Combinatory sound object play in cockatiels: a forerunner of music?
Résumé
An interest in producing sounds during play behaviour might be a forerunner for music. Thus, we explored object play behaviour involving sounds in cockatiels (Nymphicus hollandicus). We provided them with several objects producing sounds and recorded sound production, spontaneous warbles and drumming during breeding, pre-and post-breeding. Birds manipulated the objects in a playful way. They manipulated them less during breeding than during pre-and post-breeding, but the proportion of manipulations producing sounds were higher during post-breeding and breeding than during pre-breeding. Males manipulated the objects more frequently and produced more sounds than females. Youngsters manipulated the objects more than adults. One bird repeatedly put a bell on a xylophone; we discuss several possible explanations for the behaviour, including tool use. Only males warbled and drummed, and during breeding only. Our results suggest an enriching effect of the objects on the birds. Many aspects of musicality remain to be studied.