Song sharing and repertoire size in the sedge warbler, Acrocephalus schoenobaenus: changes within and between years

The complex song of the male sedge warbler functions mainly in sexual attraction and the evolution of repertoire size is driven primarily by female choice. As male song ceases upon pairing, male–male singing interactions are relatively brief and have not been studied to our knowledge. This study shows that young males in their first breeding season shared significantly more syllables with their nearest neighbour than with their fathers or more distant males. Moreover, daily recordings revealed that rapid learning and modification of syllable repertoires occurred, resulting in a progressive increase in sharing within just a few days. This does not lead to a gradual increase in repertoire size as some syllables are dropped and new ones are acquired. This turnover process allows males to share syllables with their neighbours, whilst repertoire size, known to be important in female choice, remains relatively constant in any one year. Individual males were followed for several years and also showed considerable syllable turnover between years. However, in this case, repertoire size was found to increase between years, the largest increase occurring between the first and second years. We obtained a significant positive correlation between repertoire size and age, suggesting that females choosing males with larger repertoires may gain indirect (genetic) benefits for their offspring, such as good genes for viability. Whilst these results reveal a more flexible picture of repertoire turnover than previously suspected, the relative stability of repertoire size within a season and the increase with age suggests that repertoire size remains a likely target for sexual selection by female choice.

Poly-Articulate

Poly-Articulate was a series of meditations around the paradoxes of articulation, considered in the heterogeneity of its material, visual, aural and conceptual aspects. Taking form through a collaborative working group of four artists/ designers/writers, the project used different technologies from the most ancient (the voice-box) to the most current (real-time rendering engines). With the utilisation of laser sensors crossing the gallery spaces, 20 digital monitors accompanied by vocal syllables would respond to the viewers? movement. Another piece of technology?a theramin installed below the sculpture of a trachea (inner ear)?mutated the vocal sounds upon its engagement along with a microphone suspended in one of the galleries. The visual and sound aspects of this project made it a compelling spatial experience.

An interactive CDRom accompanied with a text by Justin Clemens was published with this project.

Developmental stress affects the attractiveness of male song and female choice in the zebra finch (Taeniopygia guttata)

Developmental stress has recently been shown to have adverse effects upon adult male song structure in birds, which may well act as an honest signal of male quality to discriminating females. However, it still remains to be shown if females can discriminate between the songs of stressed and non-stressed males. Here we use a novel experimental design using an active choice paradigm to investigate preferences in captive female zebra finches (Taeniopygia guttata). Nine females were exposed to ten pairs of songs by previously stressed and non-stressed birds that had learned their song from the same tutor. Song pairs differed significantly in terms of song complexity, with songs of stressed males exhibiting lower numbers of syllables and fewer different syllables in a phrase. Song rate and peak frequency did not differ between stressed and non-stressed males. Females showed a significant preference for non-stressed songs in terms of directed perching activity and time spent on perches. Our results therefore indicate that developmental stress affects not only the structure of male song, but that such structural differences are biologically relevant to female mate choice decisions.

Response of the child with autism to preferred prosody during instruction

It has been found that incorporating preferences leads to improvements in target skills for children with autism. No studies have been found, however, that assess the preferences of children for prosody of teacher instruction. Prosody has been defined by fluency of speech, modification of pitch and stress of syllables. This research assessed the preference for, and effectiveness of, prosody of instruction by teachers of children with autism. The preferences of children with autism for monotone, conversational and enthusiastic voice prosodies were assessed. The children's teachers made recording of their own voice reading a story passage in the three selected prosodies. The children with autism were requested to listen to these recordings and select a preferred prosody over thirty three trials. Chi square analyses were conducted to determine the significant preferences from these trials. The selections of prosody of the children with autism were compared with the selections of typical children of the same age. Significant preferences were found for three children with autism and seven typical children. The three children with autism with significant preferences were observed in their classrooms. Teachers were cued with flashcards to use the different prosodies and the children's responses were recorded. An additional twenty instructions were recorded in which the teachers were not given a cue for voice prosody Chi square and Fisher's exact tests indicated that children's preferences did not influence their responses to prosody during classroom instruction. In other words the response in class was not related to prosody preference. Overall children were more likely to not respond to the monotone prosody. The enthusiastic and conversational prosodies were equally effective. Therefore it was concluded that continued and varied use of enthusiastic and conversational prosodies during classroom instruction would be effective for children with autism. It was recommended that future research focus on evaluating the effectiveness of variety of prosody for children with autism.