Please find the abstracts below
Wingelmaier, K, H Winkler, & E Nemeth (2007) Reed bunting (Emberiza
schoeniclus) males sing an 'all-clear' signal to their incubating females.
Behaviour 144: 195-206.
Wright, TF & CR Dahlin (2007) Pair duets in the yellow-naped amazon (Amazona
auropalliata): Phonology and syntax. Behaviour 144: 207-228.
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Abstracts:
Wingelmaier, K, H Winkler, & E Nemeth (2007) Reed bunting (Emberiza
schoeniclus) males sing an 'all-clear' signal to their incubating females.
Behaviour 144: 195-206.
While sexual functions of birdsong have been intensively investigated,
non-sexual functions have received less attention. After pair formation
males may sing to communicate with their established mates. Song aimed at
incubating and feeding females could serve as an 'all-clear' signal, showing
that there is no risk of predation and that it is safe for the female to
exit the nest or to feed the young. Females should therefore preferentially
leave nests when mates are singing nearby. Additionally, a vigilant male
near the nest site could protect the brood from potential risks like
predation and females could stay away longer for foraging. In this study, we
investigated aspects of male singing activity of reed buntings (Emberiza
schoeniclus) during incubation and feeding of nestlings after pair
formation. Exits of incubating females from the nest occurred significantly
more often than expected during male song output. When their mates were
singing at high rates, females stayed away longer for incubation breaks.
During the nestling period we found a high variation in male song output.
Males that sang more fed their young significantly less. This suggests that
time devoted to singing limits other activities such as feeding of
offspring. Male reed buntings could choose different strategies for paternal
investment: They either feed at high rates or they sing more to signal their
vigilance. Another reason for this trade-off might be a conflict between
paternal investment and territory defence or extrapair behaviour. However,
even if male song after pairing has additional sexual functions, we suggest
that non-sexually selected functions may be more common than expected.
Wright, TF & CR Dahlin (2007) Pair duets in the yellow-naped amazon (Amazona
auropalliata): Phonology and syntax. Behaviour 144: 207-228.
Pair duets are acoustically complex communication signals formed jointly by
members of a mated pair. Duets may serve multiple communication functions;
quantitative studies of the acoustic structure and organization of notes (or
'syntax') within duets are an important step in identifying these functions.
This study examined duets of the yellow-naped amazon (Amazona auropalliata)
at two sites in Costa Rica to determine the syntactical rules underlying
duet variation. Duets were composed of contact calls and three other note
types found only in duets. These latter note types were sex-specific, with
one type performed by females and the other two types by males. Sex-specific
notes were delivered antiphonally and in distinct pairs, with the male note
following and often overlapping that of the female. Note types appeared in a
strict sequential order in which each note could be repeated a variable
number of times or omitted entirely, a pattern previously termed
'combinatorial syntax'. Additionally, there was considerable variation in
acoustic parameters of notes within types. Many of these parameters varied
significantly with note order within a duet. These syntactical features
suggest a preliminary hypothesis that males and females encode different,
and possibly multiple, messages in their respective contributions to duets.
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Frank Veit, Ph D
Marine Mammal Research Coordinator
Archipelagos Institute
Poste Restante
85500 Patmos
Greece
Tel./Fax: +30 22750 41673
mob. : +30 6946447506
www.archipelago.gr
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