Discovery of a new breeding population of the Vulnerable Swinhoe’s Rail Coturnicops exquisitus confirmed by genetic analysis

Abstract

SummaryThe ‘Vulnerable’ Swinhoe’s Rail Coturnicops exquisitus is believed to occur in only two regions in Russia’s Far East and China’s Heilongjiang province, separated by more than 1,000 km. Recent observations suggest that the Amur region, situated between the two known populations, might be inhabited by this secretive species as well. As the species is rather similar in appearance and field characteristics to its Nearctic sister taxon, the Yellow Rail C. noveboracensis, and almost all field records relate to flushed individuals in flight, we aimed to complement the field observations by genetic evidence. Samples were obtained from four individuals and one eggshell and their mitochondrial cytochrome b genes were amplified and sequenced. The genetic analyses unequivocally confirmed that swab samples and eggshell were attributable to Swinhoe’s Rail, thus constituting the first known breeding record of this species for 110 years. It is therefore likely that the individuals observed in the field also belonged to this species. It seems possible that Swinhoe’s Rail is more widely distributed in the Amur region and was overlooked in the past, possibly due to a misleading description of its calls in the literature.