Being a West-Coaster fixing to move to the East Coast, I sense a bit of West Coast bias in the question. In the East, you have Cardinals, more of the colorful warbler species and we mustn't forget about bluebirds, whether East or West. That said, the number of colorful species in the south and into other more tropical countries far surpasses what we have here. I do know that some of the more colorful species in the tropics can still be very hard to find, because their color is actually a good camoflage in a brightly lit forest full of vibrant greens, yellows, reds and blues. Trying to find a Blue-crowned Mot-mot we could hear clearly proved difficult. Those gorgeous Keel-billed Toucans are noisy from afar, but as you get closer, they shut up, and you have to look closer. When you do see them, you are more likely to see silhouettes than a bright bird in a clearing. When they are in a sunny spot, one can note that their yellows and greens closely match brightly lit foliage of !
surrounding flora.
So my hypothesis would be that birds in tropical climes often posess brighter colors due to the brighter world they live in, as opposed to birds of more temperate, northerly climes that see less, more angled sunlight, which often posess more drab grayish and brownish patterns. I'll be spending 3 months or so in Belize next winter (still waiting on some of my funding sources), doing some banding for the Institute for Bird Populations' MoSI program, so I look forward to seeing if parts of my hypothesis can hold up. I can already see room for major holes to be blown in it, but hey! All science is generalities anyway! I just find this to be a fascinating question and subject.
Brett A. Wolfe gismybabe at yahoo.com Seattle, WA
JLRosso at aol.com wrote:I think that there is at least the potential of a book in this question.

I would further suggest that the majority of United States birds that are very colorful are migratory species, who spend their winter in the tropics. I think that if we made a subset of birds that are our resident birds that we could describe their colors as "muted." (I am trying to describe their colors in a non-pejorative way.)

My only stab at an answer at this intriguing question is to paraphrase one of David Snow's points in The Web of Adaptation (this is stretching back a fair ways so I may be inaccurate) that the food in the tropics is fairly plentiful and the birds were able to utilize their time for developing more and more complicated, fancy, and glittzy courtship patterns. This process also brought about more colorful feathers. Now of course as you mention, there are times when the male Scarlet Tanager could probably do without its bright colors, but in the competition to breed there is nothing like a little black against red.

Jim Rosso
Arlington, Va
jlrosso at aol.com
703-685-2426
http://birdcentral.net/


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