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 i=
n the pipe gets to project his higher frequencies better ? That aside the i=
nstantaneous change in call type shows just how closely they are are connec=
ted 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 sho=
p 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 bo=
th
> 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
>
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> SKYPE: biophony
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