Microsatellites genotyping for common and lesser cuckoos

In a parasite species, the dispersal of individuals should be dependent on
host species to which they are specialized; thus, any sexual/individual
difference in host specificity may influence their dispersal patterns, and
hence, population genetic structures. However, such predictions remain
poorly verified in generalist avian brood parasites that is composed of
multiple lineages of host-specific races. Here, we show the dispersal
consequences inferred from spatial genetic structures and their
association with host specificity in brood parasitic common cuckoos
Cuculus canorus in which female-specific host race formation has been
widely accepted. Genetic sampling from adult cuckoos confirmed restricted
dispersal in both sexes and resultant genetic structures between
populations where different host species breed allopatrically, whereas it
was not the case between distant areas inhabited by the same host species.
Contrary to the female host race hypothesis, our results demonstrate that
male cuckoos may also have host specificity and disperse accordingly,
conclusively allowing us to hypothesize the formation of host race
including both sexes.