Red Backed Poison Frog, Ranitomeya reticulata

The Red backed Poison Frog (Ranitomeya reticulata) is a species of frog belonging to the family Dendrobatidae. It’s an arboreal insectivorous species, and is the second most poisonous species in the genus, after R. variabilis. Like many species of small poisonous frogs native to South America, it’s grouped with the poison dart frogs, and is a moderately toxic species, containing poison that is capable of causing serious injury to humans, and death in animals such as chickens. This frog is native to Peru and Ecuador.

Its toxins are utilized as the frog’s natural defense mechanisms, making them inedible to many, if not most, of the predators in its natural area. To advertise its poison and to further reduce the risk of injury, the red backed poison frog displays its brilliant warning colors, especially its red-orange back, for which it is named. Like all dendrobatids, it doesn’t manufacture the poison itself, but rather is theorized to take the toxins from the ants, mites, and beetles on which it lives. It absorbs the insects; poison into its body, which is immune. The poison is stored in the skin glands that are just beneath the frogs epidermis. The poison seeps through open wounds and orifices, and, it is believed, through its pores. This defense is particularly effective against mammalian and avian predators, and, to a lesser extent, reptilian ones. Amazonian ground snakes have a limited resistance to the poison, and occasionally will attack such frogs.

This frog is one of the smaller species of poison dart frogs, hence its inclusion in the “thumbnail” species group. The males can reach about twelve millimeters in length from snout to vent, while the larger females may reach 15 to even 20 millimeters long. Like all poison dart frogs, these frogs are vividly colored and patterned, which advertises their poison. The red backed poison dart frogs have black legs with a cobalt or sky blue colored mesh pattern, a black belly, and a back that ranges from fiery orange to scarlet in color, hence its common name. Like all arboreal frogs, R. reticulata possess sucker like disks on their toes which makes their grip adhesive. As they are of very small size, they often attempt to advertise their poison by flaunting such colors or by ascending trees to escape from their predators. If isolated from any form of escape, this frog will use their poison as a defense mechanism. R. reticulata are more slimly built than many dendrobatids, which combined with their small size, gives them the ability to squeeze into small hiding places.

It naturally lives in groups of five or six. At the end of the wet season, several of these groups join in large breeding cluster. As with other poison dart frogs, the males court the females by calling to capture their attention, and then by gently licking and stroking them. A female will signal that she is sufficiently impressed by stamping her hind feet and the two frogs will then begin to mate.

The fact that the breeding season begins at the end of the wet season ensures that the eggs will be laid at the beginning of the next wet season, making sure that the young will have a steady supply of water to keep them alive. Once the eggs hatch, the male will carry the baby tadpoles into the canopy. The tadpoles have a water-soluble adhesive mucus that assists them in sticking to their fathers back. The male individual will deposit the tadpoles into the tiny pools that build up in the center of bromeliads. The female will then feed the tadpoles with infertile eggs that she lays in the water. Once the tadpoles become froglets, they are led by the parents to an existing group of red backed poison frogs. While the young froglets are accepted by all of the members of the group, only their parents will look after the young frogs.

Image Caption: Wild specimen of the arrow-poison frog, Dendrobates reticulatus; easternmost Peru, near Amazon River. Credit: Tim Ross/Wikipedia