This particular species of tree frog is so small that it's really hard
to distinguish size between one and another. I'm pretty sure that they
are both males but I had no way to check, since they mostly vocalize
at dusk or after dark when they're impossible to see without a night
scope, which I don't have.
BK
On May 5, 2011, at 10:40 AM, chrishails50 wrote:
> Bernie what a brilliant lesson - great in its simplicity. Two
> questions (I don't know this species - or frogs either for that
> matter)- could the tone difference be due (1) to sexual or size
> differences, or (2) maybe the guy in the pipe gets to project his
> higher frequencies better ? That aside the instantaneous change in
> call type shows just how closely they are are connected in
> behaviour. Thanks you, enjoyed this a lot
>
> Chris
> http://www.wildechoes.org
>
>
> --- In Bernie Krause <>
> wrote:
>>
>> Pacific tree frogs are about the size of the tip of your little
>> finger. Yet, tiny as they are, their voices have been measured at
>> 85dBA from 4.5m (15 ft.). Dominant individuals find resonant places
>> to
>> project their voices far and loudly.
>>
>> This spring, there are two around our small lap pool. The dominant
>> frog =EF=BF=BD as it has for the past several years =EF=BF=BD sets up sh=
op in a
>> 1 inch
>> outlet pipe at one end of the pool that it uses as a resonator. Its
>> competition has nothing but an open grass-like area about 3m (10 ft
>> away) from the main dude in which to vocalize. The open space
>> disperses its voice and it appears to be much lower in level. Rather
>> than chorusing and frequency niches, these two compete for temporal
>> niches; first one will vocalize (usually the dominant one with the
>> higher-pitched and more urgent-sounding voice), followed by a weaker
>> and lower frequency sounding second individual.
>>
>> What was not recognized before, is that they also mimic each other.
>> When the dominant voice changes, the sub-dominant individual follows.
>>
>> Here=EF=BF=BDs the link to a short clip made about 10 days ago showing b=
oth
>> the temporal niche exchange and mimickry. We=EF=BF=BDll be doing a paper=
on
>> this observation but wanted to share it with the group, first.
>>
>> Bernie Krause
>>
>> http://soundcloud.com/wildsanctuary/pactreefrogs0411/s-T8vci
>> Recorder: H4n (internal mics), 44.1/24
>> Date/Time: 27 Apr 2011, 2023 Hrs
>> Weather: clear, calm, 50% humidity, 68F/20C
>> Location: Glen Ellen, CA, approx. 122.5W/38.4N
>>
>>
>> Wild Sanctuary
>> POB 536
>> Glen Ellen, CA 95442
>> 707-996-6677
>> http://www.wildsanctuary.com
>>
>> Google Earth zooms: http://earth.wildsanctuary.com
>> SKYPE: biophony
>>
>>
>>
>>
>>
>>
>>
>
>
>
>
> ------------------------------------
>
> "While a picture is worth a thousand words, a
> sound is worth a thousand pictures." R. Murray Schafer via Bernie
> Krause.
>
> Yahoo! Groups Links
>
>
>
>
Wild Sanctuary
POB 536
Glen Ellen, CA 95442
707-996-6677
http://www.wildsanctuary.com
Google Earth zooms: http://earth.wildsanctuary.com
SKYPE: biophony
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