Plain-crowned Spinetail Synallaxis gujanensis Scientific name definitions

The Plain-crowned Spinetail is a widespread furnariid of northern South America. Found in the Guianas and much of Amazonia, the species is distributed locally in varzea undergrowth and river island forest below 1200 meters in elevation. It is brown above with a pale buff superciliary, rufous wings and tail, and white underparts with tan-buff flanks. Plain-crowned Spinetail is difficult to see due to its skulking nature, and is best detected by listening to its sharp, two part call given as a contact call between members of pairs.

15–17 cm; 13–22 g. One of the dullest and plainest Synallaxis. Nominate race has mostly plain dull greyish-brown face, hint of greyish-buff supercilium; crown and back  to uppertail-coverts dull brownish, slightly darker and greyer on forecrown; wings  dark rufous, duller tips of remiges; tail graduated, 10 rectrices, tips sharply pointed, shafts slightly stiffened, dark rufous; throat  whitish, blending to brownish breast, flanks and undertail-coverts, belly paler; iris brown to light brown; upper mandible blackish, lower mandible grey to pale grey, sometimes with blackish tip; tarsus and toes olive-grey to greenish-yellow, or blue-grey. Sexes alike. Juvenile  has faint dusky scalloping on breast. Race columbiana has much whiter underparts than nominate, with greyer, less tawny, flanks; <em>huallagae</em> is darker and greyer , flanks olivaceous; <em>canipileus</em> resembles previous, but crown and underparts greyer, contrasting more with back, wings and tail slightly paler; inornata has upperparts a richer brown, especially on crown, auriculars more buffy, underparts much brighter rusty; certhiola is like previous, but auriculars more greyish, hindcrown greyer, back paler and more olivaceous (less rufescent), wings and tail paler, underparts conspicuously paler, centre of belly buffy white, underwing-coverts lighter ochraceous.

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Editor's Note: Additional distribution information for this taxon can be found in the 'Subspecies' article above. In the future we will develop a range-wide distribution article.

Arthropods; Orthoptera and larvae of Lepidoptera recorded. Usually in pairs. Gleans items from small branches, foliage and grass within 1–2 m of ground; also on ground .

Song  a sharp “téw, hu” or “kéék, uh”, second note much lower-pitched than first  , distinct pause between the two, often repeated for long periods; race inornata  song differs, “chew, chu-whee” or “pyeeew, pip-sweet”, first note more downward-inflected and third note upward-inflected, thus more like that of S. albilora. Also gives short trill followed by querulous note, “ttttd-cheeoo”.

Eggs in Jan, Mar, May–Sept and Dec in Surinam. Presumably monogamous. Nest  a globular mass c. 65 cm long × 25 cm × 25 cm, made of sticks, entrance hole to horizontal tunnel at long end, placed 1–2 m above ground in low, dense vegetation; territory size in SE Peru c. 2 ha. Clutch 2–3 eggs. Nests often parasitized by Striped Cuckoo (Tapera naevia) in Surinam.