Redpolls United! Highlights from the 2024 AOS Checklist Update

From the Autumn 2024 issue of Dwelling Chicken 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 purple caps—exist. In its 2024 guidelines replace, the American Ornithological So­ciety supplied a transparent reply: the three redpoll species beforehand acknowledged by the AOS—Frequent, Hoary, and Much less­er Redpoll (of Europe)—are actually a single species, recognized 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 Frequent and Hoary Redpolls. Primarily based on these outcomes, printed within the journal Molecular Ecology, they proposed lumping the 2 species in 2017. The committee declined, nonetheless, as a result of they stated the underlying analysis couldn’t totally clarify how the bigger, paler, shorter-billed Hoary Redpoll might look so completely different than a Frequent.

In 2021, Funk—then a PhD pupil in Taylor’s lab on the College of Colorado—discovered the reply. Utilizing whole-genome knowledge, 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 would possibly mourn the lack of one or two species from their private life lists, Taylor hopes the birding group will appreci­ate the attention-grabbing new story of the purple­ballot supergene discovery. “This really makes redpolls much more fascinating to me,” he says. “You continue to have morpho­logical [physical] variation despite the fact that you’ve got widespread gene stream.”

Different highlights from this yr’s guidelines replace embrace the splitting of the cosmopolitan Barn Owl into three species (American Barn Owl is the brand new title 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 Checklist changes.