Marcello Siniscalchi, Rita Lusito, Raffaella Sasso & Angelo Quaranta (2012):
Are temporal features crucial acoustic cues in dog vocal recognition? Anim.
Cogn. 15(5), 815-821.
Abstract: To investigate the perceptual mechanisms underlying conspecific
vocal recognition in canine species, eighteen dogs were presented with
playbacks of normal and reversed versions of typical dog vocalizations.
Auditory perception was analysed using the head-turn paradigm, a
non-invasive technique extensively employed to study hemispheric
specializations for processing conspecific vocalizations in primates. The
results revealed that dogs usually turn their heads with the right ear
leading (left hemisphere activation) in response to the forward version of
their typical calls, and with either no bias and the left ear leading (right
hemisphere activation) in response to the reversed call versions. Overall,
our findings suggest that temporal features are determinant auditory cues
for call sound recognition in dogs, and support earlier findings of the role
of the left hemisphere in the analyses of intraspecific communication.
URL: http://link.springer.com/article/10.1007%2Fs10071-012-0506-x
For reprints please contact Marcello Siniscalchi (email:
Femke J. Pflüger & Claudia Fichtel (2012): On the function of redfronted
lemur?s close calls. Anim. Cogn. 15(5), 823-831.
Abstract: In order to maintain group cohesion, many social mammals and birds
regularly produce close calls. In some primate species, close calls appear
to have a dual function: calls addressed at a broad class of targets serve
to maintain group cohesion, whereas the same calls directed at a specific
target serve to regulate subsequent social interactions. Redfronted lemurs
(Eulemur rufifrons) produce different types of close calls: grunts, long
grunts, hoos and meows. In order to study the function of these calls, we
conducted focal observations and vocal recordings from eight adult males and
females out of four social groups in Kirindy Forest, Western Madagascar.
Redfronted lemurs produce long grunts, hoos and meows at relatively low
rates during foraging, resting or group movements, respectively. Grunts were
given most often and more or less constantly during foraging and traveling.
Calling rate increased when the risk of separation increased and may thus
promote group cohesion. Grunts given during approaches of other group
members resulted more often in friendly interactions than approaches that
were not accompanied by a grunt. Thus, redfronted lemurs produce specific
but also generic contact calls, whereas the latter calls have a dual
function that varies depending on the addressed audience: they act as an
auditory beacon to maintain group cohesion and serve as signals of benign
intent to avoid costly conflicts and facilitating social interactions.
URL: http://link.springer.com/article/10.1007%2Fs10071-012-0507-9
For reprints please contact Femke J. Pflüger (email:
Claudia A. F. Wascher, Georgine Szipl, Markus Boeckle & Anna Wilkinson
(2012): You sound familiar: carrion crows can differentiate between the
calls of known and unknown heterospecifics. Anim. Cogn. 15(5), 1015-1019.
Abstract: In group-living animals, it is adaptive to recognize conspecifics
on the basis of familiarity or group membership as it allows association
with preferred social partners and avoidance of competitors. However,
animals do not only associate with conspecifics but also with
heterospecifics, for example in mixed-species flocks. Consequently,
between-species recognition, based either on familiarity or even individual
recognition, is likely to be beneficial. The extent to which animals can
distinguish between familiar and unfamiliar heterospecifics is currently
unclear. In the present study, we investigated the ability of eight carrion
crows to differentiate between the voices and calls of familiar and
unfamiliar humans and jackdaws. The crows responded significantly more often
to unfamiliar than familiar human playbacks and, conversely, responded more
to familiar than unfamiliar jackdaw calls. Our results provide the first
evidence that birds can discriminate between familiar and unfamiliar
heterospecific individuals using auditory stimuli.
URL: http://link.springer.com/article/10.1007%2Fs10071-012-0508-8
For reprints please contact Claudia A. F. Wascher (email:
Amélie L. Vergne, Thierry Aubin, Samuel Martin & Nicolas Mathevon (2012):
Acoustic communication in crocodilians: information encoding and species
specificity of juvenile calls. Anim. Cogn. 15(6), 1095-1109.
Abstract: In the Crocodylia order, all species are known for their ability
to produce sounds in several communication contexts. Though recent
experimental studies have brought evidence of the important biological role
of young crocodilian calls, especially at hatching time, the juvenile vocal
repertoire still needs to be clarified in order to describe thoroughly the
crocodilian acoustic communication channel. The goal of this study is to
investigate the acoustic features (structure and information coding) in the
contact call of juveniles from three different species (Nile crocodile
Crocodylus niloticus, Black caiman, Melanosuchus niger and Spectacled
caiman, Caiman crocodilus). We have shown that even though substantial
structural differences exist between the calls of different species, they do
not seem relevant for crocodilians. Indeed, juveniles and adults from the
species studied use a similar and non-species-specific way of encoding
information, which relies on frequency modulation parameters. Interestingly,
using conditioning experiments, we demonstrated that this tolerance in
responses to signals of different acoustic structures was unlikely to be
related to a lack of discriminatory abilities. This result reinforced the
idea that crocodilians have developed adaptations to use sounds efficiently
for communication needs.
URL: http://link.springer.com/article/10.1007%2Fs10071-012-0533-7
For reprints please contact Nicolas Mathevon (email:
Hsiao-Wei Tu & Robert J. Dooling (2012): Perception of warble song in
budgerigars (Melopsittacus undulatus): evidence for special processing.
Anim. Cogn. 15(6), 1151-1159.
Abstract: The long, rambling warble song of male budgerigars is composed of
a large number of acoustically complex elements uttered in streams lasting
minutes a time and accompanied by various courtship behaviors. Warble song
has no obvious sequential structure or patterned repetition of elements,
raising questions as to which aspects of it are perceptually salient,
whether budgerigars can detect changes in natural warble streams, and to
what extent these capabilities are species-specific. Using operant
conditioning and a psychophysical paradigm, we examined the sensitivity of
budgerigars, canaries, and zebra finches to changes in long (>6 min) natural
warble sequences of a male budgerigar. All three species could detect a
single insertion of pure tones, zebra finch song syllables, budgerigar
contact calls, or warble elements from another budgerigar?s warble. In each
case, budgerigars were more sensitive to these changes than were canaries or
finches. When warble elements from the ongoing warble stream were used as
targets and inserted, out of order, into the natural warble stream so that
the only cue available was the violation of the natural ordering of warble
elements, only budgerigars performed above chance. When the experiment was
repeated with all the ongoing warble stream elements presented in random
order, the performance of budgerigars fell to chance. These results show
species-specific advantages in budgerigars for detecting acoustic changes in
natural warble sequences and indicate at least a limited sensitivity to
sequential rules governing the structure of their species-specific warble
songs.
URL: http://link.springer.com/article/10.1007%2Fs10071-012-0539-1
For reprints please contact Hsiao-Wei Tu (email:
Kind regards
Sonja Amoser
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Dr. Sonja Amoser
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