TY - JOUR
T1 - Eider females form non-kin brood-rearing coalitions
AU - Öst, Markus
AU - Vitikainen, Emma
AU - Waldeck, Peter
AU - Sundström, Liselotte
AU - Lindström, Kai
AU - Hollmén, Tuula
AU - Franson, J Christian
AU - Kilpi, Mikael
PY - 2005/10
Y1 - 2005/10
N2 - Kin selection is a powerful tool for understanding cooperation among individuals, yet its role as the sole explanation of cooperative societies has recently been challenged on empirical grounds. These studies suggest that direct benefits of cooperation are often overlooked, and that partner choice may be a widespread mechanism of cooperation. Female eider ducks (Somateria mollissima) may rear broods alone, or they may pool their broods and share brood-rearing. Females are philopatric, and it has been suggested that colonies may largely consist of related females, which could promote interactions among relatives. Alternatively, shared brood care could be random with respect to relatedness, either because brood amalgamations are accidental and nonadaptive, or through group augmentation, assuming that the fitness of all group members increases with group size. We tested these alternatives by measuring the relatedness of co-tending eider females in enduring coalitions with microsatellite markers. Females formed enduring brood-rearing coalitions with each other at random with respect to relatedness. However, based on previous data, partner choice is nonrandom and dependent on female body condition. We discuss potential mechanisms underlying eider communal brood-rearing decisions, which may be driven by the specific ecological conditions under which sociality has evolved in this species.
AB - Kin selection is a powerful tool for understanding cooperation among individuals, yet its role as the sole explanation of cooperative societies has recently been challenged on empirical grounds. These studies suggest that direct benefits of cooperation are often overlooked, and that partner choice may be a widespread mechanism of cooperation. Female eider ducks (Somateria mollissima) may rear broods alone, or they may pool their broods and share brood-rearing. Females are philopatric, and it has been suggested that colonies may largely consist of related females, which could promote interactions among relatives. Alternatively, shared brood care could be random with respect to relatedness, either because brood amalgamations are accidental and nonadaptive, or through group augmentation, assuming that the fitness of all group members increases with group size. We tested these alternatives by measuring the relatedness of co-tending eider females in enduring coalitions with microsatellite markers. Females formed enduring brood-rearing coalitions with each other at random with respect to relatedness. However, based on previous data, partner choice is nonrandom and dependent on female body condition. We discuss potential mechanisms underlying eider communal brood-rearing decisions, which may be driven by the specific ecological conditions under which sociality has evolved in this species.
KW - Animals
KW - Ducks/genetics
KW - Female
KW - Finland
KW - Gene Frequency
KW - Genotype
KW - Maternal Behavior
KW - Microsatellite Repeats/genetics
KW - Nesting Behavior
KW - Sequence Analysis, DNA
U2 - 10.1111/j.1365-294X.2005.02694.x
DO - 10.1111/j.1365-294X.2005.02694.x
M3 - Article
C2 - 16202104
SN - 0962-1083
VL - 14
SP - 3903
EP - 3908
JO - Molecular Ecology
JF - Molecular Ecology
IS - 12
ER -