Straneck's Tyrannulet vs Rough-legged Tyrannulet

In short

Straneck's Tyrannulet and Rough-legged Tyrannulet can be differentiated by their structure and plumage. Straneck's Tyrannulet has a rounder crown and a smaller-looking bill compared to the Rough-legged Tyrannulet, which has a more typical tyrannulet structure with a gray crown and olive upperparts. Vocalizations are a key differentiator, with Straneck's Tyrannulet having distinct calls.

Identification tips

• Crown and Bill: Straneck's has a rounder crown and smaller-looking bill.
• Plumage: Look for greenish back and yellow belly in Straneck's; olive upperparts and gray crown in Rough-legged.
• Vocalizations: Use calls to confirm Straneck's Tyrannulet.
• Migration: Consider location and season; Straneck's may be a migrant in some areas.

Size

Both species are small tyrannulets, but Straneck's Tyrannulet appears slightly less elongated.

Plumage

Straneck's Tyrannulet shows a greenish tone to the back and some yellow on the belly, while Rough-legged Tyrannulet is olive above with a gray crown, two yellowish wing bars, and pale-yellowish underparts.

Habitat

Straneck's Tyrannulet breeds in the Monte region and W Chaco in Argentina and migrates eastward in winter, reaching W Uruguay. Rough-legged Tyrannulet's habitat details are less specific but generally align with typical tyrannulet environments.

Voice

Vocalizations are the best way to find Straneck's Tyrannulet, as it has distinct calls compared to other similar species.