Red-backed Poison Frog
The Red-backed Poison Frog (Ranitomeya reticulatus) is a species of frog in the family Dendrobatidae. It is 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 is grouped with the poison dart frogs, and is a moderately toxic species, containing poison capable of causing serious injury to humans, and death in animals such as chickens. R. reticulatus is endemic to Peru.
The red-backed poison frog is a moderately toxic dendrobatid, and is the second-most poisonous of the frogs in the Ranitomeya genus, after the splash-backed poison frog. Its toxins are used 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 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 does not manufacture its poison itself, but rather takes the toxins from the Amazonian fire ants on which it lives. It absorbs the ants' neurotoxic venom into its body, which is immune to the poison. The poison is stored in skin glands just beneath the frog's epidermis. The poison seeps through open wounds and orifices, and, it is believed, through the pores. This defense is especially 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.
Ranitomeya reticulatus is one of the smaller species of poison dart frogs, hence its inclusion in the "thumbnail" species group. Males can reach approximately 12 mm in length from snout to vent, while the larger females may reach 15 or even 20 mm long. Like all poison dart frogs, R. reticulatus are vividly coloured and patterned, which advertises their poison. Red-backed poison dart frogs have black legs with a cobalt or sky-blue mesh pattern, a black belly, and a back that ranges from fiery orange to scarlet in color, hence the common name. Like all arboreal frogs, reticulatus possess suckerlike disks on their toes which makes their grip adhesive. As they are very small, they often attempt to advertise their poison by flaunting such colors or by ascending trees to escape from predators. If isolated from any form of escape, reticulatus will use their poison as a defense mechanism. Reticulatus are more slimly built than many dendrobatids, which combined with their small size, gives them the ability to squeeze into minute hiding places.
R. reticulatus naturally live in groups of five or six. At the end of the wet season, several of these groups join in large breeding gatherings. As with other poison dart frogs, the males court the females by calling to capture their attention, and then by gently stroking and licking them. A female will signal that she is sufficiently impressed by stamping her hind feet. The two frogs will then mate. The fact that the breeding season begins at the end of the wet season ensures that the eggs will be layed at the beginning of the next wet season, ensuring that the young will have a steady supply of water to keep them alive. Once the eggs hatch, the male carries the baby tadpoles into the canopy. The tadpoles have a water-soluable adhesive mucus that helps them stick to their father's back. The male reticulatus will deposit the tadpoles into the tiny pools that accumulate in the centre of bromeliads. The female will then feed the tadpoles with infertile eggs that she lays into the water. Once the tadpoles become froglets, they are led by their parents to an existing group of red-backed poison frogs. While the young froglets are accepted by all members of the group, only their parents will look after the young frogs.
R. reticulatus is a difficult poison dart frog to keep due to its small size. Although small, it requires a sizeable terrarium due to its areboreal nature.