COPULATION BEHAVIOR IN THE LINNET CARDUELIS-CANNABINA AND THE INSEMINATION WINDOW HYPOTHESIS

Copulation behaviour in the Linnet was investigated by focal observati ons of breeding pairs near their nest sites. Of 287 observed male copu lation attempts only 37% resulted in cloacal contact. These successful copulation attempts were always preceded by female solicitation, indi cating that the outcome of copulations was under female control. Relat ive to the day of first egg (day 0), males attempted copulations from day -8 to +9 with a peak of 2.4 copulation attempts per hour al day -4 . However, females solicited copulations only from day -6 to +3, with a peak of 1.7 solicitations per hour on day -3. During the laying peri od male Linnets showed a significant peak in copulation attempts in th e second hour after egg laying. The importance of this peak in copulat ory behaviour after laying is discussed in relation to the inseminatio n window hypothesis.