The New Neotropical Companion

Suboscine and Oscine Birds:

Neotropical Uniqueness

By far the largest bird order is the Passeriformes, perching

birds, of which there are 5,899 species, representing

about 60% of all extant bird species. Of this assemblage,

1,263 are within a group classified taxonomically as

suboscines. This is of interest because there are 1,213

species of suboscine birds in the Neotropics and only

50 suboscine species in all of the rest of the world.

Thus the Neotropics are unusual in harboring so many

members of this group. Most passerines in the world

are true oscines, or songbirds, which have a complex

musculature of the syrinx (the avian voice box, located in

the bronchial area), the part of the trachea that produces

elaborate, complex sounds, such as the flutelike songs

of various thrushes (plate 15- 96) and solitaires and the

sweet whistle of an oriole. Suboscines are different. These

birds have a much less complex syringeal musculature

and thus have far more limited singing abilities than

true oscines. In addition, true oscines typically learn and

refine their songs, whereas the simple vocalizations of

most suboscine species (except for some cotingas) are

not learned— they are innate.

Neotropical suboscines have undergone two major

adaptive radiations, with the tyrant flycatchers,

cotingas, and manakins representing one, and the

ovenbirds (including woodcreepers), antbirds,

antthrushes, antpittas (plate 15- 97), gnateaters, and

tapaculos representing the other. No one knows why

suboscines have fared so well in the Neotropics, but the

reason simply may be historical. The tyrant flycatchers

are discussed in chapter 8, and the cotingas and

manakins are discussed earlier in this chapter. Now it

is time to look at some other suboscines.

There are 296 species of ovenbirds and woodcreepers

(Furnariidae), 217 species of typical antbirds

(Thamnophilidae), 12 species of antthrushes

(Formicariidae) and 51 species of antpittas

(Grallariidae), as well as 410 species of tyrant flycatchers

(Tyrannidae). Of the above groups, only a few of the

tyrannids venture to North America to nest. All others

are entirely Neotropical.

Furnariids: Ovenbirds and Woodcreepers

Ovenbirds (family Furnariidae, order Passeriformes)

are the “little brown birds” of the American tropics,

their plumage typically a mixture of brown, tan, buffy,

Plate 15- 97. The Chestnut- naped Antpitta (Grallaria nuchalis) is

a suboscine that ranges from Colombia to Peru. It has a simple

and short song. Like other antpittas, it is a forest understory

species that feeds heavily on insects and other arthropods.

Photo by Steve Bird.

Plate 15- 96. The Rufous- bellied Thrush (Turdus rufiventris),

which happens to be the national bird of Brazil, is a fine

example of an oscine passerine. Like all thrushes, it has an

excellent singing voice (and often sings in early morning

before first light), a reason it is much loved by Brazilians. Photo

by John Kricher.

Plate 15- 98. The plumage of the Rufous- fronted Thornbird

(Phacellodomus rufifrons) is, like that of virtually all members of

the large family Furnariidae, a study in brown. Photo by John

Kricher.

chapter 15 neotropical birds: the bustling crowd 297