Maternally derived chemical defences are an effective deterrent against some predators of poison frog tadpoles ( Oophaga pumilio )

Abstract

Parents defend their young in many ways, including provisioning chemical defences. Recent work in a poison frog system offers the first example of an animal that provisions its young with alkaloids after hatching or birth rather than before. But it is not yet known whether maternally derived alkaloids are an effective defence against offspring predators. We identified the predators of Oophaga pumilio tadpoles and conducted laboratory and field choice tests to determine whether predators are deterred by alkaloids in tadpoles. We found that snakes, spiders and beetle larvae are common predators of O. pumilio tadpoles. Snakes were not deterred by alkaloids in tadpoles. However, spiders were less likely to consume mother-fed O. pumilio tadpoles than either alkaloid-free tadpoles of the red-eyed treefrog, Agalychnis callidryas , or alkaloid-free O. pumilio tadpoles that had been hand-fed with A. callidryas eggs. Thus, maternally derived alkaloids reduce the risk of predation for tadpoles, but only against some predators.

New observations of frog and lizard predation by wandering and orb-weaver spiders in Costa Rica

“…with its front legs, it immediately rejected the observation is consistent with previous experiments in which attacked and then rejected (Szelistowski 1985, Stynoski 2014, Murray 2016. It is likely that the spiders evaluate dendrobatid chemical cues received during contact and deem them unpalatable (Murray 2016; but see Summers 1999).…”

Variable Alkaloid Defenses in the Dendrobatid Poison Frog Oophaga pumilio are Perceived as Differences in Palatability to Arthropods

“…Alkaloid defenses of O. pumilio are also known to vary within populations (Daly et al 1994;Saporito et al 2010aSaporito et al , 2012Stynoski et al 2014aStynoski et al , 2014b, and in the current study, differences in alkaloid defenses and palatability were observed between sexes and life stages for one population. Assays with the ant, E. ruidum at La Selva, Costa Rica found differences in palatability that were largely attributed to differences in alkaloid quantity.…”

Evolutionary constraints of warning signals: A genetic trade-off between the efficacy of larval and adult warning coloration can maintain variation in signal expression

“…; Stynoski et al. ; Umbers and Mappes ). If color elements of larval and adult warning coloration are genetically correlated, variation expressed in adult coloration could be maintained not only via direct responses to selection on color traits in adults but also through indirect responses of selection on larval coloration and vice versa.…”