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Undirected (solitary) birdsong in female and male blue-capped cordon-bleus (Uraeginthus cyanocephalus) and its endocrine correlates.

Geberzahn N, Gahr M - PLoS ONE (2011)

Bottom Line: However, in both sexes the overall plasma testosterone concentrations were low (ca. 300 pg/ml) and did not correlate with the sexually dimorphic song motor pattern.Despite such low concentrations, the increase in the rate of solitary song coincided with an increase in the level of testosterone.Our findings suggest that the occurrence of solitary song but not its motor pattern might be under the control of testosterone in female and male cordon-bleus.

View Article: PubMed Central - PubMed

Affiliation: Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany. nicole.geberzahn@u-psud.fr

ABSTRACT

Background: Birdsong is a popular model system in research areas such as vocal communication, neuroethology or neuroendocrinology of behaviour. As most research has been conducted on species with male-only song production, the hormone-dependency of male song is well established. However, female singing and its mechanisms are poorly understood.

Methodology/principal findings: We characterised the song and its endocrine correlates of blue-capped cordon-bleus (Uraeginthus cyanocephalus), a species in which both sexes sing. Like other estrildids, they produce directed song during courtship and undirected (or solitary) song in isolation, i.e. when the mate is not visible or absent. We compare solitary song of blue-capped cordon-bleus to published descriptions of the song of its relative, the zebra finch (Taeniopygia guttata). Solitary song of cordon-bleus shared some overall song features with that of zebra finches but differed in spectro-temporal song features, sequential stereotypy and sequential organisation. The song of cordon-bleus was dimorphic with respect to the larger size of syllable repertoires, the higher song duration and the lower variability of pitch goodness (measuring the pureness of harmonic sounds) in males. However, in both sexes the overall plasma testosterone concentrations were low (ca. 300 pg/ml) and did not correlate with the sexually dimorphic song motor pattern. Despite such low concentrations, the increase in the rate of solitary song coincided with an increase in the level of testosterone. Furthermore, the latency to start singing after the separation from the mate was related to hormone levels.

Conclusions/significance: Our findings suggest that the occurrence of solitary song but not its motor pattern might be under the control of testosterone in female and male cordon-bleus.

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Related in: MedlinePlus

Solitary song of female and male blue-capped cordon-bleus.Each subject sang an individually characteristic song consisting of a unique sequence of syllables with some rendition to rendition variation. Sexual dimorphism in the song was subtle (cf. Table 2). Shown are images of spectral derivatives of solitary song (frequency as a function of time). The left panel (a–c) gives three examples of song renditions for each of three female subjects; the right panel (d–f) gives three examples of song renditions for each of three male subjects. Black bars on the bottom of each top image indicate syllables delineated using a 23 db threshold for amplitude and a −2.1 threshold for entropy in the features batch window of SAP. For the top images of (a) and (d), syllable labels are indicated as follows, i: introductory syllable, A, B, C etc. subsequently occurring syllable types. Note the immediately repeated syllables C, O and Q in (d). In the third rendition from the top of (f) a motif consisting of three syllables that are repeated within the same song is highlighted by a black box. See supplementary material for sound files for (a) and (d).
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pone-0026485-g001: Solitary song of female and male blue-capped cordon-bleus.Each subject sang an individually characteristic song consisting of a unique sequence of syllables with some rendition to rendition variation. Sexual dimorphism in the song was subtle (cf. Table 2). Shown are images of spectral derivatives of solitary song (frequency as a function of time). The left panel (a–c) gives three examples of song renditions for each of three female subjects; the right panel (d–f) gives three examples of song renditions for each of three male subjects. Black bars on the bottom of each top image indicate syllables delineated using a 23 db threshold for amplitude and a −2.1 threshold for entropy in the features batch window of SAP. For the top images of (a) and (d), syllable labels are indicated as follows, i: introductory syllable, A, B, C etc. subsequently occurring syllable types. Note the immediately repeated syllables C, O and Q in (d). In the third rendition from the top of (f) a motif consisting of three syllables that are repeated within the same song is highlighted by a black box. See supplementary material for sound files for (a) and (d).

Mentions: In a first step, we extracted several acoustic parameters using SAP. To this end, syllables were automatically delineated using a constant threshold for amplitude (23 dB) and entropy (−2.1) in the features batch window (Fig. 1). These thresholds turned out to be most appropriate for this species after comparing delineation with different settings.


