This is a nod to an oft quoted possible mistake of "Desert Island Discs" for the theme tune "By the Sleepy Lagoon" by Eric Coates contains bird noises. However, these birds are herring gulls — and many listeners have seen fit to point out with some indignity that herring gulls would not have been on a tropical island at all, so either the birds are wrong, or the "desert island" is simply a walk away from a bustling seaside town.