Citation: Pichl, H., K. E. Erikstad, P. Fauchald and T. Tveraa (1997) Manipulating parental effort: costs of reproduction in the kittiwake Rissa tridactyla. – Poster presented at the VIth Biennial Congress of the European Society for Evolutionary Biology in Arnhem.
Abstract: The costs of reproduction in kittiwakes were studied from 1995–1996 on Horn°ya, northern Norway, by enlarging and decreasing brood sizes of two chicks by one at day 3 post-hatch. Parents with enlarged broods produced more fledged chicks than parents with control and reduced brood size, but the body mass of chicks from enlarged broods were lower than that of chicks from control and reduced nest. Three weeks post-hatch, the body masses of females, but not males, that reared enlarged clutches were lower than among those rearing control and reduced broods. The return-rates of females rearing enlarged broods were lower than among those rearing control and reduced broods, but this trend was not statistically significant. These results differ somewhat from a previous study of kittiwakes in the same study area which showed that the parents were not able to raise an additional chick, and, moreover, that females rearing enlarged clutches suffered a reduced survival. The differences between these two studies will be discussed in context of adaptations to a stochastic environment.
Related publications: This poster contained preliminary results that were elaborated in my master thesis.