From the Autumn 2023 subject of Dwelling Chook journal. Subscribe now.
The American Ornithological Society launched its 2023 North American chook guidelines complement in July, and the replace to the ornithological community’s official record of acknowledged species has a decidedly retro really feel to it.
A headliner of the brand new replace is the splitting of Northern Goshawk into two species—American Goshawk and Eurasian Goshawk. The cut up follows the advice of George Sangster, a researcher on the Naturalis Biodiversity Heart within the Netherlands, who documented genetic and vocal differences amongst goshawks in North America and Eurasia. “American Goshawk” represents the return of a species identify that was beforehand acknowledged from the Eighties to the mid-Twentieth century.
The newest guidelines complement additionally turned again the clock on a yellow-olive Empidonax flycatcher, by lumping Pacific-slope Flycatcher and Cordilleran Flycatcher right into a single species known as Western Flycatcher. The lumping reverses an AOS North American Guidelines Committee resolution in 1989 that cut up the Western Flycatcher.
Colorado-based researcher W. Alexander Hopping (a current Cornell University graduate) and Ethan Linck, assistant professor at Montana State College, carried out the analysis that made the case for lumping the Western Flycatcher. They discovered that the place each types happen in southwestern Canada and the northwestern U.S., there aren’t any constant bodily, vocal, or genetic variations.
Shawn Billerman, a Cornell Lab of Ornithology scientist who studies the method of speciation amongst birds, is a member of the AOS verifyrecord committee that reviewed the flycatcher lumping proposal. He says that within the expansive space the place the previous Pacific-slope and Cordilleran Flycatchers overlap, “it’s unattainable to inform them aside as a result of the birds there are actually intermediate between the types. You solely have hybrids”—which suggests there’s proof of in depth interbreeding.
A number of Caribbean chook species splits spherical out this yr’s guidelines supplement highlights, together with newly recognized endemics for Cuba (Cuban Nightjar, Cuban Palm-Crow, and Cuban Bullfinch), Hispaniola (Hispaniolan Nightjar, Hispaniolan Palm-Crow, and Hispaniolan Euphonia), Puerto Rico (Puerto Rican Euphonia), and Grand Cayman (Grand Cayman Bullfinch).