Integrating genetic and photo-identification data to assess reproductive success in the North Atlantic right whale (Eubalaena glacialis)

The North Atlantic right whale is the most endangered large whale species, with only ∼300 individuals remaining. Despite over 70 years of international protection and 20 years of research and conservation actions there have been no signs of recovery. This lack of recovery is partially due to the reduced reproductive performance of this species, which is three times lower than expected. To gain a better understanding of reproduction, and the reproductive problem, over 20 years of photo-identification data were combined with high-resolution genetic data for ∼75% of all identified individuals in this species.; Methods were developed to rapidly and reliably genotype samples at 35 microsatellite loci. Comparison of individual identification data from the photo-identification and genetic databases resulted in estimated error rates of 0.64% and 0.96% for each technique, respectively. This represents one of the first cases where both of these methods have been validated for a single species, with the low error rates validating both techniques as reliable sources of individual-based data.; Parentage analyses suggest that males obtain their first fertilization at an older age than females, and identified a case where two calves were switched between mothers and remained with their 'adopted' mothers throughout their first year. The heterozygosity of offspring of known mating pairs is significantly higher than expected (p < 0.028), suggesting that genetic factors are influencing reproductive success and that only matings between genetically divergent individuals are successful. Genetic inference of individuals through parentage analysis indicated that the population size is significantly larger than has previously been estimated though photo-identification techniques alone (p < 0.005), with an estimate of 11--12% more individuals in the species than are currently accounted for based on photo-identification techniques. Combined, these data not only influence the understanding of the status of this species, but also the factors influencing reproductive success and species recovery.