Francisco J. Diego-Rasilla and Rosa M. Luengo (2007): Acoustic orientation
in the palmate newt, Lissotriton helveticus. Behav. Ecol. Sociobiol. 61,
1329?1335.
Abstract: Experiments reported here were carried out to investigate the use
of acoustic cues by palmate newts (Lissotriton helveticus) for orientation
and to study whether this behavior is learned, or whether two populations of
palmate newts that cohabit with different frog species (Iberian green frog,
Rana perezi, and European common brown frog, Rana temporaria) show different
phonotactic preferences. The orientation tests consisted of presenting a
control stimulus (white noise), a sympatric acoustic stimulus (calls of R.
perezi or R. temporaria, depending on the origin of newts), or an allopatric
stimulus (calls of natterjack toads, Bufo calamita, or R. perezi). Newts
were released in a circular arena, while the acoustic stimuli were presented
outside of the circular arena in four different compass orientation
directions (0, 90, 180 and 270°). In this study, we show that L. helveticus
performed positive phonotaxis toward the calls of R. perezi only when both
species shared habitat, orienting randomly when R. perezi was absent from
the newt?s natal population. Newts from both populations oriented randomly
when exposed to the allopatric and control acoustic stimuli. These results
suggest, for the first time, that recognition of the sympatric
heterospecific calls could be learned. However, newts sharing the breeding
pond with a population of R. temporaria oriented randomly when exposed to
the calls of this species. The fact that the breeding seasons of R.
temporaria and L. helveticus do not overlap in time does not allow the use
of R. temporaria calls as a guidance mechanism for migrating individuals of
L. helveticus.
URL: http://www.springerlink.com/content/64510q514205000r/
For reprints please contact: Francisco J. Diego-Rasilla (Email:
Moritz Weinbeer and Elisabeth K. V. Kalko (2007): Ecological niche and
phylogeny: the highly complex echolocation behavior of the trawling
long-legged bat, Macrophyllum macrophyllum. Behav. Ecol. Sociobiol. 61,
1337-1348.
Abstract: Bats produce echolocation signals that reflect the sensory tasks
they perform. In open air or over water, bats encounter few or no background
echoes (clutter). Echolocation of such bats is the primary cue for prey
perception and varies with the stage of approach to prey, typically
comprising search, approach, and terminal group calls. In contrast, bats
that glean stationary food from rough surfaces emit more uniform calls
without a distinct terminal group. They use echolocation primarily for
orientation in space and mostly need additional sensory cues for finding
food because clutter echoes overlap strongly with food echoes. Macrophyllum
macrophyllum is the only Neotropical leaf-nosed bat (Phyllostomidae) that
hunts in clutter-poor habitat over water. As such, we hypothesized that,
unlike all other members of its family, but similar to other trawling and
aerial insectivorous bats, M. macrophyllum can hunt successfully by using
only echolocation for prey perception. In controlled behavioral experiments
on Barro Colorado Island, Panamá, we confirmed that echolocation alone is
sufficient for finding prey in M. macrophyllum. Furthermore, we showed that
pattern and structure of echolocation signals in M. macrophyllum are more
similar to aerial and other trawling insectivorous bats than to close
phylogenetic relatives. Particularly unique among phyllostomid bats, we
found distinct search, approach, and terminal group calls in foraging M.
macrophyllum. Call structure, however, consisting of short, multiharmonic,
and steep frequency-modulated signals, closely resembled those of other
phyllostomid bats. Thus, echolocation behavior in M. macrophyllum is shaped
by ecological niche as well as by phylogeny.
URL: http://www.springerlink.com/content/7868628424408126/
For reprints please contact: Elisabeth K. V. Kalko (Email:
Gonçalo C. Cardoso, Paulo Gama Mota and Violaine Depraz (2007): Female and
male serins ( Serinus serinus ) respond differently to derived song traits.
Behav. Ecol. Sociobiol. 61, 1425-1436.
Abstract: We tested if male or female behavior towards manipulated song
indicates intra- or inter-sexual selection of two characteristics of serin
song that are extreme and evolutionarily derived in this species: high
frequency and fast syllable rate. In a first experiment, we monitored vocal
responses and attendance to song playbacks. Female behavior indicated a
preference for high-frequency song and suggested an aggressive function for
fast syllable rates, as fast songs inhibited vocal response. Males did not
show discrimination of frequency or syllable rate with this experimental
design. The second experiment used a simple approach/no approach design, and
in this experiment, males showed stronger discrimination between stimuli
than did females. Therefore, sex differences in discrimination appear not to
result from differences in perceptual abilities but from differences in the
context of stimulus presentation. The second experiment also supported a
role of song frequency in female choice, as the effect of frequency was
limited to females: males did not respond differently to song frequency and
approached high-frequency songs less than females did. Results of this
experiment also supported an aggressive function for fast syllable rates, as
the effect of fast songs did extend to male behavior. Taken together, our
results indicate that the high frequency and fast syllable rate of serin
song cannot result from a single selection process: while high frequency may
have evolved by inter-sexual selection, syllable rate provokes a pattern of
response that is more consistent with intra-sexual selection.
URL: http://www.springerlink.com/content/8g755r1510539g05/
For reprints please contact: Gonçalo C. Cardoso (Email:
Kind regards
Sonja
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University of Vienna, Dept. of Behavioural Biology
Sonja Amoser
PhD
Althanstrasse 14
1090 Vienna
Austria
tel: +43 (1) 4277 54467
fax: +43 (1) 4277 54506
mobile: +43 (664) 500 61 06
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