Life history of frogs of the Brazilian semi-arid (Caatinga), with emphasis in aestivation

The semi-arid region (caatinga), that corresponds to 18.26% (1,540,000 km2) of Brazil, occupies most the northeast region. Rainfall is irregular and concentrated within the first 3 months of the year. Prolonged periods of drought, with low total rainfall, may extend for two or more years. Most of the rivers of this biome are temporary, remaining totally dry during periods of drought. We collected and observed the natural history and biology of the species Proceratophrys cristiceps, Pleurodema diplolister and Physalaemus spp, both in the rainy and dry seasons, in ten field expeditions to the State of Rio Grande do Norte (Brazil). We focused on the morphology of the skin and cutaneous glands, specifically in their defence against desiccation. During the dry season, they form concentrations in the bed of temporary rivers, burrowing themselves in favourable locations within the sand, at depths that may exceed 1.50 m. No morphological evidence was found that there are specific cutaneous adaptations against water loss. We suggest that the cutaneous fragility per se is a cutaneous adaptation to water balance. The behaviour of such anuran species, together with their physiological characteristics, should be the main tools to face the challenge of living in xeric conditions.

A taxonomic review of the genus Hemiphractus (Anura: Hemiphractidae) in Panama: Description of Two New Species, Resurrection of Hemiphractus panamensis (Stejneger, 1917), and Discussion of Hemiphractus fasciatus Peters, 1862.

We reviewed the taxonomic status of populations of frogs in the genus Hemiphractus in Panama, which have all been referred to Hemiphractus fasciatus Peters, 1862 for over 40 years. Although relatively few specimens have been collected, mostly juveniles, it is clear that these frogs inhabit three separate upland regions of the country: The Cordillera de Talamanca in western Panama, the Chagres Highlands and Cordillera de San Blas in central Panama, and the Serranía de Pirre in the far eastern portion of the country. In accordance with previously published molecular data, we identified distinctive features of the skulls of frogs representing these three allopatric populations and herein revalidate H. panamensis (Stejneger, 1917), describe the new species Hemiphractus elioti sp. nov. from the Cordillera de Talamanca, and the new species Hemiphractus kaylockae sp. nov. from the Serranía de Pirre. We also propose that the taxon H. fasciatus is a South American species not occurring in Panama.

A review of the biology and literature of the Gulf Coast Toad (Incilius nebulifer), native to Mexico and the United States.

The Gulf Coast Toad (Incilius nebulifer) is an abundant and widespread species within its range in the United States and Mexico, so it appears on many faunal checklists and is considered in diverse kinds of research. We review the basic biology, distribution, and published history of this species, identifying only those records and publications referable to I. nebulifer, to help researchers identify published works pertaining to I. nebulfer rather than I. valliceps, with which it formerly was considered to be conspecific.

Riding the wave: reconciling the roles of disease and climate change in amphibian declines.

We review the evidence for the role of climate change in triggering disease outbreaks of chytridiomycosis, an emerging infectious disease of amphibians. Both climatic anomalies and disease-related extirpations are recent phenomena, and effects of both are especially noticeable at high elevations in tropical areas, making it difficult to determine whether they are operating separately or synergistically. We compiled reports of amphibian declines from Lower Central America and Andean South America to create maps and statistical models to test our hypothesis of spatiotemporal spread of the pathogen Batrachochytrium dendrobatidis (Bd), and to update the elevational patterns of decline in frogs belonging to the genus Atelopus. We evaluated claims of climate change influencing the spread of Bd by including error into estimates of the relationship between air temperature and last year observed. Available data support the hypothesis of multiple introductions of this invasive pathogen into South America and subsequent spread along the primary Andean cordilleras. Additional analyses found no evidence to support the hypothesis that climate change has been driving outbreaks of amphibian chytridiomycosis, as has been posited in the climate-linked epidemic hypothesis. Future studies should increase retrospective surveys of museum specimens from throughout the Andes and should study the landscape genetics of Bd to map fine-scale patterns of geographic spread to identify transmission routes and processes.