Re: More evidence of dinosaur colors

[Dann Pigdon <dannj@alphalink.com.au>]

On Mon, Feb 8th, 2010 at 10:48 AM, Ronald Orenstein <ron.orenstein@rogers.com> 
wrote:

> Yes -- I spent two years studying Australian birds for my doctoral
> thesis in the seventies -- but it is not a wagtail (and, further, I
> am not sure that it uses flushing behaviour the way, say, the Rufous
> Fantail clearly does).

When Willy wagtails flush out prey they swoop down suddenly on a patch of 
grass, coming to a 
sudden halt just before hitting the ground by flaring the wings and tail.

It seems to be the rush of air from the sudden stall that flushes out prey, 
rather than a visual 
signal. Hence why the underside of their wings aren't brightly coloured.

It has also been suggested that their characteristic tail-wagging is mainly a 
flushing mechanism:
http://www.publish.csiro.au/?act=view_file&file_id=MU9930284.pdf

Most of the time though, willy wagtails tend to actively pursue prey in the 
air. Their 
manouverability gives them great confidence in attacking much larger birds that 
stray near their 
nest. Most larger birds won't even bother to retaliate, and simply try to 
ignore the little bird - 
although that's easier said than done. They're persistant little buggars.

-- 
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Dann Pigdon
GIS Specialist                         Australian Dinosaurs
Melbourne, Australia               http://home.alphalink.com.au/~dannj
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