DNA reveals long-distance partial migratory behavior in a cryptic owl lineage

Background The Brown Hawk Owl complex is said to consist of three species, the Brown Boobook (Ninox scutulata), the Chocolate Boobook (Ninox randi) and the Northern Boobook (Ninox japonica), which includes the nominate migratory lineage Ninox japonica japonica and a mitochondrially distinct lineage of taxonomically uncertain status that has been recorded year-round at least in Taiwan. Overlap in ranges during migration and morphological similarity have led to difficulties in distinguishing the Brown Boobook from the Northern Boobook.

Methods PCR of cytochrome-b and Sanger sequencing of Ninox samples from Singapore and Brunei were used to determine sample identity.

Results Two out of four Singaporean samples and the Brunei sample were identified as Northern Boobooks. This is the first official record of this species in Singapore and represents a considerable range extension for the species. Further, the samples belong to the mitochondrially distinct lineage previously characterized in resident Taiwanese populations rather than to the well-known nominate migratory lineage.

Conclusions Our data show that the mitochondrial signature previously documented in resident Taiwanese populations of the Northern Boobook extends to migratory populations. This cryptic lineage may be more widespread in its breeding quarters, extending to the Chinese and Russian mainland, in which case the name florensis would apply to it. Further genetic and bioacoustic investigation is required to resolve the taxonomic status of this lineage.