Wednesday, April 5, 2017

2017 AOS (AOU) Proposed Lumps and Splits


Western Willets (above) have long been considered to be distinct in a number of ways from Eastern Willet, and can be told apart in the field with some practice. Will this be the year of the great Willet split?

The proposals are in...there are an obscene number of splits and lumps proposed for birds under the American Ornithological Society's purview this year. There is the potential for a lot of huge shakeups...of course, who knows how many of these will actually become Bird Law? Maybe none at all! In any case, we can expect a lot of butthurt birders after news of these splits and lumps (or lack thereof) is released. Perhaps these decisions will all be warranted, perhaps not, but regardless of what happens there are a lot of sweaty palms out there right now, and almost too many splits/lumps to keep track of. For your sake, beloved readers, I have gleaned all the splits and lumps from the three rounds of proposals that are out. No rearranging of families or genera to sort through, no simple name changes, just the meat and potatoes - the splits and lumps.

Split Willet into Eastern Willet and Western Willet.


Lump Thayer's (above) and Iceland Gull. Thayer's Gull would become a subspecies of Iceland, and the kumlieni subspecies would lose its status and be considered a hybrid swarm. Birders are coming out of the woodwork to make their opinions known about the Thiceland Gull proposal, some of which don't seem to be informed by actual facts. This one, as predicted, really struck a nerve. 

Recognize Northern Harrier and Hen Harrier as different species.

Split Magnificent Hummingbird into two species, Rivoli's and Admirable Hummingbirds (northern and southern populations).

Split Emerald Toucanet into a bunch of different species.

Split Guatemalan Flicker from Northern Flicker.

Recognize Northern Shrike and Great Gray Shrike as different species.


Split Least Vireo (above) from Bell's Vireo. Drab western birds like this one would become Least Vireo, the more colorful eastern birds would remain known as Bell's Vireo. Simple.

Split Grayson's Robin from Rufous-backed Robin.

Split Nearctic Creeper from Brown Creeper; or perhaps split Brown Creeper into Nearctic Creeper and Neotropical Creeper.

Split Nashville Warbler into two species, Rusty-capped Warbler and Calaveras Warbler.

Split Yellow-rumped Warbler into three species, Audubon's, Myrtle and Goldman's Warblers.

Split Guerrero Brushfinch from Chestnut-capped Brushfinch.


Split Yellow-eyed Junco by recognizing Baird's (endemic to Baja California) and Guatemalan Yellow-eyed Juncos (endemic to Chiapas and Guatemala) as full species, but lump the other remaining Yellow-eyed Junco subspecies with Dark-eyed Junco. I don't see the lump portion of this proposal going through, but then again I am not a committee.

Split Red Crossbill into two species, elevating the "South Hills Crossbill" from "type" to full species status. South Hills Crossbill is endemic to mountain ranges in Cassia County, Idaho.

Lump Common and Hoary Redpolls.

Split White-faced Ground-Sparrow from Prevost's Ground-Sparrow.

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