London Wetland Centre, Barnes, UK. By Diliff, 2013
These large marine ducks are at home on the water, where they feed on molluscs and crustaceans. They are probably best known for their super-soft downy breast feathers, that the females use to line their nests and humans use to fill their pillows.
The skull belongs to a Razorbill Alca torda Linnaeus, 1758, as identified by Ric Morris, mark b, Chris, Melanie, Henry McGhie, Anne Åslaug Holder and stuart petch.
These birds are great divers, using their wings to ‘fly’ underwater. They feed on small fish and other slippery critters, caught using that characteristic bill.
Congratulations to everyone who managed to work out what the two species were – there’ll be a final mystery sound from the British Library Wildlife Sound Archive to identify next week, courtesy of curator Cheryl Tipp!
Wonderful capture !