One of my dogs barks at people of Afro-Caribbean and Asian descent (less so with Asians), which can be extremely embarrassing, as you can imagine. I put this down to the fact that dogs' eyes detect shade better than colour, and it was the darkness he recognises, and takes umbrage at.
Birds, however, have excellent colour vision, and aren't as able to differentiate shade. This is an evolutionary trait caused by the fact that birds, unlike mammals, have never had a prolonged period as nocturnal animals. Mammals tended to develop night-time habits to avoid predators; birds were able to fly away. This has led to the development of five different types of cone cells in the eye (those that detect colour, compared to mammals three. They have the blue, green, and red receptors, but in addition possess one for violet (and in some cases ultra-violet), as well as a specialised cone cell to detect movement.
But even if it was a colour the swan was taking a dislike to, for example in the person's clothes (as opposed to skin colour), you would expect all swans to act similiarly. It could be that something has happened to this particular swan, and something about the people it attacks makes it behave aggressively.
I am sure we will never know the answer, with today's headline being tomorrow's fish and chip wrapper, and the only way to find out would be a controlled trial. It's not going to happen with a mute swan in a park, is it?
Interesting, though
-- Edited by David Walsh on Saturday 12th of April 2014 12:09:47 AM
I've heard this about dogs as well - but surely it can't be that they discriminate and, as you suggest, circumstances arise and people make news out of it!
Is anyone listening to Jeremy Vine on BBC Radio2 right now? Apparently a male Mute Swan is targeting ethnic minority students at Warwick University. I've never heard such rubbish. Have they never thought that it might just be by chance that the majority of students passing the Swan's territory just happen to be of ethnic minority . Cheers Rob
