Renewing hope: the rediscovery of Atelopus varius in Costa Rica

Abstract

bstract. More than 90% of harlequin frog species (Atelopus spp.), endemic to the Americas, are currently threatened with extinction. We report the discovery of the only currently known hreeding population of the Critically Endangered/4. varius in Costa Rica. This population was located in 2008 on a private property in Las Tablas Protected Zone near San Vito, Coto Brus at 1300 m elevation. Previously, the only known remaining/remnant population of this species and genus was a single location near Manuel Antonio, Puntarenas, Costa Rica, where two individuals were documented in 2004. Subsequent searches at this location have yielded no additional sightings. Delineating the spatial limits of this population, quantifying demographics and resource use, and implementing conservation actions are necessary to ensure persistence of this population. Conducting additional surveys in this region to ascertain occurrence of additional populations is warranted.

Infection with Batrachochytrium dendrobatidis is common in tropical lowland habitats: Implications for amphibian conservation

“…SDMs can help identify hotspots for future outbreaks of Bd and can be used to predict potential locations for amphibian rediscoveries (García-Rodríguez et al, 2012;Puschendorf et al, 2009). Recent validation surveys have led to the discovery of relict peripheral populations that occur in potential environmental refuges from disease Raffel & Fox, 2018;Scheele, Hunter, Skerratt, Brannelly, & Driscoll, 2015), validating increased surveys outside the boundaries of core geographic distributions (Abarca, Chaves, García-Rodríguez, & Vargas, 2010;Chaves et al, 2014;González-Maya et al, 2013;Jiménez & Alvarado, 2017;Nishida, 2006). A comprehensive assessment of a pathogen's distribution, prevalence, and infection intensity can lead to more effective disease-management strategies based on specific locations, habitats, and species.…”

Prevalence of the fungal pathogenBatrachochytrium dendrobatidisin amphibians of Costa Rica predated first-known epizootic

“…The steady increase in prevalence of Bd throughout all elevations in Costa Rica after 1990 suggests that Bd has become more broadly established throughout the country [25,75] than it was previously. The recent rediscovery of some remnant populations of frogs once thought extinct provides new opportunities to assess the current impact of Bd in highly susceptible species [25,29,30,32]. Consistent with previous studies, we propose that Bd epizootics in amphibians began in the central range of Costa Rica, affecting stream-breeding and pond-breeding species that inhabited this region (supplementary tables 1 and 2) such as Lithobates vibicarius, Isthmohyla angustilineata, I. tica, I. xanthosticta, I. rivularis, Duellmanohyla uranochroa Craugastor fleischmanni, C. ranoides, C. escoces, C. sp.…”

“…[28], and yet decades later they appear to be slowly recovering from past Bd epizootics [25,29,30]. Similar cases of catastrophic decline followed by apparent recovery have been observed in some highland populations of harlequin frogs, tree frogs and ranid frogs [31,32]. Population fluctuations such as these elicit questions regarding the role of Bd transmission, virulence, and lineage in this disease system.…”

Potential effect of habitat disturbance on reproduction of the critically endangered harlequin frog Atelopus varius in Las Tablas, Costa Rica

“…Despite this decline, Atelopus varius is one of the few harlequin frog species remaining in Central America. Reproductive populations have recently been recorded in Costa Rica and Panama (González-Maya et al, 2013;Perez et al, 2014;Barrio-Amorós and Abarca, 2016), providing the opportunity to carry out research and conservation efforts to better understand the factors leading to the decline and how to address them.…”