DNA fingerprinting of captive breeding pairs of lesser white-fronted geese (Anser erythropus) with unknown pedigrees.

For a number of decades, the lesser white-fronted goose (Anser erythropus) has been almost-absent from the Fennoscandian fauna and has a current population size of only about 60 breeding pairs, with fewer than 10 pairs in Sweden. During the period 1981-1991 more than 200 young have been reintroduced in northern Sweden. However, the origin and possible relatedness of lesser white-fronted individuals were unknown when the breeding program started. We have used DNA fingerprinting to assess the similarity of 18 individuals, i.e., the entire captive population used for breeding in 1991 and about 60% of the captive population used in 1981-1991. Minisatellite probe 33.15 provided an index for an average similarity of 0.39 between the mates of the 12 breeding pairs used for producing offspring for reintroduction. This is a higher similarity than in natural populations of birds in general but lower than in populations that have passed through serious population bottlenecks. Individuals originating from different breeders are more dissimilar than those from the same breeder. However, the close relationships (similarity, 0.5-0.6) found in a group of five individuals from different breeders show that selecting individuals from different breeding groups is not sufficient to prevent mating between closely related individuals.