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Glaucidium hardyi

Amazonian Pygmy-Owl

  • Order: Strigiformes
  • Family: Strigidae
  • Monotypic

Authors: Schulenberg, Thomas S

Identification

Summary

Pygmy-owls (Glaucidium) are very small owls, with a large rounded head and a pair of prominent black marks (false "eye spots") on the nape. Amazonian Pygmy-Owl is a small species of Glaucidium, with a relatively short tail. The crown is grayish brown, finely spotted with small white dots, and contrasting with the brown wings and back. The underparts are white, marked with broad brown or rufous brown streaks.

Similar Species

Amazonian Pygmy-Owl overlaps geographically with Ferruginous Pygmy-Owl (Glaucidium brasilianum), although these two species usually segregate by habitat: Amazonian occupies the canopy of the interior tall lowland forest, and Ferruginous occurs at forest edge and in lower, more open river-edge forest. Ferruginous also has narrow pale streaks (not small spots) on the crown; is larger; and has a longer tail, with a greater number of transverse pale buffy bars (5-7 bars on the upper surface of the tail, or 3-5 bars on the under surface of the tail, as opposed to 2-4 whitish bars on the tail of Amazonian). Ferruginous and Amazonian pygmy-owls also differ dramatically in vocalizations.

Amazonian Pygmy-Owl also is very similar to species in the Least Pygmy-Owl group (Tamaulipas Pygmy-Owl G. sanchezi; Colima Pygmy-Owl G. palmarum; Central American Pygmy-Owl G. griseicepsSubtropical Pygmy-Owl G. parkeri; Pernambuco Pygmy-Owl G. mooreorum; and Least Pygmy-Owl G. minutissimum), but is separated geographically or elevationally from all of these species.

Vocalizations

The song of Amazonian Pygmy-Owl is a short trill, and is not always immediately recognizable as being given by an owl (Hilty 2003). This vocalizations variously is described as "a slightly descending, melancholy, rapid series of whistled notes: tutututututututututo (about 10 notes/sec)" (Lane, in Schulenberg et al. 2010), or as "a series of c. 10-30 short, fluted notes in a rapid 'staccato' sequence (c. 10-13 notes per second), each phrase lasting c. 2.5-3 seconds and repeated at variable intervals: bybybybybybybybybybyby.....bybyby, or bübübübübübübübü....bübübübü" (König and Weick 2008).

Nonvocal Sounds

None reported.

Detailed Description (appearance)

The following description is based on König and Weick (2008):

Adult: Sexes similar. Crown grayish brown, with numerous very small white or off white spots. Nape with typical Glaucidium "false eyes" pattern of two large blackish spots, outlined with a narrow pale border. Back and rump brown, with a rufous tinge. Wing coverts similar, but with a few obscure whitish spots. Remiges dark brown, irregularly barred with whitish spots. Rectrices dark brown with three irregular bars of large whitish spots. Facial disk pale grayish brown with small brownish flecks. White line above the eye and extending along the upper edge of the facial disk. Underparts off white. Sides of breast densely mottled with rufous brown; lower breast and flanks with coarse reddish brown streaks. 

Rufous morph apparently very rare or absent. König and Weick (2008) ascribe one specimen, from northwestern Venezuela (Cerro del Ávila, near Caracas) to a rufous morph of hardyi. This species otherwise is documented only from eastern Venezuela (Hilty 2003), however, and so the identity of this specimen is not confirmed.

Juvenile: Similar to adult, but crown unspotted, and the streaking on the underparts is less distinct.

Bare Parts

Iris: bright yellow, golden yellow

Bill: maxilla yellow green, tip yellow; mandible yellow

Cere: dull yellow

Tarsi and toes: orange yellow, golden yellow

Bare parts color data from König and Weick (2008) and personal observations.

Measurements

Total length: 14 cm (Hilty 2003), 14-15 cm (König and Weick 2008)

Linear measurements:

wing length, male, mean 92.2 mm (range 90-93 mm, n = 5; Vielliard 1989); female, 94 mm (n =1; Vielliard 1989); range 91-96 (mean? n?; König and Weick 2008)

tail length, male, mean 49.4 mm (range 45-52 mm, n = 5; Vielliard 1989); female, 49.5 mm (n =1; Vielliard 1989); range 45-53 (mean? n?; König and Weick 2008)

Mass: male,  57 g, 63 g (n = 2; König and Weick 2008)

Molts

No information available - Contribute

Geographic Variation

Monotypic.

Systematics

Until recent decades, this species was not recognized as distinct from Glaucidium minutissimum (Least Pygmy-Owl), which now is considered to be restricted to Atlantic forests of southeastern Brazil. Described as Glaucidium hardyi by Vielliard (1989), with a type locality of "20 km SW Presidente  Médici, Rondônia", Brazil. The holotype is in the Departamento de Zoologia da Universidade Estadual de Campinas, Brazil. The species is named in honor of Dr. John William "Bill" Hardy, in recognition of his important contributions to the study of Neotropical birds in general, and to sound recording in particular.

There are no comprehensive phylogenetic surveys of Glaucidium. One analysis, with a limited number of taxa and a relatively small amount of DNA sequence data, suggests that hardyi is sister to Glaucidium jardinii (Andean Pygmy-Owl) and Glaucidium bolivianum (Yungas Pygmy-Owl) (Wink et al. 2008).

Recommended Citation

Schulenberg, Thomas S. 2012. Amazonian Pygmy-Owl (Glaucidium hardyi), Neotropical Birds Online (T. S. Schulenberg, Editor). Ithaca: Cornell Lab of Ornithology; retrieved from Neotropical Birds Online: http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=211736