RE: Third claw for climbing was Re: Pro(to)avis

[Tim Williams <twilliams_alpha@hotmail.com>]

Jerzy Dyczkowski wrote:

> Never heard of seriemas climbing trees.

This is what the _Handbook of the Birds of the World says of seriemas 
(Cariamidae):

"Nevertheless, aided by very sharp claws, especially the large claws of the 
innermost toes, they may cling to the bark and thus climb the trunks of 
small trees, or similarly jump through the branches of vegetation with the 
aid of occasional flaps of the wings."

Michael Habib wrote:

> However, there are other ways in which the long feathers present on the 
> hindlimbs could be involved with flight.  Here are a few I can think of, 
> I'm sure others can think of more:
>
> 1) The limbs may have been held subhorizontal, but still held close enough 
> to a horizontal plane to generate lift.

In the earlier stages of the evolution of avian flight, the hindwings, the 
forewings and the feathered tail may have worked together to maximize DRAG, 
rather than lift.  This means that the neither the fore- or hindwings needed 
to be held subhorizontally during aerial locomotion.

> (The problem with these ideas is that the increased drag would make it 
> harder to stay in the air).

Yes, but this same drag would slow the animal's descent (i.e., reduce the 
ker-splat! factor when the animal hit the ground).

Cheers

Tim