Undirected (solitary) birdsong in female and male blue-capped cordon-bleus (Uraeginthus cyanocephalus) and its endocrine correlates.

Geberzahn N, Gahr M - PLoS ONE (2011)

Solitary song of female and male blue-capped cordon-bleus.Each subject sang an individually characteristic song consisting of a unique sequence of syllables with some rendition to rendition variation. Sexual dimorphism in the song was subtle (cf. Table 2). Shown are images of spectral derivatives of solitary song (frequency as a function of time). The left panel (a–c) gives three examples of song renditions for each of three female subjects; the right panel (d–f) gives three examples of song renditions for each of three male subjects. Black bars on the bottom of each top image indicate syllables delineated using a 23 db threshold for amplitude and a −2.1 threshold for entropy in the features batch window of SAP. For the top images of (a) and (d), syllable labels are indicated as follows, i: introductory syllable, A, B, C etc. subsequently occurring syllable types. Note the immediately repeated syllables C, O and Q in (d). In the third rendition from the top of (f) a motif consisting of three syllables that are repeated within the same song is highlighted by a black box. See supplementary material for sound files for (a) and (d).
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3198478&req=5

pone-0026485-g001: Solitary song of female and male blue-capped cordon-bleus.Each subject sang an individually characteristic song consisting of a unique sequence of syllables with some rendition to rendition variation. Sexual dimorphism in the song was subtle (cf. Table 2). Shown are images of spectral derivatives of solitary song (frequency as a function of time). The left panel (a–c) gives three examples of song renditions for each of three female subjects; the right panel (d–f) gives three examples of song renditions for each of three male subjects. Black bars on the bottom of each top image indicate syllables delineated using a 23 db threshold for amplitude and a −2.1 threshold for entropy in the features batch window of SAP. For the top images of (a) and (d), syllable labels are indicated as follows, i: introductory syllable, A, B, C etc. subsequently occurring syllable types. Note the immediately repeated syllables C, O and Q in (d). In the third rendition from the top of (f) a motif consisting of three syllables that are repeated within the same song is highlighted by a black box. See supplementary material for sound files for (a) and (d).
Mentions: In a first step, we extracted several acoustic parameters using SAP. To this end, syllables were automatically delineated using a constant threshold for amplitude (23 dB) and entropy (−2.1) in the features batch window (Fig. 1). These thresholds turned out to be most appropriate for this species after comparing delineation with different settings.

Bottom Line: However, in both sexes the overall plasma testosterone concentrations were low (ca. 300 pg/ml) and did not correlate with the sexually dimorphic song motor pattern.Despite such low concentrations, the increase in the rate of solitary song coincided with an increase in the level of testosterone.Our findings suggest that the occurrence of solitary song but not its motor pattern might be under the control of testosterone in female and male cordon-bleus.

View Article: PubMed Central - PubMed

Affiliation: Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany. nicole.geberzahn@u-psud.fr

ABSTRACT

Background: Birdsong is a popular model system in research areas such as vocal communication, neuroethology or neuroendocrinology of behaviour. As most research has been conducted on species with male-only song production, the hormone-dependency of male song is well established. However, female singing and its mechanisms are poorly understood.

Methodology/principal findings: We characterised the song and its endocrine correlates of blue-capped cordon-bleus (Uraeginthus cyanocephalus), a species in which both sexes sing. Like other estrildids, they produce directed song during courtship and undirected (or solitary) song in isolation, i.e. when the mate is not visible or absent. We compare solitary song of blue-capped cordon-bleus to published descriptions of the song of its relative, the zebra finch (Taeniopygia guttata). Solitary song of cordon-bleus shared some overall song features with that of zebra finches but differed in spectro-temporal song features, sequential stereotypy and sequential organisation. The song of cordon-bleus was dimorphic with respect to the larger size of syllable repertoires, the higher song duration and the lower variability of pitch goodness (measuring the pureness of harmonic sounds) in males. However, in both sexes the overall plasma testosterone concentrations were low (ca. 300 pg/ml) and did not correlate with the sexually dimorphic song motor pattern. Despite such low concentrations, the increase in the rate of solitary song coincided with an increase in the level of testosterone. Furthermore, the latency to start singing after the separation from the mate was related to hormone levels.

Conclusions/significance: Our findings suggest that the occurrence of solitary song but not its motor pattern might be under the control of testosterone in female and male cordon-bleus.

Show MeSH
Related in: MedlinePlus