Why are some birds so bonny?

[Deb London]

I apologise in advance for asking a wishy-washy girlie question. Not one for the "real men" of WAB.

I was weighing up the Goldfinches on my feeder today. Even the younger members of the clan had a beautiful and colourful pattern to the wing feathers. It's not just that they have bright colours. There is symmetry and form. And the adults of course are even more beautiful.

I then considered the Dunnock. Beautiful in its own way, but not as showy as a Goldfinch.

As aesthetically pleasing as some birds are to us, I reckon being so must have its disadvantages. Aren't females usually drab to conceal them on a nest? Wouldn't it be better if individuals blended with their surroundings when feeding? Those bright yellow feathers of Goldfinches must shout "EAT ME" to even the blindest of Sparrowhawks.

If it's all about attracting a mate, why do the juvenile Goldies have a pattern on the wings? And if it's just about getting noticed, why are they so beautifully patterned, and not splashes colour?

Surely birds can't appreciate the beauty of their own kind.

[loripo]

Do birds have similar colour vision to us? (that is a question - not arguing with your point)
I often wonder that about bugs - the instars often look far more colourful than the adults...

[Adam Cheeseman]

Originally Posted by loripo

Do birds have similar colour vision to us? (that is a question - not arguing with your point)
I often wonder that about bugs - the instars often look far more colourful than the adults...

It depends on the species. Some have been shown to have differing sight qualities to others.

Cheers,

Adam

[RoyW]

Originally Posted by Deb London

I apologise in advance for asking a wishy-washy girlie question. Not one for the "real men" of WAB.

I'd say that this is actually a good question, and one that will be very difficult for anyone to answer properly without putting in a lot of effort - so one to "separate the men from the boys"!

I'm going to leave it for someone else to answer, and will just say that there are lots of very different possible reasons for colours/patterns/etc to have evolved. In cases like the Goldfinch the sudden flash of colour on take off may even surprise predators (compare with many other animals, including many moths and other insects).

Originally Posted by Deb London

Surely birds can't appreciate the beauty of their own kind.

Why not? Sexual selection, based on visible characters is used by many animals. They may not see 'beauty' the way we do, but many colours and other plumage features seem to have no function other than attracting a mate (and most birds do see well in colour).

[Deb London]

Originally Posted by RoyW

Why not? Sexual selection, based on visible characters is used by many animals. They may not see 'beauty' the way we do, but many colours and other plumage features seem to have no function other than attracting a mate (and most birds do see well in colour).

I think I find it hard to believe because the pattern on the Goldfinch's wings seems to have been selected for symmetry. It almost looks designed. If the bird can appreciate that, I reckon that shows there is more to its thoughts than I had imagined.

I will continue to research the answer to the question. Interesting thought about the flash of colour being a surprise to predators.

[RoyW]

Originally Posted by Deb London

I think I find it hard to believe because the pattern on the Goldfinch's wings seems to have been selected for symmetry. It almost looks designed. If the bird can appreciate that, I reckon that shows there is more to its thought than I had imagined.

There is symmetry in the majority of organisms (certainly all birds - I can't think of any that don't show this). Rather than 'design', I think that this is perhaps just an illustration of the way genes are expressed (+ probably unconcious selection pressures, with symmetry being perceived as 'right' even if the animal isn't aware it is making this choice).

[davecatt]

This is just a personal theory and I don't know of any scientific evidence to back it up:

Is it possible that the species that have bright colourful plumage in both sexes share the brooding between the male and female,but others only have one partner sitting on the nest whilst the other (more brightly coloured partner) serves as a distraction for any potential predator?

Consider the King Fisher,one stays hidden in a hole sitting on the nest the other is outside hunting for food and keeping watch. The Goldfinch's wing pattern can blend in with the surroundings when it is immobile, but the sudden flash of colour when it takes flight draws attention to it. The male Robin not only has a bright red breast but is also very noisy and agressive whereas the female is dull coloured and sits quietly on the nest.

Dave

[hels]

It's a fascinating subject, one which I have been doing a lot of reading about lately.

There's a bit of interesting research on birds of paradise here Dancing Bird Shakes Its Groove Thing : Discovery News

And if you are interested in feathers generally, there's a fairly new book named feathers by Thor Hanson. Covers a lot of interesting stuff :-)

[solus]

Originally Posted by davecatt

The male Robin not only has a bright red breast but is also very noisy and agressive whereas the female is dull coloured and sits quietly on the nest.

Dave

Surely male and female Robins have exactly the same plumage!

[davecatt]

Originally Posted by solus

Surely male and female Robins have exactly the same plumage!

The Bright red is only visible when not sitting on the nest. I was under the impression that only the female Robin broods whilst the Male guards his territory and provides food. Perhaps I should have expressed myself better.