Word's Top 100 Most Unique and Endangered Birds Defined in New Study
A new attempt to create a hierarchy of the most threatened birds relies on an idea that measures "evolutionary distinctiveness," and researchers have used it to list the world's 100 most unique and endangered birds.
Not all species are equal, the researchers contend, and evolutionary distinctiveness is a measure of how genetically or evolutionarily unique a species is. By using this as a measure, conservationists can focus their attention on saving species whose loss would serve as the greatest blow to species diversity and the history of evolution.
The scientists published their research in the journal Current Biology.
"Not all species are evolutionarily equal - some have few close relatives that share their DNA," said study co-author Gavin Thomas of the University of Sheffield. "These species are irreplaceable. If they are driven to extinction, millions of years or evolutionary history goes with them."
Some bird species, such as the Oilbird, have tens of millions of years of evolutionary history behind them, while other species only came into existence relatively recently. Many of these early-evolving birds do not have close living relatives, and should be given conservation priority, the researchers said.
"To date, conservation has emphasized the number of species, treating all species as equal," said lead study author Walter Jetz, a Yale University evolutionary biologist. "But not all species are equal in their genetic or geographic rarity. We provide a framework for how such species information could be used for prioritizing conservation."
There are nearly 10,000 living species of birds, and around 600 of them are at risk of becoming extinct as a result of human development pressures and changes to their environment.
Jetz said that conserving some of these endangered species is challenging because many of them live far away from areas that already receive environmental protection.
By applying evolutionarily distinctiveness ratings to the geographic ranges of all 9,993 living bird species, the researchers documented areas where maximum conservation of bird diversity could be achieved with minimal investment.
Notable target areas include regions of Australia, Indonesia, Brazil, and Madagascar, the researchers reported.
"In addition to targeted conservation, better monitoring of species' changing distributions is vital, and geographical conservation priorities can be effectively adjusted to better conserve the tree of life and the many important functions it provides," Jetz said. Jetz also leads the Map of Life project, which maps avian species distribution and range maps for evolutionarily distinct species.
The researchers report the top 10 most unique and endangered birds are: