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Re: Evidence for bat predation on birds



Googling around on stuff like "chiroptera, altitude" gleans 3000m foraging for 
t. braziliensis... I was mainly wondering about maximum observed reproductive 
altitude. 

As usual the most interesting stuff is accidental-- e.g., it seems species 
richness in birds and bats "declines smoothly" w/ increasing altitude (in the 
Andes) whereas species richness in local mice does not. Further, the mouse 
species are more 'discretely zonated' than the volants. Encouraging and 
unsurprising to a functionalist like myself, who assumes that the gradual 
change in flight medium density has shaped the bird/bat species profile... in 
all the ways you might theoretically expect. I hasten to add that as near as I 
can tell, the authors listed below don't necessarily share my locomotively 
based assumption. Hard to tell until I get the whole article.

This is a little surprising if you just paste it into a black/white cartoon 
world-- "Highland bat species occupy broader elevational ranges than lowland bat
species, but for both birds and mice, species at intermediate elevations
had the broadest amplitudes."



Ref-- Contrasting Patterns of Elevational Zonation for Birds and
Mammals in the Andes of Southeastern Peru-- Bruce D. Patterson, Douglas F.
Stotz, Sergio Solari, John W. Fitzpatrick, Victor Pacheco. Journal of 
Biogeography,
Vol. 25, No. 3 (May, 1998), pp. 593-607



As to calculation, that would be interesting. However, I know if I tried it, I 
would hurt my brain, so be careful.

Don

----- Original Message ----
From: Michael Habib <mhabib5@jhmi.edu>
To: d_ohmes@yahoo.com
Cc: dinosaur@usc.edu
Sent: Thursday, May 31, 2007 5:46:09 PM
Subject: Re: Evidence for bat predation on birds


> To change the subject slightly, and take advantage of list expertise, 
> what is max altitude for bats (flight, habitat)?
>
> Don

Good question; do you mean maximum observed altitude or maximum 
expected based on planform and mass?

The maximum observed altitude would, I think, be that recorded for 
molossid bats during long distance foraging.  I don't know what the 
figure is off the top of my head, but I can find it easily enough 
(perhaps someone onlist has it handy).  Maximum altitude expected from 
morphology and flight dynamic is going to be trickier... I'm not sure 
what that would be for bats without doing some calculations.

I'll look up that molossid tracking work and get the altitude report as 
soon as I have a chance.

Cheers,

--Mike H.