Re: pressure build-up ring

["werainey" werainey]

David,
There are a batch of research papers on the Hawaiian hoary, though typically 
the illustrations 
of call structure are dismal. If your question is more general about how bat 
calls vary across 
species, habitats and activity, there's a good review  from a couple of years 
ago that I could 
send as a pdf to the  address on your web site. Bats are the second 
most speciose 
group of mammals and the fossil record suggests at least some  extant families 
separated 
long ago . There are quite profound, partly hard-wired differences among some 
in how they 
locate prey by ultrasound.
Bill
>
> Many thanks Bill, that is very enlightening--I have a new window on 
> the lives of these creatures. Can you refer me to a source of more on 
> their utterances?
> David
>