AndinoHerps 2000 project

AndinoHerps 2000 Team

 

From Oxford University

Nora Schultz:  Project Leader

Benjamin McCormick

Helen Forsey

Jess Mather Hillon

 

From Ecuador/U.S.

Larry Frolich

Diego Almeida

Fernando Nogales

Margarita Mancedo

Cecilia Tobar

Juan Carlos Monge

David Cotacachi

In 1999, the AndinoHerps 2000 project was conceived as an expedition to inventory the herpetofauna of the northern Andes. With the collaboration of local high school and university students, the international AndinoHerps research team spent six weeks in the field in 2000 an 2001, gathering data that now form the baseline demographic information for amphibian populations in the region. Using timed nocturnal transect surveys and intensive day-time quadrant searches, over 300 individuals from at least 18 different species of frogs were found in the region, of which two are now submitted for publication as new species (see New Species). Data were analyzed with reference to three principle types of habitat—agricultural, forest and páramo (high altitude grasslands). The predominant plant species in each habitat were identified for each of the project’s four field sites in order to characterize habitat and level of human intervention. GPS data were gathered to plot exact locations of study sites (see regional map). Spectral analysis of LandSat images were validated by on-the-ground habitat characterization to estimate land cover type for the study zone.

Results from the AndinoHerps 2000 inventory show that the study zone reflects the typical conundrum of amphibian population dynamics (Frolich et al., 2001; Almeida et al., 2001). On the one hand, anecdotal evidence suggests that some now rare species were once extremely common—most notably, the once omnipresent Marsupial Frog (Gastrotheca sp.) was encountered in only one instance during twelve weeks of intensive team field work. At the same time, previous workers had described only four species from the area (Lynch, 196; Lynch & Duellman, 1980; Marsh & Pearman, 199) whereas AndinHerps 2000 found at least fifteen species, of which two have been confirmed by the leading expert on the Andean members of the genus Eleutherodactylus (John Lynch, personal communication) to be previously undescribed. Five other putative new species require additional encounters in order to confirm their status.  Abundance of each species was calculated as the relative number of encounters per hour of search time (see Population Habitat Distribution histogram). Virtually every species was encountered in forest habitat and many were most common there. However, interestingly, all species cross either the forest-páramo or forest-agricultural boundary to be found in two strikingly different environments. In some cases, frequency of occurrence is higher in non-forest than forest environments (e..g., Eleutherodactylus buckleyi). However, encounter numbers are too low to show statistically significant habitat correlations, indicating the limitations of studies that require specialist time in the field.