Re: ...bats by day, and bats, birds, by night.

[John Bois <jbois@umd5.umd.edu>]

On Tue, 30 Jul 2002, David Marjanovic wrote:

> > I think what we are seeing is a kind of niche partitioning:
> > birds are better competitors at some times, and bats at others.
> 
> This _is_ competitive exclusion: each has its niche and keeps the other out
> of evolving into that niche.

I thought it was agreed that competitive exclusion was defined as
complete exclusion of a nische, and that since neither bats nor birds are
excluded--they share habitat, prey, and they _overlap_ temporally--they
are not excluded.  You seem to want to eliminate the distinction between
niche partitioning and competitive exclusion.   I feel this is a useful
distinction because it shows that organisms competing for the same
resources can find ways to coexist.

> > If not, are
> > you really saying that juvenile frames are just as airworthy as adult
> > frames.
> 
> I am -- for those pterosaurs with more or less known ontogeny. Not for
> everything in general.

How does this affect the argument (if at all): flying
foxes take an inordinate amount of time to get their young airborne.  Here
are the data--how do they compare to any relevant bird?  Baby six months
gestation time, then 14 weeks before foraging (i.e., full flight
capability).  This is way off scale for any bird, right?  (The analagous
period being from laying to flying).