Hyla gratiosa

Number of Pages: 2Integrative BiologyGeological Science

Escape responses of cryptic frogs (Anura: Brachycephalidae: Craugastor) to simulated terrestrial and aerial predators

Summary Cryptic prey may increase likelihood of being detected if they move. When approached by predators, they must assess probabilities of survival if they remain immobile or attempt escape. Probability of survival is the joint probability of being detected, attacked if detected, and captured if attacked. We studied escape responses of several species of cryptic Craugastor (= Eleutherodactylus) frogs to simulated ground and aerial predators by varying elevation angle of attack. Frogs were predicted to escape more frequently when attacked from higher angles because a predator attacking from above on a trajectory leading directly to the prey is more likely to have detected and be attacking than a predator approaching directly, but horizontally. Frogs approached horizontally rarely jumped. The proportion of frogs that jumped increased as attack angle increased, and the proportion that turned or twitched was greatest for 45 • approaches. Distance jumped did not vary among attack angles. Escape was directed away from the object approaching at 45 • , but was random with respect to the frog's orientation during vertical approaches. Variation in escape tendency may occur because risk increases as attack angle increases, possibly because risk of being detected from above is greater and/or aerial predators are more efficient

Amazonian Amphibian Diversity Is Primarily Derived from Late Miocene Andean Lineages

The Neotropics contains half of remaining rainforests and Earth's largest reservoir of amphibian biodiversity. However, determinants of Neotropical biodiversity (i.e., vicariance, dispersals, extinctions, and radiations) earlier than the Quaternary are largely unstudied. Using a novel method of ancestral area reconstruction and relaxed Bayesian clock analyses, we reconstructed the biogeography of the poison frog clade (Dendrobatidae). We rejected an Amazonian center-of-origin in favor of a complex connectivity model expanding over the Neotropics. We inferred 14 dispersals into and 18 out of Amazonia to adjacent regions; the Andes were the major source of dispersals into Amazonia. We found three episodes of lineage dispersal with two interleaved periods of vicariant events between South and Central America. During the late Miocene, Amazonian, and Central American-Chocoan lineages significantly increased their diversity compared to the Andean and Guianan-Venezuelan-Brazilian Shield counterparts. Significant percentage of dendrobatid diversity in Amazonia and Chocó resulted from repeated immigrations, with radiations at <10.0 million years ago (MYA), rather than in situ diversification. In contrast, the Andes, Venezuelan Highlands, and Guiana Shield have undergone extended in situ diversification at near constant rate since the Oligocene. The effects of Miocene paleogeographic events on Neotropical diversification dynamics provided the framework under which Quaternary patterns of endemism evolved

Allophrynidae, Allophryne, A. ruthveni

Number of Pages: 3Integrative BiologyGeological Science

A new poison frog from Amazonian Brazil : with further revision of the quinquevittatus group of Dendrobates. American Museum novitates ; ; no. 2988.

21 p. : ill. (some col.) ; 26 cm.Includes bibliographical references (p. 20-21

A new amazonian species of Colostethus with sky blue digits

We describe a new species of Colostethus that is unusual in that males have blue digits on the hands and blue toe discs; females have blue discs on the fingers and toes but lack blue digits. The new species occurs in lowland tropical rainforest south of Manaus, Amazonas, Brazil, in the municipality of Castanho, at km 12 on the road to Autazes. Six species of Colostethus occur in the vicinity of Manaus; two, C. stepheni and C. marchesianus, occur north of the Amazon River, and four, including the new species and three undescribed species, occur south of the river. Four of these six species have small body size; i.e., adult male SVLs are ≤18.0 mm. Two of the species, both undescribed, from south of the Amazon have adult male SVLs ≥19.5 mm. Calls of all six species are unique; calls are produced either continuously, as inthe case of the new species, C. marchesianus, and one of the large undescribed species south of the Amazon river, or in bouts of varying lengths. The function of the blue digits in males of the new species is unknown but may be associated with visual communication during reproductive behavior. Blue toes or discs were present only in adults during the breeding season

A New Amazonian Species of Colostethus (Anura Dendrobatidae) with a Nidicolous tadpole.

We describe adults, tadpoles, and vocalization of a new Amazonian species of Colostethus from a terra firme rainforest locality south of the Amazon River near Manaus, Amazonas, Brazil. This species is characterized by the absence of dorsolateral and ventrolateral stripes, the presence of a short, diffuse oblique lateral stripe, Finger III of male not swollen, and the presence of a black or gray throat in the male. In addition, the new species is larger than three other species in the Amazon region (C. caeruleodactylus, C. marchesianus, and C. stepheni) and its call, typically composed of long bouts of continuous notes, is distinct from these three species. This species is the fourth known Colostethus with an endotrophic tadpole; in three of these species, including C. nidicola, eggs are deposited and develop entirely in a terrestrial nest. Clutches of C. nidicola are composed of about three eggs and are placed in leaf litter on the forest floor. Whether C. nidicola is closely related to any of the other three species with endotrophic tadpoles is unknown at present. A phylogenetic analysis of this group of frogs will be necessary to detect whether endotrophy has evolved once or multiple times. Examination of tadpoles of C. nidicola and comparisons with characters reported for the other three species that have endotropic tadpoles revealed that tadpoles within each species have unique combinations of characters or loss of characters. Endotrophic tadpoles have not been reported for any other dendrobatids