Subject: [Tweeters] Evidence found that colorful ventral wings help colonizing birds avoid collisions
Date: Wed Jul 6 18:19:48 PDT 2022
From: Dennis Paulson - dennispaulson at comcast.net

Thanks for the link, Dan. I'll have to see if I can find a copy of the paper, as they didn't convince me. Of the birds in their lovely wing photos, jacanas and magpies aren't colonial, and Cattle Egrets are, so they didn't exactly choose the best species to illustrate their point.

My hypothesis is that birds that feed and flock together and benefit from being able to see each other at a distance and be conspicuous against just about any background color are much more likely to be white or black or-;as in the Am. White Pelican-;black and white. Many, many species fit this hypothesis, don't have any more contrasting ventral wing coloration than the Cattle Egret, and often occur in dense colonies.

I would say that Wattled Jacanas have yellow flight feathers as part of their display and keeping track of one another, not to prevent midair collisions. The same may be true for magpies.

But trying to understand bird coloration is always an interesting exercise!

Dennis Paulson
Seattle


> On Jul 6, 2022, at 7:01 AM, Dan Reiff <dan.owl.reiff at gmail.com> wrote:

>

>

> https://phys.org/news/2022-07-evidence-ventral-wings-colonizing-birds.html

>

>

> Sent from my iPhone

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