Dr. Clive Cummins
November 1998
Last
update: 17 August, 2002
In an article entitled Cannibalistic interactions resulting from indiscriminate predatory behavior in tadpoles of poison frogs (Anura: Dendrobatidae) (Biotropica, 1998, Vol. 30, pp. 92-103), J.P. Caldwell & M.C. de Araujo describes a study of a population of Dendrobates castaneoticus in lowland rainforest in Para, Brazil, with additional data from D. auratus in Nicaragua. At the study site in Brazil they established a grid of 40 Brazil nut capsules, in which D. castaneoticus deposited tadpoles. Of 42 tadpoles deposited during the 55 days of the study, 20 were killed or died; 16 of these were presumed killed by conspecific tadpoles. |
Growth rate and time to metamorphose were higher among tadpoles that consumed three or more tadpoles or relatively large larvae of the mosquito Trichoprosopon digitatum, a colonist of newly-opened Brazil nut capsules. The authors proposed that selection has favoured the development of predatory behaviour in Dendrobatid tadpoles primarily as a mechanism to eliminate predators from the small pools in which they develop, and that cannibalism is a secondary outcome of this behaviour.