[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: breeding, numbers, nesting, and flight
> 2)Feathers evolved as a breeding aid-partially for display and
> partially to incubate broods. Thus they didn't have to directly
> evolve for flight, but are awful handy as an incubator and heat
> retainer for something that hasn't grown it's feathers yet. The
> barbels are great for retaining heat.
The problem with this is that feathers are designed to keep the
feathered animals body heat trapped in, so contrary to HELPING
incubation, they actually hinder. (Some?) birds develop a bare spot
of skin with increased vascularzation called a brood patch (with the help
of the hormones progesterone and prolactin, if you care) to allow body
heat to escape and incubate the eggs.