DOI: 10.5061/dryad.w0vt4b8zc
title: How environmental factors affect the abundance and distribution of two congeneric species of Amazonian frogs

description: In this study, we test the hypothesis that, at a fine scale, environmental
 variables influence differently sister species that live in sympatry and
 are phylogenetically closely related. We sampled two Amazonian anuran
 species, Phyzelaphryne miriamae and Phyzelaphryne sp., in 11 permanent
 sampling modules distributed across ~600 km in the Purus-Madeira
 Interfluve between 2013 and 2014. Using mixed generalized linear models,
 we found that the species have distinct environmental associations, which
 may facilitate their coexistence in sympatry. Phyzelaphryne miriamae was
 more frequent in environments with low precipitation and low water tables,
 suggesting this species is better adapted to live in drier places. In
 contrast, Phyzelaphryne sp. appeared to be a generalist regarding to
 habitat and resource use. These patterns are in accordance with the
 hypothesis that environmental variables influence sister species
 differently on a fine scale. Phyzelaphryne miriamae is larger than
 Phyzelaphryne sp., which may make it more resistant to dehydration,
 allowing it to explore drier environments. In conclusion, our results are
 in concordance with the hypothesis that the evolution of characteristics
 resulting from selection may have reduced competition for resources
 between closely related species, thus facilitating coexistence in
 sympatry.
description: Data were collected in 11
 RAPELD permanent sampling modules (Magnusson et al., 2013) distributed along approximately 600 km in the
 MPI. Modules are located approximately every ~60 km along the BR-319, a
 federal highway that runs through the interfluve from north to south. They
 are positioned perpendicular to the highway and have two parallel 5-km
 tracks of separated by 1 km. A 250 m long plot is located every 1 km along
 each trail, totaling 5 plots per track and 10 plots per module. Sampling
 of the focal species was carried out in the rainy seasons (October–March)
 of 2013 and 2014 through auditory and visual sampling during their
 afternoon activity period (16–19h). Plots were sampled once in each of two
 field campaigns. Frogs
 were detected by visual and auditory surveys, but almost all detections of
 the focal species in this study were by auditory cues, which are much less
 affected by vegetation clutter than visual records. Each 250-m plot was
 divided into 10-m segments, and the presence or absence of the species was
 recorded in each segment, giving an abundance index varying from zero to
 25.
description: # How environmental factors affect the abundance and distribution of two
 congeneric species of Amazonian frogs
 [https://doi.org/10.5061/dryad.w0vt4b8zc](https://doi.org/10.5061/dryad.w0vt4b8zc) In this study, we test the hypothesis that, at a fine-scale, environmental variables influence differently sister-species that live in sympatry and are phylogenetically closely related. We sampled two Amazonian anuran species, *Phyzelaphryne miriamae* and *Phyzelaphryne* sp., in 11 permanent sampling modules distributed across \~600 km in the Purus-Madeira Interfluve between 2013 and 2014. Using mixed generalized linear models, we found that the species have distinct environmental associations, which may facilitate their coexistence in sympatry. *Phyzelaphryne miriamae* was more frequent in environments with low precipitation and low water tables, suggesting this species is better adapted to live in drier places. In contrast, *Phyzelaphryne* sp. appeared to be a generalist regarding to habitat and resource use. These patterns are in accordance with the hypothesis that environmental variables influence sister-species differently on a fine-scale. *Phyzelaphryne miriamae* is larger than *Phyzelaphryne* sp., which may make it more resistant to dehydration, allowing it to explore drier environments. In conclusion, our results are in concordance with the hypothesis that the evolution of characteristics resulting from selection may have reduced competition for resources between closely related species, thus facilitating coexistence in sympatry. ## Description of the data and file structure The dataset provides a view of the abundance indices for two species—Phyzelaphryne miriamae and Phyzelaphryne sp.—across the Purus-Madeira Interfluve. Within the "Sample Unit" column, codes are formatted with underscores to delineate various sampling parameters. Specifically, a prefix "M" followed by a numerical identifier indicates the sampling module. Furthermore, the alphabetic indicators 'TN' and 'TS' designate northern and southern 5-km-long survey tracks that are spaced 1 km apart, termed as "Track North" and "Track South," respectively. Lastly, the numbers ranging from 0500 to 4500 reveal the distance, in meters, from the starting point of each 5-km track to the respective sampling plotsSharing/Access information This is a section for linking to other ways to access the data, and for linking to sources the data is derived from, if any. More information about sample sites and design in the Purus-Madeira Interfluve is available in https://ppbio.inpa.gov.br/en/Sites/BR319