Painted Antnest Frog

Appearance

The female "Lithodytes lineatus" grows to a length of between 38 and 52 mm, and the male is slightly smaller. It has a slender body and blunt snout. The overall colour is black apart from a pair of yellow lateral stripes running from the snout to the groin, where there is a red or orange patch. The limbs are brown banded with black.

This frog is similar in appearance to the brilliant-thighed poison frog and may benefit by mimicking the toxic species, as it is avoided by predators.

Distribution

"Lithodytes lineatus" is native to tropical South America. Its range includes the Orinoco basin and the Amazon basin and it is present in Colombia, Venezuela, the Guianas, Ecuador, Peru, Bolivia and Brazil. Its natural habitats are subtropical or tropical moist lowland forests, moist savanna, and intermittent freshwater marshes from altitudes ranging from sea level to 1,800 m above sea level. The species can be found below logs, among leaf-litter and in other concealed locations on the forest floor.

Status

This frog has a very wide distribution and is a common species, and its total population is estimated to be large. It may be in slight decline because of habitat degradation but seems to be able to adapt to secondary habitats. It is also present in a number of protected areas, so the International Union for Conservation of Nature has rated its conservation status as being of "least concern".

Habitat

This frog is often found in association with the leaf-cutter ant "Atta cephalotes", with the male frog having been found calling from the interior of an active ants nest, seemingly unattacked by the ants. The ants usually kill intruders into the nest, and the frogs captured at the entrance to the nest had a noticeable aromatic odour; it may be that this acts as a repellent or other chemical signal to the ants. In one instance, four male frogs were calling synchronously from the inside of a large ant nest, the call being a series of brief whistles at the rate of about 85 per minute. Examination of another nest showed various passages and a wide vertical tunnel inside descending to the water table, with foam nests attached to roots in the wall of the tunnel and tadpoles at various stages of development in the underground pool. Ants were also moving along these tunnels. The frogs benefit from this association in that they have a well-protected breeding site and are safe from predation. It is not clear whether the ants benefit from the arrangement, but an examination of the contents of two frogs' stomachs showed that their diet included earthworms, crickets, isopods and insect larvae, with less than 10% being ants. Male frogs of this species have been observed calling at the entrance to, and from inside, an "Atta laevigata" nest, and juvenile frogs have been observed emerging from a nest of "Atta sexdens".

Reproduction

These frogs build foam nests at the edge of temporary pools, and the tadpoles develop within these. The frogs also associate with certain leafcutter ants and breed inside their nests without being attacked by the ants.