Not sure when this appeared in the print edition, but anyway, might be of i=
nterest.
Connor
Nocturnal tree frogs living in China have been found to possess extraordina=
ry vocal and
localization skills, comparable to dolphins, elephants and humans. A paper =
online in
Nature this week analyses the ultrasonic mating calls of the female torrent=
frog Odorrana
tormota to reveal a surprisingly well-developed acoustic communication syst=
em, which is
an adaptation to the noisy environment of rushing streams.
Vocalized mating calls play a key role in frog reproduction =97 male frogs =
are typically
dominant, advertising their virility, with the females tending to be more p=
assive,
occasionally producing a weak reciprocal call or rapping sounds during cour=
tship.
Although the females have an unusually well-developed vocal production syst=
em, whether
or not they produce calls in a communication system dominated by males has =
so far been
unclear.
Jun-Xian Shen and colleagues recorded the vocalizations of female frogs in =
a quiet,
darkened room using an ultrasonic microphone linked up to a computer. They =
found that,
just before ovulating, female frogs emit short, high-frequency ultrasonic s=
ignals distinct
from the males' advertisement calls. They then played back the female calls=
to examine
the response of the male frogs, and found that they both increased their ca=
lling activity
and approached the source of the noise. On hearing the female call, a male =
usually
oriented his body and made a long-distance hop towards the loudspeaker with=
remarkable precision.
The authors suggest that the torrent frogs may have developed this high-fre=
quency
ultrasonic system as a method of unambiguous communication in the presence =
of their
noisy habitat.
Author contact:
Jun-Xian Shen (Chinese Academy of Sciences, Beijing, China)
Tel: +86 10 6488 8542; E-mail:
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