http://www.ingentaconnect.com/content/brill/beh/2010/00000147/F0020005
(Abstracts see below)
Odom, KJ & DJ Mennill (2010) Vocal duets in a nonpasserine: an examination
of territory defence and neighbourstranger discrimination in a neighbourhood
of barred owls. Behaviour 147: 619-639.
Mundinger, PC (2010) Behaviour genetic analysis of selective song learning
in three inbred canary strains. Behaviour 147: 705-723.
Patton, TB, G Szafranski T Shimizu (2010) Male pigeons react differentially
to altered facial features of female pigeons. Behaviour 147: 757-773.
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Abstracts
Odom, KJ & DJ Mennill (2010) Vocal duets in a nonpasserine: an examination
of territory defence and neighbourstranger discrimination in a neighbourhood
of barred owls. Behaviour 147: 619-639.
Mated pairs of animals in many taxa coordinate their vocalizations into
duets, yet most research on duetting has focused on songbirds. Here we
examine the duetting behaviour of barred owls (Strix varia) by addressing
three questions: (1) Do owl duets play a role in territorial interactions?
(2) Do owls discriminate between duets of neighbours versus strangers? (3)
Do duets play a role in extended communication among a neighbourhood of
owls? We simulated territorial encounters by broadcasting duets of adjacent,
territory-holding owls (neighbours) and distant owls (strangers). We
assessed responses to playback using a 3.5-km transect of automated
recording devices. We compared vocal activity during a pre-playback period
and following both playback treatments for the focal pair, their neighbours,
and more distant owls within the neighbourhood. After playback, focal owls
gave significantly more duets, vocalized for a longer duration, and
emphasized different call types compared to the pre-playback period,
demonstrating that barred owls use duets in territory defence. Focal owls
did not respond significantly differently to neighbours versus strangers. At
the neighbourhood level, owls did not behave differently during silent
pre-playback periods or post-playback periods. Our results suggest barred
owl duets function primarily in immediate confrontations during territorial
conflicts.
Mundinger, PC (2010) Behaviour genetic analysis of selective song learning
in three inbred canary strains. Behaviour 147: 705-723.
Thirty-three male canaries were reared as isolates in acoustic chambers.
Each male's sexchromosomes and autosomal background were known to strain.
The research included two experiments. One tested the hypothesis that the
low-pitched songs of waterslager canaries is due to a partial hearing
deficit in the high frequency range of their hearing, limiting learning
high-pitched syllables. That hypothesis was falsified and the apparent cause
for the low-pitched songs was uncovered in the second experiment. That
experiment tutored the males with a tutor tape that offered six different
canary songs to learn from. The experimental subjects included roller,
waterslager, and border canaries, their hybrids and backcrosses. The
selective learning of each genetically different group was closely
associated with their specific genetic background, and the results revealed
that roller and waterslager canaries have very different genetic mechanisms
affecting their song learning, and that a waterslager, recessive, autosomal
factor, when homozygous, was associated with that strain's low-pitched
songs. On the other hand, the low-pitched songs of roller canaries were
primarily affected by a recessive sex-linked factor. Border canary selective
learning was biased toward learning the higher-pitched syllables and tours
characteristic of the songs of border and other type canary strains.
Patton, TB, G Szafranski T Shimizu (2010) Male pigeons react differentially
to altered facial features of female pigeons. Behaviour 147: 757-773.
Male pigeons exhibit robust courtship to the head of a female, but not so
much to the body. The specific features in the female head which are
critical for triggering courtship from males remain unclear. We examined
this issue by studying preference behaviour of male pigeons between a pair
of photographic images of female conspecifics: a series of normal female
faces and a series of digitally altered facial features. Preference was
determined by measuring the duration of male courtship 'coo' responses near
each of these images. Males preferred intact females compared to those
missing the eyes and beak. They also responded less when only the eyes and
beak were visible without the head, suggesting that these local features
were important, yet more effective when embedded in the context of the head
than when they were not. Enlarging or removing the beak had a significant
impact on preference, whereas manipulating the eyes had a weaker effect.
Finally, males exhibited no preference between normal females and those that
had spatially rearranged eyes and beak. These results suggest that pigeons
naturally attend to the local features of the head, but not to the spatial
configuration, for conspecific recognition.
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