|Black-legged poison dart frog|
|Binomial name||Phyllobates bicolor|
|Average Size||4.75-5.5 cm (1.9-2.2 in)|
|Average weight||6-9 grams|
|Distribution of species||Southern Colombia|
The black-legged poison dart frog, Phyllobates bicolor, is a species of poison dart frog endemic to western Colombia. It is the second-most toxic of the poison dart frogs after the closely related, and morphologically similar, P. terribilis. It lives in the lowland forests in the Chocó area in western Colombia, along the San Juan river, although some populations lives further south in Quebtada Guangui.
Along with P. terribilis and P. sp. aff. aurotaenia, the black-legged poison dart frog is one of the few poison dart frogs to primarily secrete batrachotoxins through its skin. While its toxicity is weaker than P. terribilis, Phyllobates bicolor is still a highly toxic animal, one of the few frogs confirmed to have caused human fatalities. Just 15 micrograms of its poison is enough to kill an adult human. This frog is often heated over a flame to make it "sweat" the liquid poison for hunting darts. The poison causes death by respiratory and muscular paralysis. As with all dart frogs, captive-raised individuals are not toxic; the animals require chemicals found only in their wild food sources, mainly insects. In captivity, these chemicals are not available to them from their food source.
Phyllobates bicolor can be extremely difficult to differentiate from P. terribilis. One way of differentiating the two species is that black-legged poison dart frogs are generally smaller than golden poison dart frogs. Males can reach approximately 5 cm (2 in) long, whereas the larger females may reach 5.5 cm (2.2 in) long. They are also more slimline than golden poison dart frogs, which are larger and heavily muscled.
Phyllobates bicolor are usually coloured similarly to P. terribilis. Their primary colour ranges from earthy orange to pure yellow. The limbs and belly are flecked with black- this is one of the best ways to differentiate the two species, as the golden poison dart frog lacks these black flecks.
Along with the golden poison dart frog, the black-legged poison dart frog is more arboreal than many dendrobatids. As a result, it possesses suckerlike discs on its toes in order to aid it in climbing of tree trunks and leaves. It has an adhesive grip, but unlike Dendrobates tinctorius and azureus, the size and shape of the toe discs do not vary between the sexes. Both sexes have oval-shaped toe discs rather than heart-shaped in males and circular in females.
The black-legged poison dart frog is one of the most intelligent anurans known. It can distinguish between humans, and it is capable of remembering locations that suit it well weeks after visiting them. P. bicolor, like most poison dart frogs, lives in small groups of four to seven with an average of four; captive bicolor can be kept in smaller or larger groups than that. Like many poison dart frogs, bicolor groups are territorial and will attempt to fend off rival groups by calling.
Groups of black-legged poison dart frogs gather to breed. Males are vocal and will call to females with a pleasing trill. Once a male catches the attention of a male, he courts her by gently carressing her body. If she is sufficiently impressed, she will allow the male to lead her to a suitable place for egg deposition. Amplexus takes place on the ground or on low-growing plants, and fertilization is external. The clutch size ranges from five to twelve eggs.
Like all members of its species group, Phyllobates bicolor have duel parental care. The eggs are laid between 1.2 and 1.5 metres from the ground, and are guarded by both parents. They are typically laid in shady areas where the air is moister. When the eggs hatch, they squirm into a tight ball around their parents. They are transported to water-filled tree hollows, where they complete their development while being guarded by either parent.
Phyllobates bicolor is one of the easiest poison dart frogs to keep but requires a fairly large vivarium due to the fact that it is very large for a poison dart frog. Unlike most poison dart frogs, it needs a relatively constant humidity. Most dendrobatids require a high humidity, but how high their humidity is can vary from 80%-95%. P. bicolor, on the other hand, has a very limited distribution and the humidity there is usually 85-90%. An automated misting system is usually the best way to provide humidity for black-legged poison dart frogs.
Black-legged poison dart frogs can also be overheated. The optimal temperature range for P. bicolor is 23-28 degrees Celsius. 40 or 60-watt light bulbs are usually sufficient for heating.
The feeding and breeding of this species is similar to the closely related golden poison dart frog.