TY - JOUR

T1 - Sibling competition and the evolution of growth rates in birds.

AU - Royle, Nick J.

AU - Hartley, Ian R.

AU - Owens, I. P. F.

AU - Parker, G. A.

PY - 1999/5/7

Y1 - 1999/5/7

N2 - Variation among bird species in growth rates is traditionally attributed to differences in energy availability and developmental mode. However, the extent and form of competition among siblings for limited food resources may also be an important determinant. Kin-selection-based models of intrabrood competition suggest that nestling growth rates should be highest in those species in which siblings are likely to be less genetically related to one another (half-sibs rather than full-sibs). We test this novel prediction using the frequency of multiple paternity as an index of average sib relatedness within broods. As predicted, we find a significant positive association between the rate of multiple paternity within broods and nestling growth rates. Furthermore, this holds true when we control for the effects of variation in other factors that may be associated with variation in growth rate, such as body size, brood size, mating system and the form of parental care. We suggest, therefore, that variation in growth rate among bird species is not simply dependent on proximate ecological and developmental factors but is also strongly influenced by interactions, over an evolutionary time-scale, among kin.

AB - Variation among bird species in growth rates is traditionally attributed to differences in energy availability and developmental mode. However, the extent and form of competition among siblings for limited food resources may also be an important determinant. Kin-selection-based models of intrabrood competition suggest that nestling growth rates should be highest in those species in which siblings are likely to be less genetically related to one another (half-sibs rather than full-sibs). We test this novel prediction using the frequency of multiple paternity as an index of average sib relatedness within broods. As predicted, we find a significant positive association between the rate of multiple paternity within broods and nestling growth rates. Furthermore, this holds true when we control for the effects of variation in other factors that may be associated with variation in growth rate, such as body size, brood size, mating system and the form of parental care. We suggest, therefore, that variation in growth rate among bird species is not simply dependent on proximate ecological and developmental factors but is also strongly influenced by interactions, over an evolutionary time-scale, among kin.

U2 - 10.1098/rspb.1999.0725

DO - 10.1098/rspb.1999.0725

M3 - Journal article

VL - 266

SP - 923

EP - 932

JO - Proceedings of the Royal Society B: Biological Sciences

JF - Proceedings of the Royal Society B: Biological Sciences

SN - 0962-8452

IS - 1422

ER -