- Order: Passeriformes
- Family: Tyrannidae
Myiopagis are small tyrant flycathers with a relatively small bill and relatively long tail. Most species have wing bars and a concealed white or yellow patch in the center of crown. Myiopagis are very similar to "true" elaenias (Elaenia), but are smaller, and the pale crown patch of most Elaenia is more conspicuous. Foothill Elaenia has a grayish crown, with a concealed white crown patch. The upperparts otherwise are mostly olive, with pale yellow wing bars. The throat is white, and the breast and belly are yellow. Foothill Elaenia is similar to several other species; see Similar Species.
Foothill Elaenia is similar to two other sympatric species of Myiopagis, Forest Elaenia (Myiopagis gaimardii) and the female of Gray Elaenia (Myiopagis caniceps). Note that the elevational distribution of Foothill Elaenia is largely (although not entirely) above that of Forest and Gray elaenias, and that it differs most notably in vocalizations. In terms of plumage, Foothill Elaenia differs from Forest Elaenia by "having a greener ... back without any brownish wash; pure dark gray rather than gray-brown crown; shorter and broader crown feathers; pure white instead of yellowish white or pale yellow coronal patch; by having three well-defined instead of two ill-defined wingbars ... by coronal patch being more concealed; and by having the white feathers of the coronal patch tipped with gray instead of blackish gray-brown" (Coopmans and Krabbe 2000: 306).
From the female of Gray Elaenia (Amazonian subspecies, cinerea), Foothill Elaenia is distinguished by the gray, not olive, crown, and by concealed, white crown patch; the crown patch of cinerea is mostly yellow, and is only semiconcealed (Coopmans and Krabbe 2000).
The song of Foothill Elaenia is described as "an about 2 s long harsh trill at a rate of approximately 14 notes per second at 4-6 kHz, distinctly rising in pitch, and preceded by introductory notes that vary in number, pace, and rhythm" (Coopmans and Krabbe 2000), and as a "rising trilled t'teerrreeeeeeee. Also a rising series, tew-tew-tew, which may accelerate into a longer, rising trill" (Lane, in Schulenberg et al. 2010).
Additional recordings of vocalizations of Foothill Elaenia can be heard at Macaulay Library and at xeno-canto.
Detailed Description (appearance)
The following description is based on Coopmans and Krabbe (2000):
Adult: Sexes similar. Crown dark gray. Concealed white patch in center of crown, feathers with gray tips. Back olive green. Wings dusky, washed with olive green on the lesser wing coverts. The outer web of the tips of the wing coverts with pale yellow, forming three well defined wing bars. Tertials with well defined pale yellow edges on outer webs. Secondaries narrowly edged pale yellow, except for the basal 5 mm. Primaries very narrowly edged olive green, except on the terminal 10 mm. Rectrices slightly browner than wings, and narrowly edged olive green. Lores, eyering, subocular region, and auriculars mottled gray and white. Throat whitish, slightly mottled with gray. Remaining underparts sulphur yellow, lower throat and (especially) the breast clouded with olive (producing a slightly streaked appearance).
Bill: maxilla blackish; mandible blackish, extreme base brownish gray or gray-brown
Tarsi and toes: blackish
Bare parts color data from Coopmans and Krabbe (2000).
Total length: 12-12.5 cm (Fitzpatrick 2004), 12.5 cm (Ridgely and Tudor 2009)
Linear measurements, from Coopmans and Krabbe (2000):
Described as Myiopagis olallai by Coompans and Krabbe (2000). The type locality is "at Río Bombuscaro (04º07'S, 78º58' W) 5 km south-southeast of Zamora, Province of Zamora-Chinchipe, Ecuador, elevation 1000 m", and the type specimen is in the Museo Ecuatoriano de Ciencias Naturales, Quito.
This species was discovered only in 1992 by the late Paul Coopmans, who "tape-recorded and observed a flycatcher at an elevation of about 1000 m near Zamora in southeastern Ecuador ... He could not assign the vocalizations to any species he knew" (Coopmans and Krabbe 2000). Further field work confirmed Coopmans' inital assessment that the unidentified tyrannid constituted a previously overlooked, undescribed species.
Myiopagis olallai is named after the late Alfonso Manuel Olalla of Ecuador, "in appreciation of his unparalleled contribution to Neotropical ornithology. Of the over 70,000 specimens (most are housed in American Museum of Natural History, New York and Swedish Museum of Natural History, Stockholm) he and members
of his family collected, notably his father Carlos and brother Ramon, he collected the vast majority, in Venezuela, Colombia, Ecuador, Peru, Bolivia, and Brazil. These specimens form the main basis of our knowledge of the distribution and variation of birds in many of these areas, especially in Amazonia" (Coopmans and Krabbe 2000; see also Wiley 2010).
Myiopagis olallai is most similar to Myiopagis caniceps (Gray Elaenia) and to Myiopagis gaimardii (Forest Elaenia). Fitzpatrick (2004) suggested that olallai is "probably most closely related" to caniceps. Rheindt et al. (2009) investigated the phylogenetic relationships within Myiopagis, based on DNA sequence data from a mitochondrial gene and a nuclear intron. Rheindt et al. (2009) identified Myiopagis olallai as nested within Myiopagis caniceps (but as sister to nominate caniceps), strongly suggesting that the latter represents at least two species.
Lanyon (1988), in a phylogenetic analysis of cranial and syringeal characters, identified Tyrannulus as the sister genus to Myiopagis, with Elaenia basal to this pair. A phylogenetic analysis of DNA sequence data, from both mitochondrial and nuclear genes indicated that Myiopagis and Elaenia are sister taxa, but this study did not include Tyrannulus (Tello et al. 2009). Consequently the relationships between these three genera remain unresolved.
Schulenberg, Thomas S., and Guy M. Kirwan. 2012. Foothill Elaenia (Myiopagis olallai), 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=425161