Soft song during aggressive interactions: seasonal changes and endocrine correlates in song sparrows.

摘要: Abstract It is well known that songbirds produce high amplitude songs (“broadcast songs”). Songbirds also low (“soft songs”) during courtship or territorial aggression in the breeding season. Soft are important social signals but have been studied far less than broadcast songs. To date, no studies examined seasonal changes soft song its endocrine regulation. Here, male sparrows, we a simulated intrusion season and non-breeding We measured plasma testosterone dehydroepiandrosterone (DHEA) levels subjects immediately after aggressive encounter. The total number of produced (broadcast + soft songs) did not vary between seasons. However, there was dramatic increase percentage Further, negatively correlated with There were differences acoustic structure two major elements song, trills buzzes. minimum frequency lower season, element repetition rate buzzes our knowledge, this first study to (1) examine outside (2) identify correlates songs, which songbirds.