Predator perception of aposematic and cryptic color morphs in two Oophaga species.

Animals that are toxic often advertise their unprofitability to potential predators through bright aposematic colors while cryptic ones blend in with their natural background to avoid predators. In the poison dart frogs, Oophaga pumilio and O. granulifera, some populations in Costa Rica and Panama display cryptic green and aposematic red color morphs. We herein used reflectance spectra from the dorsum of red and green morphs of these frogs to estimate their perception by the visual systems of three potential predators (birds, lizards, and crabs) against three natural backgrounds (leaves, trunks and leaf litter). Statistical analyses revealed no strong differences in color contrast against backgrounds between the two frog species. However, strong effects of frog morph, predator, background, and their interactions were observed. When viewed against diverse backgrounds, red frogs of both Oophaga species are more color conspicuous to birds and Anoline lizards than to crabs. A strong effect of species was observed on luminance contrast. Concerning the latter, green frogs particularly in O. granulifera appear more conspicuous than red frogs, while birds perceive higher brightness contrasts than lizards or crabs. Our results further support the importance of birds and lizards as Oophaga predators and provide a first quantitative comparison of conspicuousness between these two frog species.

Mantzana-Oikonomaki V ，Rodríguez A ，Castillo-Tamayo G ，Ibáñez R ，Pröhl H ... -  《Ecology and Evolution》

An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species.

Dreher CE ，Cummings ME ，Pröhl H 《PLoS One》

Interspecific and intraspecific views of color signals in the strawberry poison frog Dendrobates pumilio.

Siddiqi A ，Cronin TW ，Loew ER ，Vorobyev M ，Summers K ... -  《JOURNAL OF EXPERIMENTAL BIOLOGY》

Not everything is black and white: color and behavioral variation reveal a continuum between cryptic and aposematic strategies in a polymorphic poison frog.

Aposematism and crypsis are often viewed as two extremes of a continuum of visual conspicuousness to predators. Theory predicts that behavioral and coloration conspicuousness should vary in tandem along the conspicuousness spectrum for antipredator strategies to be effective. Here we used visual modeling of contrast and behavioral observations to examine the conspicuousness of four populations of the granular poison frog, Oophaga granulifera, which exhibits almost continuous variation in dorsal color. The patterns of geographic variation in color, visual contrast, and behavior support a gradient of overall conspicuousness along the distribution of O. granulifera. Red and green populations, at the extremes of the color distribution, differ in all elements of color, contrast, and behavior, strongly reflecting aposematic and cryptic strategies. However, there is no smooth cline in any elements of behavior or coloration between the two extremes. Instead populations of intermediate colors attain intermediate conspicuousness by displaying different combinations of aposematic and cryptic traits. We argue that coloration divergence among populations may be linked to the evolution of a gradient of strategies to balance the costs of detection by predators and the benefits of learned aversion.

Willink B ，Brenes-Mora E ，Bolaños F ，Pröhl H ... -  《-》

Being red, blue and green: the genetic basis of coloration differences in the strawberry poison frog (Oophaga pumilio).

Rodríguez A ，Mundy NI ，Ibáñez R ，Pröhl H ... -  《BMC GENOMICS》