more useless facts 2

[Parko]

Hix, i am not arguing that parrots can't see colour, i don't know whether they can or can't. I am arguing against the statement that a parrot must be able to see blue because it has blue plumage. I have simply shown that there are other reasons for a parrot to have blue, for example crimson rosella's bright red and blue or Rainbow lorrikeets even, both these birds are brightly coloured yet almost dissapear when sitting motionless amongst eucalyptus foliage. Blue and red can indeed be a great camouflage. If you start to mention rods and cones then that is an argument i wont get into because i know nothing of the matter so would presume you may be correct. Simply saying an animals colour does not often have any relation to what colours they see. Why does a gouldian finch have such bright colours if it can't see those colours?
Did i at least put a tiny little dent in your argument if not a tear? :?

 

[Hickson]

Did i at least put a tiny little dent in your argument if not a tear?

Nope.

Based on the information you have, you come to some valid conclusions. And there may well be some birds that are blue for camouflage reasons. The example I used (Hyacinth Macaw) would be hard to see in a darkened rainforest - but I'm not suggesting their plumage is hyacinth specifically for camouflage purposes. I'm merely suggesting that it would be an advantage to have the plumage that colour. A side-benefit, if you like.

My original argument was that many birds other than owls can see blue. I used parrots as they are multicoloured, and most people have seen a blue macaw of one species or another. And my argument was that, with all the multicoloured birds around, it would be pretty silly to have those colours if they couldn't see them. Especially when you consider dimorphic species where the brightest coloured males tend to attract more females eg. Birds of Paradise.

When it comes to camouflage in birds though, they tend to go for drab browns and greys. For instance, the Superb Blue Wren (and several other species of Fairy Wren). Females are a brown colour which is excellent camoflage in dense shrubs. Males are the same for most of the year but during breeding season they turn bright blue in order to attract a mate. For a small bird like that, blue is not advantageous as they are quite conspicuous to predators like hawks, currawongs, Kookaburras etc.

For larger birds like the Macaws, they have less to worry about from predators so they can stay gaudy all year long.



Hix

 

[Parko]

After doing a bit of googling it would appear you are correct Hix and the useless facts statement that only owls can see blue is very very wrong, indeed perhaps it is a type error and should read ''of all birds only owls CANNOT see the colour blue''. Indeed birds can not only see the colours that humans can see but they can also see 2 ultraviolet colours which we cant, while the cones in human eyes work with 3 colours, red, blue and green, birds work with 5. A bird of prey can see a mouses urine trail from high up in the sky glowing in ultra violet colours, thereby locating their prey so simply. It is thought that birds may be able to see magnetic fields also, therefore being able to see a simillar effect to the northern lights on any day in any place on the globe. It is an understatement to say that birds, except Owls, live in a very colourful world.
So indeed this threads ''Useless facts'' appear to be exactly that, useless
One good thing though is i learnt a few things about bird vision.

 

[krusty]

ok then you lern something new every day