Evidence for individual vocal recognition in a pair-bonding poison frog, Ranitomeya imitator.

Individually distinctive vocalizations are widespread in nature, although the ability of receivers to discriminate these signals has only been explored through limited taxonomic and social lenses. Here, we asked whether anuran advertisement calls, typically studied for their role in territory defense and mate attraction, facilitate recognition and preferential association with partners in a pair-bonding poison frog (Ranitomeya imitator). Combining no- and two-stimulus choice playback experiments, we evaluated behavioral responses of females to male acoustic stimuli. Virgin females oriented to and approached speakers broadcasting male calls independent of caller identity, implying that females are generally attracted to male acoustic stimuli outside the context of a pair bond. When pair-bonded females were presented with calls of a mate and a stranger, they showed significant preference for calls of their mate. Moreover, behavioral responses varied with breeding status: females with eggs were faster to approach stimuli than females that were pair bonded but did not currently have eggs. Our study suggests a potential role for individual vocal recognition in the formation and maintenance of pair bonds in a poison frog and raises new questions about how acoustic signals are perceived in the context of monogamy and biparental care.

Large, old trees define the vertical, horizontal, and seasonal distributions of a poison frog.

In tropical forests, large, old trees (LOTs) can be considered keystone structures for provisioning unique habitats such as decaying wood, roots, cavities, and epiphytes, including those that hold water (phytotelmata). These habitats may also be stratified in vertical space, for example, root structures occur at ground level and below, whereas epiphytes occur above-ground. Canopy habitat is utilized by a diversity of amphibians, but canopy habitat may only be viable in the wet season when epiphytes and surfaces are sufficiently saturated. Here, we examine how the provisioning of microhabitats and structures by LOTs influence the horizontal, vertical, and seasonal distribution patterns of phytotelmata-breeding poison frogs. We conducted ground-to-canopy surveys over 4 years, constituting 6 seasons, in Panama and used mark-recapture techniques on a population of the yellow-bellied poison frog, Andinobates fulguritus. We found that A. fulguritus migrated vertically, tracking seasonal rainfall, and displayed strong philopatry to individual trees. Furthermore, A. fulguritus almost exclusively inhabited the largest trees at the study location, which provided disproportionately high-quality microhabitats and epiphytes compared to other trees. LOTs, and specifically Anacardium excelsum at our site, appear to serve as keystone structures with high conservation value due to their provisioning of unique habitats. We conclude that the distribution of A. fulguritus is defined vertically by the stratification of arboreal microhabitat resources, horizontally by the presence of LOTs providing the resources, and temporally by the seasonal viability of the resources.

Experimental evidence for maternal provisioning of alkaloid defenses in a dendrobatid frog.

Dendrobatid frogs sequester alkaloid defenses from dietary arthropods. Here, we provide experimental evidence that mother strawberry poison frogs (Oophaga pumilio) provision alkaloids to tadpoles. Captive-raised females were fed the synthetic alkaloid decahydroquinoline (DHQ), which we subsequently quantified in their skin, eggs, and developing tadpoles. DHQ quantity was positively associated with tadpole mass/development, suggesting high sequestration rates by tadpoles. These data confirm that tadpoles obtain nutrition and alkaloids by feeding exclusively on maternally provisioned eggs.

Systematics of the Ameerega rubriventris complex (Anura: Dendrobatidae) with descriptions of two new cryptic species from the East-Andean versant of Peru.

We describe two new species of poison frog from central and southern Peru that have been referred to as Ameerega picta, A. hahneli, or A. altamazonica throughout the past thirty years. Our phylogenies generated with genomic data provide strong support that the two new species are successive sisters to two described taxa, A. rubriventris and A. altamazonica, and collectively comprise the Ameerega rubriventris complex. The first new taxon, Ameerega panguana sp. nov., can be distinguished from all other Ameerega by its combination of a unique white venter and an advertisement call of 1-2 notes per second. The second new taxon, Ameerega imasmari sp. nov., is the only cryptically colored Ameerega species that is disttributed across the Fitzcarrald Arch in Southern Peru which possesses a 'peep' advertisement call consisting of 3-4 notes per second and a dominant frequency of 4.3-4.5 kHz. Within the Ameerega rubriventris complex, we observed differences between species in their ventral coloration, tympanum diameter, and call, which suggest that these taxa are reproductively isolated from each other.

Mating status correlates with dorsal brightness in some but not all poison frog populations.

Sexual signals are important for intraspecific communication and mate selection, but their evolution may be driven by both natural and sexual selection, and stochastic processes. Strawberry poison frogs (Oophaga pumilio) show strong color divergence among populations, but coloration also varies among individuals of the same population. The importance of coloration for female mate choice has been studied intensely, and sexual selection seems to affect color divergence in strawberry poison frogs. However, the effect of coloration on mating success under field conditions has received very little attention. Furthermore, few studies examined how phenotypic variation among individuals of the same color morph affects mate selection under natural conditions. We measured the spectral reflectance of courting and noncourting individuals and their background substrates in three geographically separated populations. In one population (Sarapiquí, Costa Rica), we found that naturally occurring courting pairs of males and females had significantly brighter dorsal coloration than individual males and females not engaged in courtship interactions. Our field observations suggest that, in the wild, females prefer brighter males while the reason for the higher courtship activity of brighter females remains unclear. Overall our results imply that brightness differences among individuals of the same color morph may actually affect reproductive success in some populations of strawberry poison frogs.