-- the poison dart frogs
In the American tropics lives a
group of small, diurnal frogs named for the alkaloid skin secretions
protecting most species. In some members, especially Phyllobates
terribilis, these toxins are highly potent and are reputedly
used by Chocó Indians in Colombia to treat hunting darts.
To date well over a hundred species have been placed in the three
genera comprising the Dendrobatidae. Despite their tiny size
(the largest species barely reaches two inches in length) their
brilliant coloration makes most species conspicuous as they spring
about the forest floor, actively searching out the ants that
make up the bulk of their diet. Dendrobatids lay their eggs on
land, where they are guarded by an adult, most frequently the
male, who carries the newly hatched tadpoles to water.
Spot-Bellied Dart Frog
In the jungle of
the upper Amazon basin the poison frog genus Dentrobates
is represented by a complex of red or yellow and black frogs
currently classified as one, two or three species, but the systematics
of this group are confusing, and could very nicely stand revision.
Despite the variety exhibited in both color patterns and sundry
nuances in their buzzing calls, the habits of this complex don't
appear to vary greatly. Two or three eggs are usually deposited
on land and guarded by an adult. Upon hatching, the tadpoles
wriggle onto the attendant parent's back, to be hauled up a tree
trunk and deposited into bromeliad vacuoles, where they are left
to develop. The female regularly lays an infertile egg for each
tadpole to eat. Unlike some other dendrobatid species, the D.
ventrimaculatus tadpole is not an exclusive egg feeder,
but also eats algae and mosquito larvae. The form depicted in
this piece was given species status and named D. duellmani
after William Duellman in 1999.