- Order: Cuculiformes
- Family: Cuculidae
- Polytypic 14 Subspecies
Squirrel Cuckoos are large arboreal cuckoos with a very long, graduated tail. The upperparts are rufous brown; the throat and breast are buffy; and the belly is light gray. The long tail is rufous above but the undersides of the rectrices are blackish, with broad white tips. The name 'Squirrel Cuckoo' comes from their coloration and the fact that their movements in trees resemble those of a squirrel at first glance.
In much of its range, the Squirrel Cuckoo is highly distinctive and is unlikely to be confused with any other species. The Squirrel Cuckoo is very similar to the Black-bellied Cuckoo (Piaya melanogaster) of the humid lowlands of northern and central South America east of the Andes, and the range of Squirrel Cuckoo completely overlaps that of Black-bellied. The Black-bellied Cuckoo differs by its distinct gray crown, red (not greenish yellow) bill, yellow loral spot, blue (not yellow or red) orbital ring, and blackish (not gray) belly. In Amazonia, the two species also differ in habitat preferences, with Black-bellied in terra firme forest and Squirrel in seasonally flooded forest and forest edge (Hilty and Brown 1986, Schulenberg et al. 2007); but elsewhere the two species may overlap in habitat, and may even be interspecifically territorial (Hilty 2003).
The Squirrel Cuckoo vocalizes infrequently, but has a remarkable variety of loud, distinctive calls:
A raspy call, variously transcribed as "jicaro" (Skutch 1966); "a loud kikerah or geep-kareer" (Ridgely and Gwynne 1989); "a gruff, nasal chek-e-rehr or sheh-k-ker" (Howell and Webb 1995); and "a sneezing rhi-KID'd'oo" (Lane, in Schulenberg et al. 2007).
A two-noted call, variously transcribed as "eee-kah," with the last syllable sometimes drawn out (Skutch 1966); "a dry chick, kwah" (Ridgely and Gwynne 1989); "a sharp, woodpecker-like chik, typically followed by a gruff snarl, whrrr" (Howell and Webb 1995); and "an explosive KEEK! wahh (source of vernacular name chiqua)" (Lane, in Schulenberg et al. 2007).
A flight call, transcribed as "a loud trrt-trrt-trrt-trrt" (Ridgely and Gwynne 1989); "a short buzzy or jangling djet! or djet!-djet!-djet!" (Hilty 2003); and as "a series of sharp kleh! notes" (Lane, in Schulenberg et al. 2007). Sometimes a single or double note, e.g., "a loud stit or stit-it" (Willis and Eisenmann 1979).
A rattle, described as "a rapid, chattering rattle punctuated with gruff ch'kerr calls (Howell and Webb 1995); and as "a dry throaty rattle" (Lane, in Schulenberg et al. 2007).
The song is a "monosyllable repeated many times over in measured cadence: whip-whip-whip-whip . . . ... It may be either loud and sharp or low and soft; or the opening notes in the series may be loud and clear, while succeeding ones become weaker until the last are faint and squeaky" (Skutch 1966); "a series of 5-8 ringing wheep notes (Willis and Eisenmann 1979); "a steady, often prolonged series of sharp notes pee'uk pee'uk ... or wheek wheek ... [given at a rate of] 10/4-6 s" (Howell and Webb 1995); and "a series of sharp, rising whistled whik or wheep notes" (Lane, in Schulenberg et al. 2007).
Detailed Description (appearance)
The following description is based on Ridgway (1916), Dickey and van Rossem (1938), and Wetmore (1968), and refers to Piaya cayana thermophila:
Adult: Sexes similar. Upperparts chestnut to rufous-chestnut, usually paler on the crown. Remiges tipped with grayish brown. Tail long, graduated. Rectrices rufous-chestnut above with a broad white terminal spot and a black subterminal bar; the underside of the rectrices primarily brownish-black, with a broad terminal white spot. Throat and breast cinnamon. Belly gray, shading to slate to slaty black on the flanks, crissum, and undertail coverts. Underwing coverts light gray; underside of remiges cinnamon-buff.
