Willets, Warblers, and Wrens: This Year’s Bird Name Updates and Species Splits

As scientists study birds, we learn more about how various kinds are related. Sometimes, two that had seemed different turn out to be such close relatives that they are “lumped” into one species. More often, slight variations turn out to be significant, and a bird is “split” into two or more species. Whenever these changes are published, serious birders are eager to see how their birding life lists will change.

 For years, updates had been published regularly by a committee of the American Ornithological Society (AOS)—the same committee that maintained the official list of North American bird species. Recently, a parallel list treating all birds of the world has been maintained by eBird, the app and database hosted by the Cornell Lab of Ornithology. Both the AOS and eBird published new updates in late October 2026, giving North American birders some new names to learn and a couple of new species to identify.

Although the two lists remain largely the same, they do differ in a few key ways. In the past year, the National Audubon Society—and, subsequently, Audubon magazine—has shifted to align with eBird’s global list due to Audubon’s expanding work across the Americas. So those are the names you will now find in the bird guide and all communications and stories moving forward. Here’s what else you need to know about the changes this year and where each list landed.

Why the Willet was split into two species

The Willet, a big, noisy sandpiper with a flashy wing pattern, is widespread in North America. Birders had long noticed differences between two populations, which are now formally recognized as distinct species on both the AOS and eBird lists.  

The western birds, now called Prairie Willets (Tringa inornata), nest around inland marshes from the Dakotas and the Canadian prairie provinces to eastern California. They migrate to coastal regions for the winter—abundantly along the Pacific Coast, but also all along the Gulf Coast and southern Atlantic Coast, north to New Jersey and sometimes farther. During migration they may be seen throughout the interior of the West and scattered through the eastern states, especially around the Great Lakes.

Saltmarsh Willets (Tringa semipalmata) nest in salt marshes (appropriately enough), all along the Gulf and Atlantic coasts, from Texas to eastern Canada. They spend the winter in coastal regions of Central and South America, with some making long overwater flights to get there. They are almost never found inland; even in eastern North America, almost all Willet records involve the Prairie species.

These two species often can be separated by range and season, but they overlap along the Gulf and Atlantic coasts during migration seasons. The Prairie Willet averages larger in size. Both species are plain pale gray-brown in winter plumage, barred with black in breeding plumage, but the Prairie Willet averages paler at all seasons. Bill shape is one of the best field marks: That of the Saltmarsh Willet is heavier, with a thicker tip, while that of the Prairie Willet is thinner and more tapered, giving the impression of being longer.

A tale of two Marsh Wrens—finally

Chattering and sputtering as they lurk among the cattails, Marsh Wrens are widespread from coast to coast. More than 40 years ago, researchers noticed an intriguing pattern: Males in the West sang more different songs than their eastern cousins. Ongoing studies gradually revealed other differences, including genetic ones. It turns out they are entirely separate species, now officially recognized by the AOS and eBird.

The Western Marsh Wren (Cistothorus paludicola) and Eastern Marsh Wren (Cistothorus palustris) can be identified by range in most areas, but they meet on the Great Plains and in the Canadian prairie provinces, and telling them apart there is a subtle challenge. Visually they are very similar. Their songs differ slightly. That of the Western is harsher and more variable, with many rattling sounds, and begins with one or more hard chuck notes. That of the Eastern often begins with a buzzy note, going on into a slightly musical bubbling series. Birders hoping to identify these wrens in the middle of the continent should try to study recordings first, such as the many online examples in the Macaulay Library at the Cornell Lab of Ornithology.

Catching up on warblers and whimbrels

Two species splits announced by eBird in 2025 are now officially recognized by the AOS as well. The Whimbrel, that big curve-billed shorebird, is now separated into the Hudsonian Whimbrel (Numenius hudsonicus) in the Americas and the Eurasian Whimbrel (Numenius phaeopus) in the Old World. The Eurasian species, best recognized by its white or pale rump, is a regular vagrant to North America with dozens of records, especially in Alaska.

The Yellow Warbler, meanwhile, has long been considered one of the most widespread breeding members of its family, nesting everywhere from the Arctic to South America. Now its range has been cut in half, with the Northern Yellow Warbler (Setophaga aestiva) widespread in North America during the breeding season, and the Mangrove Yellow Warbler (Setophaga petechia) resident along coastlines from Mexico and the Caribbean to South America and the Galapagos Islands. In the United States, Mangrove Yellow Warblers can be found in the Florida Keys and nearby in the Everglades, as well as at the southern tip of the Texas coast. Those in Florida look very similar to the Northern Yellow Warbler but with a darker cap, tinged reddish in the males. In Texas, male Mangrove Yellow Warblers are easily recognized by their chestnut-red heads. 

More notable bird name updates for 2026 

In addition to these big splits, a few other birds gain new names this year, for a variety of reasons, on both the AOS and eBird lists.

The Painted Redstart (locally common in the Southwest) becomes Painted Whitestart, and Slate-throated Redstart (a rare visitor there) becomes Slate-throated Whitestart. Birders have been suggesting this change for years. The name “redstart” originally applied to several small songbirds of Eurasia with reddish tails; the “start” came from Old English “steort,” meaning tail or rump. In our American Redstart, a warbler unrelated to these Eurasian birds, the male also has reddish in the tail. But the warbler we have long called Painted Redstart has flashy white outer tail feathers instead, so “whitestart” seems reasonable.

The Tufted Flycatcher becomes Tawny Tufted-Flycatcher. This perky-crested sprite, a rare visitor to the southwestern states, gains a new modifier because of a split from another species found farther south.

The Red-legged Thrush, a very rare visitor to Florida, is now Western Red-legged Thrush because of a split from another form found farther east in the Caribbean.

The name Fea’s Petrel was formerly applied to a complex of seabirds nesting on islands in the eastern Atlantic and showing up as rare visitors off our southeastern coast, especially off North Carolina. That complex has now been split into three species and the name “Fea’s” has been retired. The birds appearing in our waters are considered likely to be Desertas Petrels, although Zino’s and Cape Verde Petrels are also possible, and identification will be an ongoing challenge owing to the extreme similarity of all three forms.  

And birders who track scientific names will note that Winter Wren changes from Troglodytes hiemalis to Nannus hiemalis, and Pacific Wren changes from Troglodytes pacificus to Nannus pacificus.

Where AOS and eBird diverged on name changes   

This year’s AOS update included a few departures from eBird’s treatment, and these disagreements will cause some confusion for birders. On species splits, the AOS lists Western Marsh-Wren and Eastern Marsh-Wren; eBird drops the hyphen and lists Western Marsh Wren and Eastern Marsh Wren. What eBird called Northern Yellow Warbler and Mangrove Yellow Warbler, the AOS calls Yellow Warbler and Mangrove Warbler.

The biggest difference involves Great Egret, long considered a worldwide species. The AOS has just split it into two, with Great White Egret widespread in Eurasia, Africa, and Australia, and American Egret in the Americas. Great White Egrets have been found a few times in western Alaska, but they’re extremely rare elsewhere in North America. They differ from American Egrets in usually having the bill all-black in the breeding season, not yellow, and in having variable amounts of yellow or pink on the legs.  

For the moment, either name for the North American population might be considered correct—American Egret or Great Egret—but only the Great Egret has a banding code that has come to be a beloved shorthand name for the species among birders: GREG.