DAWN CHORUS AND FEMALE BEHAVIOR IN THE WILLOW TIT PARUS-MONTANUS

We studied the effect of female behaviour on the dawn chorus of Willow Tits Parus montanus. Ten females were temporarily kept in their nest holes in order to delay their dawn emergence. Simultaneously, their ma tes' singing behaviour was measured. We compared the control dawn beha viour (during which the females emerged when they wanted) with that du ring the experimental delay. The dawn song by the males lasted longer when the females' emergences were delayed. Our results show that the d uration of the dawn chorus is directly related to the female's behavio ur. We suggest that at least one function of the dawn song is intrapai r signalling, which is often linked to sperm competition.