Abstracts below
Gogoleva, SS, IA Volodin, EV Volodina, AV Kharlamova & LN Trut (2010)
Sign and strength of emotional arousal: vocal correlates of positive and
negative attitudes to humans in silver foxes (Vulpes vulpes). Behaviour
147: 1713-1736.
Richardson, C, P Joly, JP Lena, S Plenet & T Lengagne (2010) The
challenge of finding a high-quality male: a treefrog solution based on
female assessment of male calls. Behaviour 147: 1737-1752.
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Abstracts:
Gogoleva, SS, IA Volodin, EV Volodina, AV Kharlamova& LN Trut (2010) Sign and
strength of emotional arousal: vocal correlates of positive and negative attitudes
to humans in silver foxes (Vulpes vulpes). Behaviour 147: 1713-1736.
The hypothesis of similarity in trends of acoustic characteristics
regardless of the sign of emotional arousal, positive or negative, has
been advanced based on human vocalizations. For non-human mammals,
testing is complicated because the same stimulus cannot evoke opposite
(positive and negative) internal states, to trigger the respective
vocalizations. To resolve this concern, we designed an experimental
procedure using Tame and Aggressive strains of silver foxes, with
genetically predetermined positive or negative emotional responses to
humans respectively. We analyzed features of vocalizations produced by
callers at different fox-human distances, assuming changes in vocal
responses reflect the shifts of human-related positive arousal in Tame
foxes and human-related negative arousal in Aggressive foxes. Both
strains showed similar trends for changes in calling rate and proportion
of time spent vocalizing toward higher levels in response to greater
emotional arousal, positive in Tame foxes and negative in Aggressive
foxes. At the same time, strains showed distinctive trends for the
proportions of different call types and maximum amplitude frequency. We
infer that the variables with similar trends reflect the strength of
emotional arousal, regardless of triggering internal states, whereas
variables with distinctive trends are specifically related to the sign
of emotion in silver fox.
Richardson, C, P Joly, JP Lena, S Plenet& T Lengagne (2010) The challenge of
finding a high-quality male: a treefrog solution based on female assessment of male
calls. Behaviour 147: 1737-1752.
In the context of sexual selection through mate choice, it has recently
been suggested that the effectiveness of intersexual communication is
affected not only by the honesty of male sexual signals but also by the
number of signal components simultaneously used to convey information.
We investigated female use of acoustic components in the chorusing
treefrog/Hyla arborea/ using two-choice phonotaxis tests. Females
showed a significant preference for higher call rates and calls of short
duration, as well as for higher call amplitudes. They also favoured
lower peak frequencies. Since this call characteristic was negatively
correlated with body weight, such a preference should lead to their
selecting larger males. Females also exhibited a marginal preference for
longer call bouts. The reliability of the multiple call components
involved in mate choice in/H. arborea/ are discussed, as well as the validity
of these results for mate choice in the natural context of a noisy anuran
chorus.
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