Thick-billed Seed-Finch Sporophila funerea Scientific name definitions

The seed-finches are a bit of a taxonomic puzzle. First of all, they are closely related to Sporophila seedeaters and some consider them best all lumped into one genus; the seed-finches being the larger and bigger billed extremes within the group. The other issue is that the few seed-finches that exist are rather similar looking and have been variously treated as subspecies of each other in different arrangements during the past. The Thick-billed Seed-Finch is found in Central America to NW South America. Curiously, it hybridizes with the very different looking Chestnut-bellied Seed-Finch (O. angolensis) in the Magdalena Valley of Colombia; the two have been treated as conspecific in the past and been given the name “Lesser Seed-Finch.” The Thick-billed Seed-Finch has all black males with white bases to the primaries, forming a white “speculum” or “handkerchief” on the closed wing. The females are a rich warm rusty brown. As is typical of the group the bill looks oversized, and in this species it is black. Its nest is lined with horsehair, so thin that light passes through it.

10·7–12·5 cm; 12·8–13·9 g. Small, with large, very deep-based bill (larger than Sporophila). Male nominate race is all black, except for white at bases of primaries and secondaries (mostly concealed), and white underwing-coverts; iris black; bill and legs blackish. Female is dark brown above, paler cinnamon-brown below, lacks white in primaries; bare parts as for male. Juvenile is like female. Races differ in depth of colour of females and subadult males: salvini is much more richly coloured than others, with underparts deep reddish-chestnut; aethiops is similar to previous, but more sooty (less reddish) above and below; ochro­gyne is much paler than others.

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Humid forest edge, grassy and shrubby fields with scattered shrubs and trees, second growth and tall grass; usually found in scrub in grassy areas; more arboreal than other seedeaters. Lowlands to 1100 m, usually below 500 m.

Sedentary.

Feeds on grass seeds, including hard-shelled seeds of a grass in genus Olyra. Forages in dense vegetation; flicks wings and tail in nervous manner. Singly and in pairs; sometimes in small groups, occasionally with other seed-finches.

A series of sweet, slurred whistles and warbles, “techu techu chu chi techu chu chi...”, duration 4–20 seconds. Call a slurred “tchew” or staccato “dik”.

Season Apr–Sept in Middle America and May–Oct in Colombia. Nest a slight cup of rootlets, fibres and grasses, lined with finer rootlets and spider webs, placed up to 1 m above ground or water in bush, dense tree or vine tangle. Clutch 2–3 eggs, dull greenish-white, heavily spotted with brown or lilac. No other information.

Not globally threatened. Locally fairly common; common on Coiba I, off S Panama; uncommon to rare in Mexico. Apparently increasing in numbers in Darién, Panama, following clearing of forest.