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Re: pressure build-up ring

Subject: Re: pressure build-up ring
From: "werainey" werainey
Date: Mon Oct 20, 2008 10:17 pm ((PDT))
Typical calls from the Hawaiian hoary bat have their minimum frequency high=
er than  on
the continent,so even when cruising in open air, they don't often get below=
 20 KHz. In
contrast, the no obstacles open air call Sequence in  Yosemite or Alberta ,=
 could be 16
KHz or somewhat below. Haory bat social calls get down to 8-10 KHz but are =
very
different that mastiff calls.

In several batches of recordings from Kauai, open air calls are largely in =
the 20-30 KHz
range, but when the bats are interacting with prey or other bats, the basel=
ine rises, so the
frequency range then  is often more like 30-65 KHz.

If you don't have a starting point on Kauai, they hunt over the parking lot=
 lights at Kalawai
Park in Kalaheo and likely in similar situations elsewhere. I'm told you ca=
n see them over
the bay at Salt Pond Park. A group  of bats appeared shortly after dusk and=
 hunted an
insect swarm at human head level  in a distinctive (there is only one) stra=
ight stretch of the
Waimea Cyn road that is hemmed in by tall Eucalyptus. I can find the coordi=
nates if you
wish.

Bill R.
> Can someone say what this is, how=C2=A0 it is applied, and how much hf re=
sponse
enhancement can be expected? I'm going out hunting=C2=A0for the Hawaiian Ba=
t (a sub-
species of Hoary Bat, whose echolocation call is said to be 15-30 Khz). The=
 MKH 20's freq
response only goes to 20Khz.
>
> Thanks,
> David
>






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