Apparent Decline of the Golden Toad: Underground or Extinct?

The cause of global amphibian declines: a developmental endocrinologist's perspective

“…This observation may seem to state the obvious, but it is important to point it out. Many population declines have received attention because adults simply disappeared rapidly and/or massive die-offs were documented (Crump et al, 1992;Pounds and Crump, 1994). Just because adults are present at a locality and massive deaths are not observed in a population does not mean that a given population is not in decline.…”

Coincident mass extirpation of neotropical amphibians with the emergence of the infectious fungal pathogen Batrachochytrium dendrobatidis

“…Establishing the presence of Bd in museum specimens from vanished populations could be the key to uncovering the historical and geographical spread of this pathogen and would provide objective evidence of Bd emergence and subsequent Bd-driven amphibian decline. In this study, we use noninvasive sampling and molecular techniques to detect Bd in formalin-preserved specimens to investigate the role of Bd in two well-studied cases of enigmatic amphibian decline in Mesoamerica (i): the decline and disappearance of anurans from Costa Rica's Monteverde Reserve in the late 1980s (13,14), and (ii) the decline and disappearance of plethodontid salamanders from the mountains of southern Mexico and western Guatemala in the 1970s and 1980s (15).…”

“…The sudden extinction of the golden toad (Bufo periglenes) and harlequin frog (Atelopus varius) from Costa Rica's Monteverde Reserve in the late 1980s (13,14) are among the earliest and best-documented cases of enigmatic declines that have come to characterize the global amphibian crisis. The subsequent disappearance of 40% (20/49 species) of anurans from Monteverde's cloud forest (16) places the Monteverde declines among the most extreme cases of documented biodiversity loss in amphibian faunas.…”

“…The subsequent disappearance of 40% (20/49 species) of anurans from Monteverde's cloud forest (16) places the Monteverde declines among the most extreme cases of documented biodiversity loss in amphibian faunas. Various hypotheses have arisen regarding the cause of this decline, including the arrival of Bd to naïve amphibian populations in Monteverde as part of a southward-moving Bd wave (7) and climate-linked Bd emergence (13,16,17), with implications for worldwide Bd emergence. Remarkably, despite the central role that Bd has been hypothesized to play in these declines, no direct evidence has been reported of Bd emergence in Monteverde coincident with declines.…”

Anuran Amphibians: A Huge and Threatened Factory of a Variety of Active Peptides with Potential Nanobiotechnological Applications in the Face of Amphibian Decline

“…Several long-term studies performed on intact natural ecosystems such as Yellowstone National Park and Sierra Nevada of California in United States (Noss et al, 2002;Vredenburg et al, 2007), Eungella National Park in Australia (McDonald, 1990), and Monteverde Cloud Forest Preserve in Costa Rica (Pounds et al, 1997) show a worldwide decline in amphibian species in the last two decades. Populations of many species of frogs have declined dramatically in relatively undisturbed habitats at high altitudes and anthropized areas throughout the world (Blaustein & Wake, 1990, 1995Blaustein et al, 1994;Bradford, 1991;Campbell, 1999;Carey, 1993;Collins & Storfer 2003;Crump et al, 1992;Czechura & Ingram, 1990;Hero et al, 2005;Kiesecker et al, 2001;McDonald, 1990;McMenamin et al, 2008;Pounds, 2001;Reading, 2007;Richards et al, 1993;Skerratt et al, 2007;Stuart et al, 2004;Young et al, 2001). A map produced by IUCN shows the global distribution of threatened amphibians (Figure 2) revealing that the greatest concentration of threatened amphibian are in relatively limited areas dominated by species living within specific ranges, often living in mountainous areas.…”