USGS
Patuxent Home

Accession Number 5004017

Title Incidence and distribution of chytridiomycosis in road-killed amphibians at National

Wildlife Refuges in the Northeast and on Maine routes of the NAAMP

Project Description Within recent decades many populations of amphibians have declined and some species are

probably extinct (e.g., golden toad (Bufo periglenes) in Costa Rica, golden toad and web-footed

coquis (Eleutherodactylus sp.) in Puerto Rico, and gastric-brooding frog (Rheobatrachus spp.) in

Australia (Berger et al. 1999)). In 1991 herpetologists who realized that amphibians were

disappearing in many areas of the world formed the Declining Amphibian Populations Task Force

(DAPTF) to determine the extent and causes of the declines and remedial action needed. The

North American Amphibian Monitoring Program (NAAMP) was a result of the DAPTF efforts.

Deaths of Dendrobates sp. frogs at the National Zoo were diagnosed as caused by cutaneous

chytridiomycosis (Pessier et al. 1999) and the chytrid associated with the dead frogs was isolated

and named Batrachochytrium dendrobatidis (Longcore et al. 1999). The chytrid fungus has been

confirmed as causing death of poison dart frogs (Dendrobates tinctorius) by Kochs postulates

(i.e., isolation of the fungus from infected frogs, experimental exposure of non-infected frogs to

spores of the fungus, then re-isolation of the fungus from dosed frogs that died, while maintaining

control frogs that lived (Longcore et al. 1999). Simultaneously and independently a group of

researchers in Australia U.K., and the United States determined that a chytrid fungus, which is

histologically and morphologically indistinguishable from B. dendrobatidis, was associated with

die-offs in Central America and Australia (Berger et al. 1998, Longcore et al. 1999, Nichols et al.

1998, Pessier et al. 1999). Blaustein and Wake (1995), Laurance et al. (1996, 1997), Daszak et

al. (1999), and Droege (1999) have hypothesized about potential causes of drastic declines of

amphibians and have outlined issues associated with amphibian declines. Although

chytridiomycosis is not the only cause of amphibian mortality and may interact with other

environmental variables, it is an important cause of population declines, as exemplified by its

recent effect on the endangered boreal toad (Bufo boreas) in Colorado (Pollack and Blanchard

1999). The distribution of the Batrachochytrium fungus is primarily known from where it has been

associated with die-offs of amphibians. In this pilot survey (one State), we propose proactive

research to identify the geographical distribution of the fungal pathogen in Maine amphibian

species, primarily frogs. The pathogenic chytrid was isolated in 1999 from 3 species of road-killed

frogs, including 3 northern leopard frogs (Rana pipiens), collected at one site in Maine (J.E.

Longcore, unpubl. data). To collect vehicle-killed specimens throughout Maine, we wish to take

advantage of the sampling framework of the Maine Calling Amphibian Survey (part of the NAAMP)

and efforts by U.S. F&WS personnel (Laura Eaton-Poole, USFWS, pers. commun), who survey

for malformed amphibians on refuges. This study would contribute to Objective 3 of the National

Plan for Amphibian Monitoring and Research (NPAMR) to Develop procedures for collecting

ancillary data during sampling that will facilitate investigation of causes of population declines.,

and it will begin to integrate BRD research studies with monitoring activities to enhance cost

effectiveness through joint efforts.

Keywords acadia national park, amphibians, chytrid fungus, incidence, national wildlife, refuges,

Principal Jerry R Longcore, USGS Patuxent Wildlife Research Center: Jerry_Longcore@usgs.gov; Joyce E

Investigators Longcore, University of Maine: Longcore@maine.maine.edu; Allan P Pessier, Dept. of Pathology,

Zoological Society of San Diego: Apessier@sandiegozoo.org;

Navigate PWRC SIS projects by Accession Number: First Previous Next Last

Return to SIS Projects Listing

Nav Bar link SIS List Nav Bar Link Patuxent Nav Bar Link Biological Resources Nav Bar Link USGS Nav Bar Link Interior Navigation Bar