Subject: Color in birds
Date: Mar 5 16:18:54 2003
From: Lynn Schulz - linusq at worldnet.att.net


Does the book "Birds of Tropical America" help Bob Sundstrom when he leads
trips to Antarctica?
Envious of all of you... ;-)
Carol Schulz
DesMoines, WA
linusq at att.net
----- Original Message -----
From: "Robert Sundstrom" <ixoreus at scattercreek.com>
To: <floriferous at msn.com>; "tweeters" <tweeters at u.washington.edu>
Sent: Wednesday, March 05, 2003 11:13 AM
Subject: Re: Color in birds


> The popular conception that most birds in the tropics tend toward the
> amazingly colorful is very ably discussed by Steve Hilty in his book
"Birds
> of Tropical America" (1994, Chapters Pub. Co.) in a chapter titled "Who is
> the Fairest? Colorfulness in Tropical and Temperate Birds." There is a
lot
> more in this chapter than can be summarized in this email, but two points
> are especially worth mentioning.
> First, the proportion of colorful birds is actually about the same in the
> tropics and the temperate zone, but the birds one associates with the
> tropics (and more likely sees well) are the glamour birds: colorful
toucans,
> parrots, tanagers, trogons instead of the hundreds of species of
earth-toned
> antbirds and ovenbirds (not to mention 360 plus species of flycatchers).
> Second, "to see colorful birds, you have to look up into the brightly lit
> branches of the rainforest canopy. There, strong sunlight fashions a
> high-contrast world of lights and darks that simultaneously dazzle and
> confuse. Bright birds move easily in a world where color catches the sun
> one moment and then fades in a shadow the next. Color is riotous and
often
> flaunted with impunity in the rainforest canopy. It may also be adaptive.
> Concealing color does not have to be dull and drab . . . anyone who has
> squinted into a sunlit rainforest canopy in search of a trogon or jacamar
> will appreciate how bright colors can disrupt a bird's shape (p.
132-133)."
> This is only a piece of the complex adaptive puzzle discussed in the
> chapter, and doesn't even raise the key point that many of the colorful
> birds of the tropics rely heavily on fruit. This book and Kricher's "A
> Neotropical Companion" go a long way to helping make sense of birding in
the
> Neotropics for those of us with a temperate zone birding frame of mind; I
> get great mileage out of them when leading a tour in Trinidad, Belize,
etc.
>
> Bob Sundstrom
> ixoreus at scattercreek.com
> Tenino, WA
>
> ----- Original Message -----
> From: "Rob Sandelin" <floriferous at msn.com>
> To: <tweeters at u.washington.edu>
> Sent: Wednesday, March 05, 2003 8:28 AM
> Subject: Color in birds
>
>
> > I must have missed this lesson in my ornithology class.
> >
> > Why is it that there are so many species of highly colored birds
resident
> in
> > the tropics, and so few in our area? Once I got over the shock of some
of
> > the colors I saw in Costa Rica I got to wondering. Territory seems to be
> set
> > by vocalization, not necessarily color. Why is color a selection force?
> Or
> > is it? Do brighter males get better territories, or more mates? Do
females
> > choose males for brightness because that indicates fitness?
> >
> > While in Costa Rica I watched some kind of bird eating hawk nail a
Scarlet
> > tanager in midair. It seems in that case, being so contrasting against
the
> > jungle made for easy pickings. This would seem to make one think bright
> > color would be a selective disadvantage.
> >
> > And to whom do I complain to about getting more color in the northern
> > birds? After two weeks of wild electric blue Honeycreepers, and Toucans,
> the
> > chickadees and juncos and song sparrows are just not satisfactory. Ahhh,
A
> > stellars jay did liven up my feeder this morning so I feel a little bit
> > better......but still, how come northern birds are sooooo uncolorful
> > relative to the tropics?
> >
> > Rob Sandelin
> > Sky Valley Environments <http://www.nonprofitpages.com/nica/SVE.htm>
> > Field skills training for student naturalists
> > Floriferous at msn.com
> >
> >
> > ---
> > Outgoing mail is certified Virus Free.
> > Checked by AVG anti-virus system (http://www.grisoft.com).
> > Version: 6.0.332 / Virus Database: 186 - Release Date: 3/6/02
>