Immature (Formative plumage): Similar to adult, but rectrices (retained from the Juvenile or First Basic plumage) are narrower, with more pointed tips, and (especially on the central pair) the white tips and the black subterminal bar are reduced in size.
Juvenile (First Basic plumage): Similar to adult, but the plumages is more lax and fluffy, and the throat is a little grayer. The rectrices are narrower, with more pointed tips, and (especially on the central pair) the white tips and the black subterminal bar are reduced in size.
Iris: Carmine red, dark red (Ridgway 1916, Haverschmidt 1968, Wetmore 1968).
The color of the bare orbital skin is geographically variable; generally, the eyering is yellowish green from Mexico south to northern and northwestern South America, and is red from northern South America, east of the Andes, south to south central South America. The eyering is yellowish green to light olive-green from Mexico south to northwestern South America west of the Andes (subspecies mexicana, thermophila, and nigricrissa; Ridgway 1916, Wetmore 1968, Howell and Webb 1995, Ridgely and Greenfield 2001b, Schulenberg et al. 2007). The eyering color in northern Colombia and northwestern and northern Venezuela (subspecies mehleri, circe) apparently also is yellow (Restall et al. 2006), as it in Trindidad (insulana; ffrench 1991). From Venezuela south of the Orinoco, apparently south to the southern end of the distribution, the bare orbital skin is crimson (Haverschmidt 1968, Wetmore 1968, Belton 1984, Hilty and Brown 1986, Ridgely and Greenfield 2001b, Hilty 2003, Schulenberg et al. 2007).
Bill: Greenish yellow (Haverschmidt 1968)
Tarsi and toes: Bluish gray, lead gray (Ridgway 1916, Haverschmidt 1968)
Total length: 40-46 cm (Wetmore 1968), 40.5-46 cm (Ridgely and Greenfield 2001b), 40.5-50 cm (Howell and Webb 1995), 43 cm (Hilty and Brown 1986, Hilty 2003)
|wing length||tail length||bill length||tarsus length||n|
|(culmen from base)|
Mass: male, mean 104.0 g (range 73.0-137.0, n=33, taxa not specified; Payne 2005); female, mean 100.3 g (range 76.0-129.4 g, n=28, taxa not specified; Payne 2005)
subspecies thermophila: males, mean 99.4 g (± 9.0 g, range 89.2-111 g, n=7; Belize, Russell 1964); female, 103 g (Belize, Russell 1964).
subspecies insulata: males, mean 92.8 g (range 90-95.5 g, n=2; Junge and Mees 1958); females, mean 97 g (range 94-100 g, n=2; Junge and Mees 1958).
nominate cayana: males, mean 95 g (range 84-103 g, n=10; Suriname, Haverschmidt and Mees 1994); females, mean 95 g (range 82-103 g, n=6; Suriname, Haverschmidt and Mees 1994)
subspecies macroura: male, 134 g (Brazil, Belton 1984); mean 112 g (range 110-115 g, n=4; Argentina, Fiora 1933)
Little information, except for observations from El Salvador (Dickey and van Rossem 1938):
Definitive Basic plumage is acquired by a complete Prebasic molt. In El Salvador, the onset of this molt is variable, but the molt primarily is July-September.
Prealternate molt, which in El Salvador occurs in Feburary-March, is incomplete. The extent of this molt is not documented. The First Prealternate molt also is described as more extensive than the Definitive Prealternate molt.
Formative plumage is acquired by an incomplete Preformative molt. Juvenile (First Basic) rectrices and remiges are retained.
Juvenile (First Basic) plumage is retained for only a few weeks.
Many subspecies of Piaya cayana have been described; fourteen subspecies currently are recognized (Payne 2005). Subspecies designations are based on differences in size and in plumage color; the extent to which they correspond with differences in eyering color (see Bare Parts) sometimes is not clear. A modern, comprehensive review of geographic variation in Piaya cayana across multiple characters, including a genetic perspective, is overdue. The following outline of subspecies distributions and characters is based on Peters (1940) and Payne (2005):
thermophila Sclater 1859; type locality Jalapa, Veracruz, Mexico Occurs on the Gulf and Atlantic slopes from Mexico south to Panama and northwestern Colombia Relatively dark rufous-chestnut above; belly and undertail coverts dark gray to black; underside of rectrices black, white tips to rectrices relatively narrow.
