Kseniya O. Efremova, Ilya A. Volodin, Elena V. Volodina, Roland Frey,
Ekaterina N. Lapshina & Natalia V. Soldatova (2011): Developmental changes
of nasal and oral calls in the goitred gazelle Gazella subgutturosa, a
nonhuman mammal with a sexually dimorphic and descended larynx.
Naturwissenschaften 98 (11), 919-931.
Abstract: In goitred gazelles (Gazella subgutturosa), sexual dimorphism of
larynx size and position is reminiscent of the case in humans, suggesting
shared features of vocal ontogenesis in both species. This study
investigates the ontogeny of nasal and oral calls in 23 (10 male and 13
female) individually identified goitred gazelles from shortly after birth up
to adolescence. The fundamental frequency (f0) and formants were measured as
the acoustic correlates of the developing sexual dimorphism. Settings for
LPC analysis of formants were based on anatomical dissections of 5
specimens. Along ontogenesis, compared to females, male f0 was consistently
lower both in oral and nasal calls and male formants were lower in oral
calls, whereas the first two formants of nasal calls did not differ between
sexes. In goitred gazelles, significant sex differences in f0 and formants
appeared as early as the second week of life, while in humans they emerge
only before puberty. This result suggests different pathways of vocal
ontogenesis in the goitred gazelles and in humans.
URL: http://www.springerlink.com/content/g53270l808215g4l/
For reprints please contact Ilya Volodin (email:
Thomas Wesener, Jörn Köhler, Stefan Fuchs & Didier van den Spiegel (2011):
How to uncoil your partner??mating songs? in giant pill-millipedes
(Diplopoda: Sphaerotheriida). Naturwissenschaften 98 (11), 967-975.
Abstract: The stridulation of the giant pill-millipede genus Sphaerotherium
from South Africa, one of only three groups of millipedes that produce
sounds, was studied. One hundred one stridulation series of a total of nine
different species (Sphaerotherium dorsaloide, Sphaerotherium hanstroemi,
Sphaerotherium mahaium, Sphaerotherium similare, Sphaerotherium punctulatum,
Sphaerotherium convexitarsum, Sphaerotherium dorsale, Sphaerotherium
rotundatum, and Sphaerotherium perbrincki) were analyzed. Stridulation
sounds are produced only with a special field of ribs on the posterior
surface of the posterior telopod, which is actively moved over a field of
sclerotized nubs on the inner margin of the anal shield. The Sphaerotherium
male usually stridulates only when in contact with a female to initiate
mating. This seems to prevent the female from volvating into a ball or
stimulate the female to uncoil when already rolled in. The sound analyzes
revealed a broad frequency spectrum in all stridulation sounds produced,
without obvious differences in frequency distribution among species.
However, the temporal pattern of the stridulation varies greatly between
species and seems to be species-specific, arguing for a species recognition
function of the stridulation during courtship behavior. A single species (S.
punctulatum) was found to stridulate during mating while three species also
show postcopulatory stridulation. Apparently, pill-millipedes are not
capable of acoustic perception, as no hearing organs are known, indicating
that the communication is mainly based on perception of temporal vibration
patterns, and not of the acoustic signal itself. The need to overcome the
rolling-in reflex of the female is developed as a hypothesis why
stridulation exists only in millipedes able to coil into a ball, and
apparently evolved four times independently in the superorder Oniscomorpha.
URL: http://www.springerlink.com/content/u3h307757876t723/
For reprints please contact Thomas Wesener (email:
Lauren M. Guillette & Christopher B. Sturdy (2011): Individual differences
and repeatability in vocal production: stress-induced calling exposes a
songbird's personality. Naturwissenschaften 98 (11), 977-981.
Abstract: Recent research in songbirds has demonstrated that male singing
behavior varies systematically with personality traits such as exploration
and risk taking. Here we examine whether the production of bird calls, in
addition to bird songs, is repeatable and related to exploratory behavior,
using the black-capped chickadee (Poecile atricapillus) as a model. We
assessed the exploratory behavior of individual birds in a novel environment
task. We then recorded the vocalizations and accompanying motor behavior of
both male and female chickadees, over the course of several days, in two
different contexts: a control condition with no playback and a stressful
condition where chick-a-dee mobbing calls were played to individual birds.
We found that several vocalizations and behaviors were repeatable within
both a control and a stressful context, and across contexts. While there was
no relationship between vocal output and exploratory behavior in the control
context, production of alarm and chick-a-dee calls in the stressful
condition was positively associated with exploratory behavior. These
findings are important because they show that bird calls, in addition to
bird song, are an aspect of personality, in that calls are consistent both
within and across contexts, and covary with other personality measures
(exploration).
URL: http://www.springerlink.com/content/64p717325779n15u/
For reprints please contact Christopher Sturdy (email:
Kind regards
Sonja
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Dr. Sonja Amoser
Steinrieglstraße 286
3400 Weidlingbach
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