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Re: More evidence of dinosaur colors

Augusto Haro <augustoharo@gmail.com> wrote:

> Sorry Tim, but what makes your wagtail hypothesis more
> testable, or more or less wacky, now than in 2007?

Apparently in birds that engage in 'flush pursuits' of small prey it's not just 
the behavior (wing-flashing and tail-wagging) that's important, but coloration 
as well (Jablonski, 1999; Behavioral Ecology 10: 7-14).  Color contrast in the 
plumage plays a role - specifically the areas of the wing and tail that are 
flaunted during this behavior...

>From Jablonski (1999):

"During foraging, typical flush-pursuers such as _Myioborus_ species (e.g., 
Moynihan, 1962, Ridgley and Tudor, 1989), _Setophaga ruticilla_ (Robinson and 
Holmes, 1982), and most of the genus _Rhipidura_ (e.g., Holmes and Recher, 
1986, Recher et al., 1985) forage with constantly half-spread wings and broadly 
spread and half-raised tail exposing distinct bright patches in the tail and 
wings (e.g., _M. pictus_, _S. ruticilla_) or rump (e.g., _R. rufifrons_). 
[snip] Because contrast is important in eliciting insect escape responses 
(e.g., Holmqvist and Srinivasan, 1991), the evolution of the flush-pursue 
foraging mode has been suggested to promote selection for bright plumage in the 
areas exposed during wing and tail spreading (e.g., Ficken and Ficken, 1962; 
Gander, 1931; Hailman, 1960; Jabloski, 1993, 1994, 1996; Remsen and Robinson, 
1990; Root, 1967)."



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