At 11:55 AM 2/6/00 +0000, Julian and Jackie wrote:
>Rebecca Allbritton <[EMAIL PROTECTED]> wrote
>>
>>They had a special device with a microphone hooked up to it to make the
>>sounds that the rats were making audible to human ears, because the rats'
>>"laughing" squeaks were too high for humans to hear. That makes me think
>>maybe other rodents can hear & make noises higher than we can hear (I know
>>dogs can), and maybe respond to them like your gerbils were. Maybe yours
>>hear mice or rats or squirrels or aliens outside squeaking. =)
>
>There has been some study of ultrasonic communication in gerbils. They
>definitely talk more often than we think! They also make ultrasonic
>"calls" when they make sudden movements but these are probably due to
>compression of the chest caused by the movement rather than an attempt
>at communication.
>
>DEVELOPMENTAL CHANGES IN SEVERAL PARAMETERS OF ULTRASONIC CALLING BY
>YOUNG MONGOLIAN GERBILS (MERIONES UNGUICULATUS).: Broom, D.M., Elwood,
>R.W., Lakin, J., Willy, S.J., 1977, Journal of Zoology London, 183,
>281-90
I wonder why it is that pups and younger gerbils are reported to squeak
more often in the human range of hearing (fairly low) than older gerbils
are? I've been introducing a 7 week old male pup to a 4 month old male
(split cage), and the little male has been squeaking when they're close. I
wonder if it's their equivalent of a low growl? Or if it's terror or fear,
why isn't it higher, & out of human range? Do you suppose the older guy is
also squeaking & I can't hear it? Any opinions, anyone?
Do you have that article to hand, Julian, and if so, what changes did they
notice as the gerbils grew?
Rebecca...
