Abstracts below
www.ingentaconnect.com/content/brill/beh/2009/00000146/00000008
Kaiser, K & JL Hammers (2009) The effect of anthropogenic noise on male
advertisement call rate in the neotropical treefrog, Dendropsophus
triangulum. Behaviour 146: 1053-1069.
Barker, NKS, T Dabelsteen & DJ Mennill (2009) Degradation of male and female
rufous-and-white wren songs in a tropical forest: effects of sex, perch
height, and habitat. Behaviour 146: 1093-1122.
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Abstracts
Kaiser, K & JL Hammers (2009) The effect of anthropogenic noise on male
advertisement call rate in the neotropical treefrog, Dendropsophus
triangulum. Behaviour 146: 1053-1069.
Anthropogenic change such as road construction and subsequent traffic noise
in pristine habitats has been shown to be detrimental to a range of
vertebrate taxa. The effect of anthropogenic noise on anuran communication
is not well known, and has only recently been a topic of investigation. We
tested the effect of anthropogenic noise on the calling behaviour of the
Amazonian treefrog Dendropsophus triangulum. We performed four experiments.
We first presented frogs with the noise of a pre-recorded motorcycle engine,
and recorded the call rates of focal frogs for 5 min, then for another 5 min
during which they were presented with a broadcast of noise, and again for 5
min post-stimulus. We repeated this experiment using music as the stimulus.
We then tested the effect of intermittent engine noise, recording baseline
call rate and response to six cycles of intermittent noise. In all
experiments, call rates nearly doubled during playbacks. Finally, we
compared frogs' responses to anthropogenic noise to responses to chorus
noise broadcast at the same intensity; call rates did not differ between
treatments. These results demonstrate a clear effect of exogenous noise on
male D. triangulum.
Barker, NKS, T Dabelsteen & DJ Mennill (2009) Degradation of male and female
rufous-and-white wren songs in a tropical forest: effects of sex, perch
height, and habitat. Behaviour 146: 1093-1122.
We performed a song transmission experiment to investigate the effects of
distance, song post height, receiver perch height, signaller sex, and
microhabitat on song degradation in rufous-and-white wrens (Thryothorus
rufalbus), a neotropical duetting songbird. We quantified the effects of
these factors on excess attenuation, signal-to-noise ratio, tail-to-signal
ratio, and blur ratio of male and female songs. As expected, song
degradation increased with distance between signaller and receiver. Songs
transmitted best when emitted from moderate heights (5-7 m), although this
pattern varied with receiver distance, receiver height and microhabitat. The
patterns regarding receiver height were subtle and inconsistent, but
receivers may maximise their ability to hear male and female songs when
perched at a height of 7 m and 5 m, respectively. Female songs were
generally more degraded than male songs. Rufous-and-white wren songs
appeared more attenuated in open field than forest habitats, but
microhabitat conditions within the forests exerted a strong influence on
song degradation. These findings match previous studies showing an effect of
distance, song post height, and habitat, but contrast with other research by
showing a minimal effect of receiver perch height. This study represents the
first detailed investigation of differences in song transmission between
males and females.
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