Birds and barcodes
The All Birds Barcoding Initiative (ABBI), held its first meeting at Harvard University’s Museum of Comparative Zoology in September 2005, has a mighty ambitious goal: to collect DNA barcodes from each of the approximately 10,000 known species of birds. Even after several hundred years of work on identifying bird species, genetic surveys – including those using DNA barcoding – show that hundreds of avian species have yet to be fully described and understood. “Our barcode surveys reveal cases of deep [DNA] sequence divergence in some bird species, suggesting that the members of a species actually have not been interbreeding for a long time,” explains Paul Hebert, director of the Biodiversity Institute of Ontario. Detailed studies of birds such as the eastern meadowlark have revealed significant differences in the species’ physical characteristics and song patterns in various locations. In fact, there are two species: eastern and western medowlarks.

The ABBI aims to speed up the discovery of new species and provide a practical tool for specimen identification. To date, more than 17,000 specimens from almost 3,000 species have been barcoded. By depositing these records in Hebert’s Barcode of Life database, investigators are establishing an electronic library of avian DNA, reference specimens and other collection data. Conservation planners, ornithologists, ecologists, public health officials and interested amateurs will then be able to consult this database to easily confirm – from as little as a single feather – a given bird’s identity, regardless of its age, sex or plumage.

The ABBI is a testing ground for DNA barcoding, the larger initiative to catalogue all animal and plant life. As part of the ABBI, Environment Canada is supporting the development of a reference database for all North American bird species. Using samples in the Royal Ontario Museum and Environment Canada’s National Wildlife Research Centre tissue bank, along with U.S. sample sources, the project has produced DNA barcodes for more than 95 percent of recognized species on the continent.

Visit the ABBI website for more information.

Paul Christopher Webster

Charles Francis, manager of species abundance and distribution at Environment Canada, says the potential of Hebert’s work is significant. “DNA barcodes could be used to confirm the identities of birds or other animals involved in an enforcement case,” he explains. For example, officials could test any meat product, even a sausage (provided it has not been cooked), to find out what animals went into its making. Researchers have used barcodes to confirm the identities of birds so heavily covered in oil that their plumage patterns were obscured, he says. “They have also been used to identify blood smears and feathers stuck to aircraft that have hit birds, which can help with understanding the risks to both birds and planes, and avoiding them,” he adds.

Francis argues that DNA barcodes will help enforce international trade regulations under the Convention on International Trade in Endangered Species. “It is difficult for customs officers to have expertise in identifying all types of endangered species from throughout the world,” he points out. As long as the product they are inspecting contains a DNA sample, such as hair or skin or feather, DNA barcodes could quickly confirm its source.

The ability to read and quickly sequence DNA has transformed species scholarship and protection, Hebert says. “We can do forensics on life.” In a recently published study on eastern red bats, for instance, Hebert and a team of biologists from the University of Guelph and the University of Western Ontario used his techniques to identify fragments of prey animals in red bat guano, gaining insight into the bats’ food sources and the workings of the entire ecosystem.

Hebert believes, however, that it is in the field of biodiversity conservation that the Barcode of Life will yield the greatest advances. “Simply put, you can’t conserve something if you can’t recognize it,” he says. The database will enable scientists to trace the evolutionary patterns and cross-relationships of innumerable as yet unstudied species. A Quebec colleague of Hebert’s, for example, has used barcoding to examine fish parasites in a new way, and discovered that, for the most part, the parasites are highly specialized.

Hebert says that, through barcoding, conservation strategies will move beyond large, relatively easily monitored species such as whales, eagles and polar bears toward lesser known or currently unknown species of insects and biota that may be vitally important within their own ecologies and may offer valuable medicinal or other properties. Currently, vast numbers of species are in danger of disappearing without ever having been identified. In tackling this knowledge gap, the Barcode of Life project is already yielding rich results; new life forms have been discovered on every continent except Antarctica. “New species have been found just about everywhere we have looked and in every group: birds, fish, insects, crustaceans,” says Hebert. “We used barcoding to reveal that the commonest butterfly that one sees along roadsides in Central America is actually 10 different species whose adults happen to look much alike, but their larvae have different colour patterns and they feed on different plants.”

Indeed, projects like the Barcode of Life are helping scientists realize just how little we really know about bio-diversity. “As a consequence, conservation plans are largely a shot in the dark,” Hebert argues, because different species we cannot yet tell apart may require different strategies. To protect a species, Hebert warns, “you need to know where it sleeps at night. You need to know what it eats. You need to know it intimately. Every bit of knowledge is crucial.”