Twycross Zoo's Penguins. Freaks of nature or something sinister?

In an unusual turn, 3 of the penguins at Twycross Zoo have mutated their coats to match the clothing of some of the visitors to the zoo.

Could this be related to the missing llama? Should it have been a lemur that disappeared?

Edit: No harm came to any birds in the making of this picture for the 32nd March 2009.

Edit: Realising that the chance of a polarbear (thats me! - site logo) actually meeting a penguin, let alone the ~10 in this picture is very unlikely, I would like to remind you that the photograph was taken in a zoo.