Christopher J. Clark, associate professor à l'Université de Californie

Christopher J. Clark nous présentera une partie de ses recherches sur la communication acoustique et les sons produits (ou pas) lors du vol chez certains animaux, dans une conférence intitulée « Animal Aeroacoustics: singing hummingbird feathers and the quiet flight of owls »

Résumé : Much as ordinary walking intrinsically produces footsteps, wings produce sound when an animal flies. Although in many birds these sounds are adventitious (with no communication function), flying animals have converted locomotion-induced sounds into communication signals dozens of times in birds and insects, but apparently rarely in bats. One curious pattern are birds like Costa's hummingbird, which produce both vocal song and non-vocal sounds with the tail during a dive. The song and the dive sound sound similar, despite physically different origins. Although why Costa's makes two similar sounds remains elusive, we conducted experiments which reveal much about how these sounds are similar. We show that, like songbirds, hummingbird song is socially learned; and the physics of the dive affects the dive-sound. Then I will consider what happens when locomotion-induced sounds are disadvantageous, which selects for quiet flight. Quiet flight has convergently evolved in certain raptors such as owls, and nocturnal birds such as nightbirds. Of all owls, Great Gray Owl has the most extreme wing features to suppress flight sounds, and is a snow-hunting specialist. I empirically measured how snow both refracts and attenuations sound, such that the best hunting strategy is to listen for prey from directly overhead.  

Si vous ne pouvez venir physiquement, vous pouvez vous connecter en suivant ce lien Zoom :

https://cnrs.zoom.us/j/99228706687?pwd=rBOYAINbvkhP4ablw4QcEcCXm2Nghd.1

Ce séminaire sera le dernier de l’année universitaire, nous cherchons des intervenants pour Septembre-Octobre 2024, pour des séminaires de 35-50 minutes le mardi de 12h30 à 13h30.

Pour la validation en tant que module de l'école doctorale, contactez-nous.

Les séminaires passés enregistrés sont visionnables sur la chaine Youtube de l’ISYEB : 

https://www.youtube.com/channel/UCzeFk4v_JcyK-N-H-1U19Bg

Bonne journée,

L’équipe des séminaires ISYEB