The thick-billed longspur, also known as McCown's longspur (Rhynchophanes mccownii), is a small ground-feeding bird in the family Calcariidae, which also contains the other longspurs and snow buntings. It is found in North America and is the only species in the genus Rhynchophanes.
Taxonomy
The thick-billed longspur was described in 1851 by the American amateur ornithologist George Newbold Lawrence under the English name rufous-winged lark bunting. He placed it in the genus Plectrophanes and coined the binomial name Plectrophanes mccownii. It was moved into its own genus Rhynchophanes in 1858 by Spencer Baird on account of its bill size and short spur, but was moved to Calcarius after a hybrid with the chestnut-collared longspur was discovered. It was once again placed in its own genus after a 2003 genetic study found it was more closely related to the snow buntings than the other longspurs.
"McCown's longspur" is no longer used by the American Ornithological Society, instead being changed to "thick-billed longspur", a literal translation of its genus name, Rhynchophanes. The IOC Bird List has followed suit with the name change.
The name "McCown" refers to Captain John P. McCown, a United States Army officer who collected the specimen in 1851 that led to the species first being scientifically described. which led to controversy starting in 2018, with parallels drawn to the removal of Confederate memorials. The pressure to change the name increased following the George Floyd protests and Black Birder's Week (itself a response to the Central Park birdwatching incident).
Description
The thick-billed longspur is about long, has a wingspan of and weighs around . It has a large cone-shaped bill, a streaked back, a rust-coloured shoulder and a white tail with a dark tip. In breeding plumage, the male has a white throat and underparts, a grey face and nape and a black crown. Breeding females are largely gray, with a pale bill and rusty tinged median coverts and scapulars. Non-breeding males are similar to females but with crowns spotted rather than streaked, and more chestnut on their median coverts and scapulars.
Juveniles are seen briefly in late summer and are more uniformly sandy, with a streaked upper breast and white belly.