Notice for readers: On March 31, Neotropical Birds will be integrated into the new Birds of the World, a powerful research database offering species accounts for every species on earth. Learn more at While Birds of the World is a subscription service, we remain committed to offering this content to Neotropical Birds contributors and to those unable to pay for it through our scholarship program. Stay tuned.

Mountain Avocetbill Opisthoprora euryptera

  • Order: Caprimulgiformes
  • Family: Trochilidae
  • Monotypic
  • Authors: Thomas S. Schulenberg


Distinguishing Characteristics

Mountain Avocetbill is a small but heavy bodied, plain colored hummingbird, and is the only species in the genus Opisthoprora. Its most notable feature is its short black bill, which is sharply recurved at the tip, somewhat recalling the form of the bill of an avocet (Recurvirostris). Otherwise the avocetbill is green above, with a white postocular spot. The underparts are white, heavily streaked with dark green. The tail is notched, and the outer rectrices have narrow white tips. There is no brilliant throat patch or gorget, and the sexes of Mountain Avocetbill are similar.

Similar Species

The shape of the tip of the bill of Mountain Avocetbill is unique among Andean hummingbirds, but can be difficult to see sometimes under field conditions. Otherwise this species is distinguished from similarly sized species (such as metaltails Metallura) by its streaked (not spotted) underparts.

Detailed Description

The following description is based on Fjeldså and Krabbe (1990) and on Schuchmann (1999):

Adult: Sexes similar. Upperparts bronzy green, with a prominent white postocular spot. Central pair of rectrices bronzy green; outer rectrices dark blue with narrow whitish tips. Tail notched. Underparts white, with rufous flanks and belly, and throughout streaked with dark green.



Bare Parts

Iris: black

Bill: black

Toes: pinkish brown

Bare part color data from specimens in the Louisiana State University Museum of Natural Science.


Total length: 10 cm (Fjeldså and Krabbe 1990, Ridgely and Greenfield 2001b), 10.2 cm (Hilty and Brown 1986), 11 cm (Schulenberg et al. 2010)

Linear measurements:

bill length: 1 cm (Fjeldså and Krabbe 1990), 1.3 cm (Hilty and Brown 1986, Ridgely and Greenfield 2001b, Schulenberg et al. 2010)

Mass: male, 6.4 g, 6.6 g; female, 5.8 g, 6.2 g (data from specimens in the Louisiana State University Museum of Natural Science)

Recommended Citation

Schulenberg, T. S. (2014). Mountain Avocetbill (Opisthoprora euryptera), version 1.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA.