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Re: pterosaurs, bats, flying theropods (fwd)
> > One may argue with and ridicule pet hypotheses based upon extrapolating
> > extant behavior back to the Cretaceous. However, one should not
> > argue that an extant, fully observable phenomenon, is not generally
> > true by arguing it's only a generality!
> One should appreciate both the way things generally are and every single
> exception. Otherwise wrong explanations for both are easy to find.
> What about another idea: birds were already there in the daytime, and, in
> order to _avoid_ competition, most microbats stayed nocturnal. (Assuming
> nocturnal ancestors is of course not so easy to test, but nocturnal
> are not exactly something rare, maybe this condition is the plesiomorphy
> placentals.) The whole niche partitioning and competitive exclusion thing.
Check out: http://www.cmnh.org/dinoarch/1996Aug/msg00050.html
Where raptors are absent, microbats forage diurnally. If they didn't have
to deal with predation they may well outcompete birds in the day time! But,
this _is_ a form of competition: birds can cope with the predation regime,
Who knows what was going on in the Mesozoic. But this phenomenon in
extant species could be an important clue for birds