IS THE BLACK ROBIN IN GENETIC PERIL

In 1980 the entire black robin species Petroica traversi comprised onl y five birds, and the current population of approximate to 200 individ uals is known to be derived from a single breeding pair. We show here that levels of minisatellite DNA variation in the black robin are amon g the lowest reported for any avian species in the wild. Surprisingly, similarly bottlenecked control populations of a closely related speci es (P. australis australis) exhibit significantly higher levels of gen etic variation. This suggests that the black robin's persistence in a single small population for the last 100 years, rather than the recent bottleneck itself, accounts for the low genetic variation observed. D espite apparent genetic impoverishment, survival and reproductive perf ormance indicate that the black robin is viable under existing conditi ons. This example illustrates that significant levels of genetic varia tion are not a necessary prerequisite for endangered species' survival .