mexicana (Swainson 1827); type locality Temescaltepec, Mexico Occurs on the Pacific slope of Mexico, south to the Isthmus of Tehuantepec Paler rufous-chestnut above; underside of rectrices rufous, with black subterminal bars and broad white tips.
nigricrissa (Cabanis 1862); type locality Babahoyo or Esmeraldas, Ecuador Occurs in western Colombia (east to the slopes of the central Andes), south of northwestern Peru Similar to thermophila, but plumage darker; belly and undertail coverts blackish.
mehleri Bonaparte 1850; type locality Santa Fé de Bogota (the same type locality as mesura?!) Occurs in northeastern Colombia, from the Gulf of Urabá to the Magdalena valley and the west slope of the eastern Andes, east along the coast of northern Venezuela to the Paria Peninsula More rufous than mexicana, with a lighter throat and breast that grade to light gray on the belly; underside of rectrices rufous.
mesura (Cabanis and Heine 1863); type locality Bogotá, Colombia Occurs in eastern Colombia, Ecuador, and Peru Similar in plumage to nigricrissa; smaller, but with overlap in size.
circe Bonaparte 1850; type locality Caracas, Venezuela Occurs in Venezuela, south of Lake Maracaibo Upperparts slightly more rufous than mehleri, but paler than nominate cayana.
cayana (Linné 1766); type locality Cayenne Widespread, from eastern and southern Venezuela east through the Guyanas, south to Brazil to the north bank of the lower Amazon Belly ashy gray; undertail coverts darker gray; colors otherwise similar to thermophila except that the belly and undertail coverts are not as dark; underside of rectrices black with white tips.
insulana Hellmayr 1906; type locality Chaguaranas, Trinidad Trinidad Similar to cayana, but undertail coverts black.
obscura Snethlage 1908; type locality Bom Lugar and Monte Verde, upper Rio Purús, Brazil Occurs from central Peru south to northern Bolivia, and east to central Brazil south of the Amazon, from the Rio Juruá east to the Rio Tapajóz Darker (less rufous) above; undertail coverts black.
hellmayri Pinto 1937; type locality Tury-assú, Maranhão Occurs from the lower Rio Tapajoz east to the mouth of the Amazon and the coast of Maranhão Upperparts more tan (less rufous) in color.
pallescens (Cabanis and Heine 1863); type locality Bahia Occurs in eastern Brazil Upperparts paler, more tan.
cabanisi Allen 1893; type locality Chapada, Mato Grosso Occurs in south central Brazil, from Mato Grosso east to Goiás and south to São Paulo More rufous; throat rusty; belly and undertail coverts pale
macroura Gambel 1849; type locality Paraguay Occurs in eastern Brazil (Bahia) south to Paraguay, northeastern Argentina, and Uruguay Upperparts dark; belly and undertail coverts blackish.
mogenseni Peters 1926; type locality Concepción, Tucumán, Argentina Occurs from southern Bolivia (Santa Cruz) to northwestern Argentina Upperparts lighter rufous; throat rusty; underparts dark gray (not blackish).
Most subspecies presumably intergrade where ranges abut. In southern Mexico, however, Binford (1989: 128) reported a few specimens intermediate between thermophila and mexicana, but noted that the "abruptness and apparent rarity of intergradation suggest that these two forms might be separate species.
Sorenson and Payne (2005) divide the cuckoos into five subfamilies, based on a phylogenetic analysis of mitochondrial DNA sequence data. Piaya falls in the subfamily Cuculinae, which is global in distribution. The sister genus to Piaya is the Neotropical genus Coccyzus. Traditionally Piaya contained three species, but Sorenson and Payne (2005) demonstrated that the Little Cuckoo forms a clade with two species formerly included in Coccyzus; these three species now constitute the genus Coccycua. Consequently, Piaya contains only two species, cayana and the Black-bellied Cuckoo Piaya melanogaster.
Fitzgerald, Jenny, Thomas S. Schulenberg, and Glenn Seeholzer. 2011. Squirrel Cuckoo (Piaya cayana), 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=201816