RE: Cost in Aquatic Birds

["Williams, Tim" <TiJaWi@agron.iastate.edu>]

David Marjanovic wrote:

> Other studies disagree to varying extents. Anyway, the toe claws are
> quite strongly curved, but the finger claws much more so -- I wouldn't 
> expect that in a climber --, and Archie's feet aren't good for perching.

A great many modern birds don't have feet specialized for perching,
particularly those that spend most of the time on the ground, but are
nevertheless capable of perching.  Certain galliforms come to mind - those
that I've recently seen referred to their own "order" Craciformes.  The
hallux is short or high on the foot, but nevertheless participates in
securing a grip on branches.

Ebel's swim-to-flight model has resurfaced again on the DML.  There are some
pretty loopy theories out there on the origin of avian flight, but this must
be one of the top contenders.  Like Thulborn's 1985 theory, it takes a very
literal (and littoral) view of _Archaeopteryx_'s habitat in shaping the
wing.



Tim 



------------------------------------------------------------ 

Timothy J. Williams 

USDA-ARS Researcher 
Agronomy Hall 
Iowa State University 
Ames IA 50014 

Phone: 515 294 9233 
Fax:   515 294 3163