PAINTED MANTELLA

Characteristics

Dressed in a spectacular array of contrasting colors—with orange, black, yellow, green, and blue appearing to varying degrees and patterns on different individuals—painted mantella frogs may be tiny, but they make a big splash in the forest. Their striking coloration is a signal to warn potential predators that they are toxic, much like the bright colors of dart frogs in Central and South America. While mantellas and dart frogs look similar, they are actually not closely related, which is an example of convergent evolution: two unrelated animals that evolve similar adaptations independently.

Habitat

The painted mantella is endemic to Madagascar, found in eastern-central Madagascar from Fierenana to Andringitra. This frog is found in rainforest, forested swamps, stream-side thickets, and bamboo groves. It is somewhat adaptable to variations in habitat, but it is typically found near rivers and streams. It is terrestrial, spending its time on the ground among leaves and rocks.

Diet

Painted mantella frogs feed on insects, which they capture with their long tongue. The largest part of their diet is ants, particularly Anochetus grandidieri, but they also consume beetles and mites. It is this diet that makes these frogs poisonous: high concentrations of alkaloids from the insects are captured and stored in the frogs’ skin, which makes the frog toxic to any predator that might try to eat it. Interestingly, 13 of the toxic compounds present in the painted mantella’s skin are also found in the skin of dart frogs, even though the species are continents apart and are not related.

Behavior

Like other mantella frogs, the painted mantella is active during the day and moves through vegetation on the forest floor foraging for food. Because they spend their time on the ground and rarely swim, they do not have webbed toes, and their legs are shorter in proportion than those of other frog species, which helps them climb over debris like branches.

Reproduction and Life Cycle

Males call from refuges under grass, bushes, and rocks to announce their territory and attract females, using rapid, short clicking sounds. These frogs do not demonstrate amplexus, in which the male grasps the female around the back and holds on to mate. Instead, during the first heavy spring rains the female lays up to 130 eggs on the ground or in leaf litter, and then the male fertilizes them with sperm. The eggs develop while still on land for only a few days, and then the tadpoles hatch when rain washes them into a nearby body of water. They then grow into froglets, feeding on algae for six to eight weeks. They are mature at about one year of age.

Conservation and Threats

The painted mantella is currently listed as a species of Least Concern because it occupies a fairly large range, is thought to have high population densities, and occurs in several protected areas, including national parks. However, deforestation to make room for housing and agriculture is a threat. In addition, chytrid fungus has been found in Madagascar, and this disease is a serious concern for all frog species.