[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]


On Fri, 2 Aug 1996, John Bois wrote:

>But they are almost completely outcompeted in the day time by 
>alula-bearing birds.  Any enhancement of aerial agility in a flying 
>animal must have a telling selective edge.  Although this is 
>self-evident, I also wonder whether other things such as increased 
>heaviness due to having to carry offspring within, or fragility of bat's 
>wings might also affect their day/night distribution?

Wouldn't the day/night distribution make more sense if bats evolved from
nocturnal ancestors?  And in just what arena where the birds and bats
competing?  Just because both are fliers does not mean they occupy the same
niche ("flying" is rather too broad a category to be considered a niche).
About the only direct competition would be between insectivores.  Even
there, bats are by no means clumsy in the air.    I think it is flawed logic
to simply state that because birds are diurnal and bats nocturnal, birds
out-competed bats and drove them to becoming nocturnal.

So, what do we know about bat evolution?  I can be e-mailed directly, so we
don't start up a non-dinosaurian discussion.

Derek Smith