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Re: Ultrasonic alarm call for Richardson's ground squirrel

Subject: Re: Ultrasonic alarm call for Richardson's ground squirrel
From: "Rich Peet" <>
Date: Mon, 09 Aug 2004 14:42:14 -0000
Thanks Jim and Greg for the post.
It is bad news for me though.  I was planning on setting up for the 
Richardson's that I visit twice a year with recordings at 24/96. But 
from playing more with bats I seem to be limited to about 41,000 
cycles with my equipment.  I will still give it a go in the spring as 
you recall the people alarm calls I recorded of this guy were audible 
although narrow and short.

It is good to note that there is very little background noise up at 
40,000 so a parabolic really is not needed for recording bats. The 
lowest echolocation call I have captured to date was down at 16,000 
which I just accidentally captured while recording at 44.1.

ps, this is a big gopher.

--- In  "Jim Morgan" <> 
> The following message has been posted by Jim Morgan for Greg Clark, 
a Nature Recordists member, that is having temporary posting 
> In the 29 July 2004 issue of "Nature" there is an article 
concerning an 
> ultrasonic alarm call for Richardson's ground squirrel 
> richardsonii) (The authors refer to Canada in the article) . The 
alarm call 
> frequency is very narrow, close to 50khz, and short, only 238 ms. 
> authors comment "To our knowledge, ultrasonic alarm calls have not 
> previously been detected in any animal group, despite their twin 
> of being highly directional and inaudible to key predators." The 
> used playback and a pure tone at the dominant call frequency (along 
> other control tones) to investigate the behavior of the squirrels. 
The pure 
> tone elicited "vigilant" behavior similar to the native call.
> I have two species of ground-dwelling squirrel that live in my 
backyard in 
> Arizona and I have a means of down-sampling the high frequencies so 
that I 
> can detect them. Perhaps I will hear a short click when the 
squirrels see 
> me. Those of us who have the means to detect ultrasonic signals, 
and are 
> around squirrels (especially ground squirrels) probably should have 
> listen for these frequencies in case they are found in other 
> I don't have a transducer that would transmit ultrasonic tones, but 
> might be another way to see if the squirrels take notice. I imagine 
> dogs in the neighborhood would be interested.
> Greg Clark
> [Non-text portions of this message have been removed]


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