DNA barcoding uncovers likely new species of birds and bats

In the first effort to ever “barcode” species on a continental scale, scientists have completed a pilot study of U.S. and Canadian birds that suggests that 15 new genetically distant species have been overlooked in centuries of bird studies. The research validates DNA “barcoding” as an efficient means of identifying species based on just a tiny sample of biological material, and it has implications for environmental research as well as for reducing contamination in our food supply and preventing collisions between aircraft and birds.

Revealing the results of two tests of unprecedented scale, scientists from Rockefeller University and the University of Guelph, along with colleagues at the Smithsonian Institution, the Canadian Wildlife Service and the Royal Ontario Museum, report they have genetically identified 15 likely new bird species in the U.S. and Canada, nearly indistinguishable to human eyes and ears, as well as six likely new species of bat in Guyana. They also say 14 pairs of North American bird species with separate identities are in fact DNA twins.

The DNA portrait of 643 bird species, from the Arctic tundra to the temperate woodlands to the Florida Keys, represents 93 percent of 690 known breeding species in the U.S. and Canada. DNA from the birds was obtained from “voucher” specimens in museums, augmented by samples sent in by people who band animals for study in the wild. Work continues to collect DNA of the remaining 47 listed North American species, as well as several more considered extinct, with the goal of completing an all-bird DNA inventory by 2011.

The researchers say that at a global scale, DNA barcoding may help distinguish 500 to 1,000 additional bird species. “Some pairs of listed species now shown to be DNA twins – most famously Northwestern and American crows, which have different ranges – may be relatively young species and prove different over time,” says Mark Stoeckle, an adjunct faculty member in Rockefeller University’s Program for the Human Environment.

The bat study was designed to give barcoding the toughest test possible. “The bats of Guyana have been the subject of intensive taxonomic work and yet we found we could recognize 100 percent of the surveyed species and discovered a number of overlooked bats,” says Paul Hebert, professor of integrative biology at the University of Guelph.

When fully established, the barcode database will help quickly identify undesirable animal or plant material in food and detect regulated species in the marketplace. It may also help reconstruct food cycles by identifying fragments in stomachs and assist plant science by identifying roots sampled from soil layers. A standardized library of barcodes will enable more people to identify species – whether abundant or rare, native or invasive – and will be an important resource in efforts to preserve biodiversity both locally and globally.

The work could also lead to hand-held DNA devices for instant species identification, for instances in which it is not possible or convenient to identify species based on shape, sound or color.

Molecular Ecology Notes Online (January 18, 2007)
Molecular Ecology Notes Online (January 12, 2007)
www.barcodinglife.org