AGE-ASSORTATIVE PAIRING IN THE GREATER FLAMINGO PHOENICOPTERUS-RUBER ROSEUS

Among long-lived bird species, the partners of breeding pairs are ofte n of similar age. This pattern is largely influenced by little variati on in the age at first breeding, linked with high survival rate and pr olonged pair bonds. Contrary to other long-lived colonial species, Gre ater Flamingos Phoenicopterus ruber roseus do not show mate fidelity o ver consecutive breeding seasons. We studied pairing patterns of Great er Flamingos breeding in the Camargue, southern France, between Decemb er 1989 and March 1992. In each year, significant correlations were ob served between the ages of the male and the female in a pair. The patt ern of age-assortative mating was confirmed independently in each year by comparing the frequency distribution of age differences within pai rs with the theoretical distribution derived from the age distribution of paired birds of known age in the population, assuming random pairi ng with respect to age. There was no evidence of a differential time o f return each year to the colony with age. Analysis of display behavio ur suggested that age-assortative mating in the Greater Flamingo resul ts from a directional pairing preference for older and more experience d individuals. The present study provides direct evidence that age-ass ortative mating can occur independently of mate fidelity.