Sorry for late posting!
Behaviour 143, 2
http://www.ingentaconnect.com/content/brill/beh/2006/00000143/00000002;jsessionid=1n4qhjm7s7ilk.henrietta
Abstracts below
Voigt, C, S Leitner & M Gahr (2006) Repertoire and structure of duet and solo
songs in cooperatively breeding white-browed sparrow weavers. Behaviour 143:
159-182.
Harris, TR (2006) Within- and among-male variation in roaring by black and
white colobus monkeys (Colobus guereza): What does it reveal about function?
Behaviour 143: 197-218.
Gros-Louis, J, DJ White, AP King & MJ West (2006) Do juvenile males affect
adult males' reproductive success in brown-headed cowbirds (Molothrus ater)?
Behaviour 143: 219-237.
Tougaard, J & N Eriksen (2006) Analysing differences among animal songs
quantitatively by means of the Levenshtein distance measure. Behaviour 143:
239-252.
Eckerle, KP & CF Thompson (2006) Mate choice in house wrens: nest cavities
trump male characteristics. Behaviour 143: 253-271.
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Abstracts
Voigt, C, S Leitner & M Gahr (2006) Repertoire and structure of duet and solo
songs in cooperatively breeding white-browed sparrow weavers. Behaviour 143:
159-182.
White-browed sparrow weavers (Plocepasser mahali) are cooperatively breeding
songbirds of eastern and southern Africa that live in small groups year-round
consisting of a dominant breeding pair, and subordinate, non-breeding males and
females. This species possesses an elaborate vocal communication system: solo
songs are exclusively produced by the dominant male, duet songs are mainly
produced by the dominant pair, and chorus songs, similar in syllable structure
and temporal pattern to duet songs, are produced by all group members. We
analysed songs of males and females with known social status recorded from
different colonies in Zimbabwe and complemented these data by studying songs of
captive birds at our institute. Solo songs are produced in one performance at
dawn during the breeding season. Recordings of captive males on consecutive
days revealed that males sing in a single solo performance 88.4 ± 4.1% of their
total solo song repertoire. This suggests that dominant mal
es recorded in Zimbabwe have a solo song repertoire of 67.0 ± 4.0 syllables,
which is similar in size to those of captive males (58.3 ± 3.7 syllables).
Repertoire sizes of both free-living and captive males are not correlated with
the length of the solo song performance. Duetting is both antiphonal and in
unison. Dominant males and females appear to have similar sized duet
repertoires (51.9 ± 2.1 syllables). Recordings from captive pairs suggest that
75-98% of the repertoire is shared with higher syllable sharing in more
experienced pairs. Since all group members engage in duets and chorus singing,
we estimate that each subordinate male and female shares the duet syllable
repertoire with the breeding pair. For dominant males, the duet syllables are
widely distinct from those of the solo songs; of their total syllable
repertoire only 2.1% occur in both repertoires. Further, solo song and duet
song differ in the temporal organisation.
Harris, TR (2006) Within- and among-male variation in roaring by black and
white colobus monkeys (Colobus guereza): What does it reveal about function?
Behaviour 143: 197-218.
To test hypotheses about loud call function, researchers have typically used
playback experiments and/or analyzed the contexts in which calls are produced.
Analyzing the variation within and among individuals' loud calls may also
provide insights about their function, including advertisement of callers'
fighting abilities. This study tests whether some male black and white colobus
monkeys (Colobus guereza, 'guerezas') indicate their willingness to defend
access to important feeding areas and/or mates by increasing the number of
roars they produce/chorus, their roar lengths, and/or overall roaring effort.
It also tests whether mean values for these roaring variables indicate male
fighting ability. My assistants and I followed six guereza groups for three
months each at Kanyawara, Kibale National Park, Uganda. I recorded males'
morning chorus roars and used data on roars, intergroup aggression, feeding,
and proximity of females to ovulation to test hypotheses about roaring var
iation. I show that males were the main participants in intergroup aggression,
the six study groups can be ranked in a linear dominance hierarchy, and group
rank (effectively male rank) predicts and varies positively with how long males
roar, as well as overall roaring effort. I provide evidence that some males
roar longer when their groups' females are in close proximity to presumptive
ovulation. There was relatively little evidence that males roar more when near
important feeding areas. Males in higher and lower ranking groups may have
different roaring strategies in the presence of important resources, but
further studies are needed to fully test this idea. While this study may not
provide strong evidence for either a direct mate or food defense function of
roars, it shows that roars may advertise a male's ability to defend mates
and/or food.
