Behaviour, Volume 141, Number 3 (2004) http://dandini.ingentaselect.com/vl=751105/cl=30/nw=1/rpsv/cw/brill/00057959/v141n3/contp1-1.htm
(Abstracts below) Ligout; S, F Sebe & RH Porter (2004) Vocal discrimination of kin and non-kin agemates among lambs. Behaviour 141: 355-369. Kipper, S, R Mundry, H Hultsch & D Todt (2004) Long-term persistence of song performance rules in nightingales (Luscinia megarhynchos): a longitudinal field study on repertoire size and composition. Behaviour 141: 371-390. ---------------------- Abstracts Ligout; S, F Sebe & RH Porter (2004) Vocal discrimination of kin and non-kin agemates among lambs. Behaviour 141: 355-369. Abstract: Playback experiments were conducted with 4 week old Ile-de-France lambs (Ovis aries) to assess the role of auditory cues in social discrimination. After being habituated to the test enclosure, lambs were individually exposed to bleats from two stimulus individuals. Twin lambs were tested with recorded bleats of their sibling versus an unfamiliar agemate and single lambs with bleats of a familiar agemate versus an unfamiliar lamb. Lambs responded more frequently to the bleats of their sibling (for twin lambs) or of a familiar agemate (for single lambs) than to those of an unfamiliar lamb. Such discriminative responses to the bleats of familiar twins and non-kin lambs suggest that vocalizations may be a sufficient basis for social recognition. Acoustic analyses of the playback bleats revealed significant differences between the signals from the different stimulus lambs and suggest that fundamental frequency may be an important parameter of lambs' individual vocal signatures. Kipper, S, R Mundry, H Hultsch & D Todt (2004) Long-term persistence of song performance rules in nightingales (Luscinia megarhynchos): a longitudinal field study on repertoire size and composition. Behaviour 141: 371-390. Abstract: Common nightingales (Luscinia megarhynchos) are among those bird species that possess an extremely large repertoire and perform it in a versatile singing style. Thereby, repertoire size, composition, and performance differs considerably among individuals. In this longitudinal field study, we investigated the long-term stability of these differences in the song characteristics of free-ranging nightingales. We determined the repertoire characteristics for nine adult male individuals in two successive years (three of these individuals were investigated over the course of three years) and compared these to similar measurements obtained from comparisons of song samples of different birds. Comparisons revealed remarkable differences among males, but we did not find systematic differences in the song performance of birds in successive years. Instead, song characteristics were remarkably stable within successive years. The long-term persistence of individual song characteristics suggests that they are not related to dynamically changing individual attributes, but may reflect long-term storage of information during song acquisition as juveniles. In addition, we found that the repertoire performance of adult nightingales allows fine-tuned vocal interactions among several neighbouring males.
