The Kentish-Snowy Plover, a small shorebird found in the US and Europe, is suffering from an identity crisis after scientists at the Universities of Bath and Sheffield found genetic evidence that the populations are, in fact, separate species.
Historically, biologists have classified the Kentish Plover, found in Europe, and its look-a-like, the Snowy Plover, from the US, as being different varieties from the same species due to their similar looks.
Whilst their true identity has been long debated by biologists, this is the first time that scientists have found proof that the birds actually belong to different species.
These new findings could prove important in the conservation of the Snowy Plovers, which are listed as threatened.
The scientists from the Universities of Bath and Sheffield analysed the DNA of 166 birds from two different American populations of Snowy Plover, four Eurasian populations of Kentish Plover, and one African population of a closely related species, the White-fronted Plover.
They found that the European birds were more similar to their African cousins than to their relatives in America, indicating that the bird population split and colonised America, where they became Snowy Plovers, before splitting again to produce Kentish and White-fronted plovers.
Dr Clemens Küpper, from the University of Bath's Department of Biology & Biochemistry, explained: "Scientists have suspected for some time that these birds are from different species.
"Although they look similar, for them to have stayed as a single species they would have had to be able to breed with each other, but this wasn't possible because they were separated by thousands of miles of water!
"For the first time we've shown that these birds have been separated for a long time and evolved in different directions."
Professor of Molecular Ecology Terence Burke, from the Department of Animal and Plant Sciences at the University of Sheffield, said: "It will hopefully make a huge difference. Usually few people are concerned if a local population of birds vanishes. However, when an entire species is threatened, conservation efforts will be stepped up."
The researchers hope next to map exactly how the Snowy Plovers colonised America.
Meanwhile, birdwatchers will be pleased to know that there are now two types of bird to look for!
The study, published in the October issue of ornithologists' journal The Auk, was funded by the Natural Environment Research Council, the Biotechnology & Biological Sciences Research Council and the National Geographic Society. The researchers also received funding from the Leverhulme Trust and European Community.