Gros-Louis, J, DJ White, AP King & MJ West (2006) Do juvenile males affect
adult males' reproductive success in brown-headed cowbirds (Molothrus ater)?
Behaviour 143: 219-237.
The present study was motivated by a recent anomalous finding between
individual competitive performance and reproductive output in brown-headed
cowbirds (Molothrus ater). White et al. (2002c) found that adult males who were
housed with juveniles outcompeted adults who were housed with other adults when
they were brought together to compete for mating opportunities. Although the
males in groups that contained both juveniles and adults appeared to be better
in securing reproductive opportunities, these groups were found to produce
fewer eggs than groups with all adult males (White et al., 2002c). Because
adult males were housed with juveniles, it was unclear whether the lower egg
production was simply due to juveniles not reproducing or whether the adult
males suffered decreased reproductive output. Is the presence of juvenile males
advantageous to adult males or do they suffer reproductive consequences? In the
current study, we studied four groups of captive cowbirds that di
ffered only in the presence of juvenile males to determine what influence
juvenile males have on adult male reproduction. At the end of the breeding
season, we performed microsatellite parentage analysis on these four groups.
Females in the two groups that contained juvenile and adult males produced
fewer fertile eggs compared to females in the all-adult male aviaries.
Furthermore, parentage analysis revealed that female reproductive patterns were
similar in the two conditions, but females in the juvenile-adult aviaries
produced fewer fertile eggs. Similarly, the males in the juvenile-adult
aviaries showed a similar pattern of reproductive success as the males in the
all-adult male aviaries, but had consistently lower reproductive output.
Tougaard, J & N Eriksen (2006) Analysing differences among animal songs
quantitatively by means of the Levenshtein distance measure. Behaviour 143:
239-252.
The Levenshtein or string edit distance is an objective measure of the
difference between two strings of elements. Levenshtein distance analysis has
previously been applied to humpback whale songs, where it provided a
quantitative measure of song change from year to year. This analysis is
extended and a first approach to a robust statistical test is developed. The
statistical test addresses the central issue whether two groups of songs
(either from different individuals, different groups or different years) belong
to the same population of songs or are significantly different. This is
accomplished through derivation of the Kohonen median song sequence, which has
the smallest possible summed Levenshtein distance to all songs of the group. By
a simple t-test or nonparametric equivalent it is tested whether the median
distance to the Kohonen median song sequence of a second group is significantly
larger, which indicates that the groups are different. The test is expanded to
han
dle multiple comparisons among several groups of songs.
Eckerle, KP & CF Thompson (2006) Mate choice in house wrens: nest cavities
trump male characteristics. Behaviour 143: 253-271.
When male birds defend all-purpose breeding territories, females may select
mates based on indicators of male or territory quality, or both. However, in
non-experimental studies, it can be difficult to determine which traits females
prefer because measures of male and territory quality frequently covary. We
conducted a series of studies to investigate the traits female house wrens
(Troglodytes aedon) use to select a social mate when each male is provided with
nest sites of equal quality (i.e., nestboxes). We first compared the phenotypic
and territory vegetation traits of males with the time it took them to secure a
social mate after returning from the wintering grounds. Male arrival and
pairing date were positively correlated and early-arriving males were in better
condition and occupied territories in more preferred vegetation than
late-arriving males. To test the hypothesis that early-arriving males possessed
phenotypic or territory traits that led to their pairing more q
uickly than late-arriving males, we removed all females after pairs had been
established and determined male success in attracting new mates. Male
settlement and pairing date with replacement females were not correlated as had
been male settlement and pairing date with original females, and male
time-to-pairing was not correlated with male song rate, condition index, or
territory vegetation. When we manipulated the abundance of nest sites on
territories, after males settled but before females arrived, male
time-to-pairing, independent of male condition index or territory vegetation,
was negatively related to the number of nest sites on a male's territory. These
results suggest that under natural conditions females rely on nest-site
quantity and, likely, quality when selecting a social mate.
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