Is there age assortative mating in the European White Stork?

Data oil age correlation between members of breeding pairs of the European White Stork (Ciconia ciconia) were collected during a long-term study (20 years) of this species in western France. Data From 43 pairs of known age indicated significant age correlation between mates. We tested if the age correlation could be explained by nonrandom mate selection with respect to age or experience or by factors linked to the life-history traits of that species. However, when mate changes occurred, White Storks did not choose their new mate according to experience. Consequently, the correlation between ages of mates is not achieved by nonrandom mate selection with respect to age or experience. Possible causes leading to the observed age correlation are discussed.