Peg-billed finch

The peg-billed finch (Acanthidops bairdi) is a passerine bird endemic to the highlands of Costa Rica and western Panama. Despite its name, it is not a true finch, but now recognized as a member of the tanager family (Thraupidae), after being long placed in the Emberizidae. It is the only member of the genus Acanthidops. The scientific name commemorates the American ornithologist Spencer Fullerton Baird.

The peg-billed finch is a long-tailed species, 13.5 cm long and weighing 16 g. It has a distinctive long upturned bill with a black upper mandible and yellow lower mandible. The adult male is slate grey, becoming paler on the belly. The female is olive-brown above, becoming paler below and with a grey tinge to the head and upper back. She has bright cinnamon wing bars and buff supercilia. Young birds are similar to the female, but have paler plumage and weaker wing bars.

It has a dry pzeek call, and the male's song consists of high whistled notes ending with a buzz, chee shee shee shee paah.