Dusky Warbler (Phylloscopus fuscatus) Science Article 2
The fertility announcement hypothesis states that males sing most intensively during theperiod of female fertility in order to assure their paternity, as females would prefer to sexuallymate with males singing at a high rate. The dusky warbler (Phylloscopus fuscatus) is one ofthe species in which singing intensity clearly peaks when females are fertile. As a test of thefertility announcement hypothesis, we study why males of this species sing so much afterpairing.
WOLFGANG FORSTMEIER and THORSTEN J.S. BALSBY, Behaviour 139, 89-111