Grallariidae – Antpittas

The Grallariidae (Antpittas) is a family of smallish suboscine passerines of subtropical and tropical Central and South America. They are between 10 and 20 cm in length, and are related to the antbirds, Thamnophilidae, and gnateaters, Conopophagidae.

They were also formerly placed in the Formicariidae, but studies (2002) and later DNA sequencing, indicated that a distinct family was supported and it was recognised as such (2008). There are seventy species very unevenly distributed among five genera.

They are forest birds, although the ranges of at least two species, Stripe-headed Antpitta Grallaria andicolus and Tawny Antpitta Grallaria quitensis, extend above the Andean treeline. that tend to feed on insects near or on the ground since many are specialist ant eaters. However, many eat a variety of arthropods and other invertebrates, and they feed a similar array of insects and earthworms to their young.

Most are drab in appearance with shades of (rusty) brown, black, and white being their dominant tones. Compared to other birds that specialise in following ants, this family is the most tied to the ground.

The long, powerful legs, which lend the birds a distinctive upright posture, and an essentially vestigial tail aid this lifestyle. This led to their common name although they are not related to true pittas.

Their breeding biology of is poorly known, as they live in heavily vegetated habitats and are generally very shy. However, it is thought that they are predominantly monogamous with co-parental care. The nests of fewer than half the species have been described, but those that have been are a simple cup of fine plant fibres, particularly small rootlets or strands of fungi, placed on a bed of leaves and small sticks. Nests are most often placed on a branch at a fork or against the trunk one to three metres up, although some use fallen trees, vines or palm leaves and at least one antpitta uses the old nests of other species.

Pale-billed Antpitta Grallaria carrikeri

Yellow-breasted Antpitta Grallaria flavotincta

They lay two or three eggs with both sexes incubating. Indeed, both adults appear to participate in nest construction, incubation, and feeding of the young, though in at least one species it appears that the female alone incubates. In observed species eggs are incubated around sixteen days and the chicks fledge between two and three weeks, before they are able to fly, although this is not an issue with such terrestrial species.

The antpittas are sexually monomorphic; they resemble the Old-World pittas in that they are virtually tailless; they hop like some thrushes, and are much easier to hear than see, although their whistling vocalisations may be rather atypical for perching birds.

Giant Antpitta Grallaria gigantea

Spotted Antpitta Hylopezus macularius

Most aspects of their biology have not been thoroughly studied, and, with reports of chicks that feign death when discovered by predators in the nest and mock-injured distraction displays in the parents, there is much more to learn about these distinctive birds.