From the Autumn 2024 concern of Dwelling Hen journal. Subscribe now.
Ornithologists and birders throughout the Northern Hemisphere have lengthy grappled with the query of what number of species of redpolls—small, streaky finches with neat pink caps—exist. In its 2024 guidelines replace, the American Ornithological Society offered a transparent reply: the three redpoll species beforehand acknowledged by the AOS—Widespread, Hoary, and Much lesser Redpoll (of Europe)—are actually a single species, identified merely as Redpoll.
This redpoll lump is the results of a 2023 proposal submitted to the AOS North American Guidelines Committee by Nicholas Mason, assistant professor at Louisiana State College; Erik Funk, postdoctoral fellow on the San Diego Zoo Wildlife Alliance; and Scott Taylor, affiliate professor on the College of Colorado. Mason and Taylor had been researchers on the Cornell Lab of Ornithology in 2015 after they accomplished DNA analyses that discovered no genetic variations between Widespread and Hoary Redpolls. Primarily based on these outcomes, revealed within the journal Molecular Ecology, they proposed lumping the 2 species in 2017. The committee declined, nonetheless, as a result of they mentioned the underlying analysis couldn’t totally clarify how the bigger, paler, shorter-billed Hoary Redpoll might look so completely different than a Widespread.
In 2021, Funk—then a PhD scholar in Taylor’s lab on the College of Colorado—discovered the reply. Utilizing whole-genome information, Funk discovered {that a} chromosomal inversion, also referred to as a “supergene,” explains the plumage variation inside redpolls [see “Of Inversions and Supergenes,” Spring 2022].
Whereas some birders may mourn the lack of one or two species from their private life lists, Taylor hopes the birding neighborhood will appreciate the fascinating new story of the pinkballot supergene discovery. “This truly makes redpolls much more fascinating to me,” he says. “You continue to have morphological [physical] variation despite the fact that you’ve gotten widespread gene circulate.”
Different highlights from this yr’s guidelines replace embody the splitting of the cosmopolitan Barn Owl into three species (American Barn Owl is the brand new identify for birds discovered within the Americas) and the splitting of Home Wren into two widespread species—Northern Home Wren and Southern Home Wren—and 5 Caribbean endemic species: Cozumel, Kalinago, St. Lucia, St. Vincent, and Grenada Wrens. See a full rundown of the 2024 AOS Guidelines adjustments.