Re: Pterosaurs and birds, was Re: birds and pterosaurs

[jrc <jrccea@bellsouth.net>]

Many birds tend to lose body weight in direct proportion to the percentage 
of wing area lost during the moult so that the wingloading remains 
relatively constant during the moult.  This helps to maintain flight 
capability, albeit at somewhat reduced efficiency.
JimC

> I assume it is possible that feathers
> of Argentavis grew faster, or Argentavis could somehow
> find food with lowered ability to fly.
>
> Still, moult and growth of feathers is a constraint
> for modern birds. Feathers are keratin (protein) and
> plumage is a significant part of body weight.
>
> Jerzy Dyczkowski