Dietmar Todt

Learn More
This study on common marmosets Callithrix jacchus is the first to examine noise-dependent mechanisms of vocal plasticity in a New World monkey. Since acoustic communication can be considerably impaired by environmental noise, some animals have evolved adaptations to counteract its masking effects. The studied marmosets increased the sound level of their(More)
Position preferences of well-fed and food-deprived juvenile roach were investigated in schools of 2 and 4 fish in the laboratory. Food-deprived fish appeared significantly more often in the front position than their well-fed conspecifics. For fish at the same hunger level, individuals at the front of the school had the highest feeding rate. These results(More)
The temporal patterning of vocal interactions between territorial nightingales (Luscinia megarhynchos B). was investigated during nocturnal dyadic singing. We distinguished three forms of temporal performance roles (Table 1; Fig. 3): inserter (preferred song start 0.5–1.0 s after offset of a neighbour's song), overlapper (preferred song start 0.5–1.0 s(More)
The relationship was studied between song-post distances and the extent of vocal repertoire sharing in 34 territorial nightingales settling in six homogeneously structured habitats. Repertoires were compared on the basis of shared song types and distances were measured between nocturnal song posts of first-order and higher-order neighbours. Our results(More)
Field studies in various species ofMacaca (Cercopithecidae) provided evidence for specific visual displays that typically accompany playful interactions. The aim of our study was to examine whether and when playing individuals would use auditory displays, i.e. vocalizations that often occur during social play as well. The study was conducted on a population(More)
To examine the properties of avian song memorization, handraised nightingales (Lusdnia megarhynchos) were exposed to three strings composed of 21 or 12 different song types (Fig. 1) which they heard only during the tutoring programs. The analysis of the birds' singing performed several months later revealed a kind of song memorization and production which,(More)
We thank F. Abbet, M. Ackermann, M. F. Blanc, D. and F. CMttelain for careful technical assistance, B. Maichel for typing the manuscript, L. Slomkowski for photography, and the University of Geneva for supporting part of this work. B. L. was awarded with a fellowship from the Italian Government. J. M. was supported by funds from the University of Geneva. K.(More)
Many songbirds develop remarkably large vocal repertoires, and this has prompted questions about how birds are able to successfully learn and use the often enormous amounts of information encoded in their various signal patterns. We have studied these questions in nightingales (Luscinia megarhynchos), a species that performs more than 200 different types of(More)
due to species differences. The flattened maximum we found in the yellow to orange-red region could be due to cooperation of a variety of sensitivity peaks in this waveband. Thus, for example, one single cone type could be combined with a variety of oil droplets which differ in their cut-off wavelength [6, 71. The hypothesis that color vision in birds is(More)
Exposure to laughter has striking effects on human listeners and may facilitate positive emotional and behavioural responses. The acoustic signal pattern of laughter vocalisations is particularly suitable to elicit these reactions. However, little is known about factors that lead to differences in reactions of listeners. The acoustic quality of laughter,(More)