MALE AND FEMALE NEST ATTENDANCE DURING INCUBATION IN THE FACULTATIVELY POLYGYNOUS EUROPEAN STARLING

We examined parental roles in incubation with respect to mating status in the facultatively polygynous European starling Sturnus vulgaris. I n monogamous pairs, male and female nest attendance did not differ sig nificantly. In primary and secondary broods, male nest attendance was significantly lower than that of the female. Bigamous males assisted t heir second female in incubating only when the time interval between t he onset of incubation of the two females was less than five days. Pol ygynously mated females compensated for the loss of, or reduction in, male assistance by significantly increasing their own nest attendance. They took shorter foraging recesses and made significantly more reces ses per hour than monogamous females. Nevertheless, total nest attenda nce in polygynous broods (85%) still was significantly lower than that in monogamous broods (98%), indicating that polygynously mated female s cannot compensate fully. We found no significant difference in incub ation duration and hatching success between monogamous and polygynousl y mated females suggesting that the latter could maintain sufficient n est attendance for successful incubation. Future studies should concen trate on the effect of single-sex incubation on the condition and surv ival of female starlings.