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among habitats, we estimated similarity
by a Principal Component Analysis and
the Pearson correlation coefficient was
calculated to identify the relationship
between the environmental variables and to
identify groups of non-correlated variables
inside the microhabitats. We used forward
stepwise multiple regression models in the
software STATISTICA 6.0 (Statsoft 2001),
to detect structural and environmental
variables associated with the presence of the
most common frogs. We recorded a total of
Figure 1. Principal Component Analysis based on the standardized abundances of the anuran species. Each
triangle represents the coordinates of the species composition in each habitat. The first letter in the acronymus
makes reference to Pasture (P in triangle) or Forest (F in square); the second letter (separated by a line) represents
the habitats: stream (S), exterior (Ex), outer and internal edge (E) and interior (I). Isaacs & Urbina.
251 anurans of eight species. The richness
was higher in the forest (seven species)
than in pasture (four species). Most species
of the ensemble (75%) inhabited the forest
habitats, whereas 50% of the anuran species
inhabited the pasture. Of the environmental
variables, slope and distance to streams
influenced the distribution of all modeled
Pristimantis species, although this genus
exhibits direct development and doesn’t
require bodies of water for its reproduction.
The canopy cover had a high explanatory
power (through beta regressors) on
the presence of anuran species in the
microhabitat; whereas temperature and
relative humidity did not, suggesting that
temperature and relative humidity may be
less important for frog distributions along
pasture-forest gradients in cloud forest
landscapes. The anthropogenic disturbance
in the landscape seems to affect the
presence of two rare species (Pristimantis
ptochus and Pristimantis kelephas)
suggesting that these species display a high
degree of sensitivity to the transformation
of the cloud forest. Future cloud forest
management research needs to incorporate
anthropogenic disturbance effects, because
it strongly interacts with edge and matrix
effects, affecting the habitat quality and
the persistence of species in the landscape.
Full article: Paola Johanna
Isaacs Cubides & José Nicolás
Urbina Cardona. Anthropogenic
Disturbance and Edge Effects on
Anuran Assemblages Inhabiting
Cloud Forest Fragments in
Colombia. Natureza & Conservação
9(1):39-46, July 2011.
Composition of amphibian
assemblages in agroecosystems
from the central region of
Argentina.
By Clarisa de L. Bionda, Ismael E. di Tada &
Rafael C. Lajmanovich.
The conversion of forest to agricultural
land is occurring at rapid rates in
many Neotropical areas. This trend has
spurred research to examine the role that
agroecosystems play in providing habitat
for Neotropical organisms. In this sense,
Argentina is the third world’s largest
producer of soybeans (Glycine max Merril L).
Particularly, the central region of Argentina
has been most affected by agricultural
development. Few studies, (e.g. Peltzer et
al. 2006) however, have been conducted
on the amphibian assemblage composition
and dynamics of agroecosystems in central
region of Argentina. Our main objective is to
determine the species richness and diversity
of anuran assemblages in agroecosystems
from the central region of Argentina. We
sampled two agroecosystems (AG) (AG 1, 9
ha: 33°05’S 64°26’W, AG 2, 12 ha: 33°05’S
64°25’W) in Rio Cuarto, Cordoba province,
Argentina. We conducted surveys from
December to April (2006-2007). Specimens
were captured using live pitfall trap transects.
The agroecosystem 1 (AG 1) was devoted to
soybean crop and two agroecosystems were
used for cattle grazing. The permanent and
temporary ponds at each site are used for
cattle consumption and irrigation to crop
during periods of drought. A total of 561
amphibians of seven species, belonging
to four families (Bufonidae, Leiuperidae,
Cycloramphidae, and Leptodactylidae) were
recorded. We find strong positive association
between both species richness and anuran
abundance with habitat variables as rainfall
and rain-day. The anuran richness observed
in the studied areas is similar to other sites
with level of alteration comparable, but the
anuran richness and abundance observed
here is lower compared with the records
of anuran species for the region before
agricultural development. Agricultural
landscapes represent environments where
unpredictable in humidity, particularly
at the start of breeding season, is a factor
that may limit the modes and reproductive
activity in amphibians. Moreover, the
presence of a chemical contaminant in the
breeding sites due to agricultural activities,
also could contribute to regression of the
assemblage anuran diversity and richness.
Consequently, agricultural landscapes can
possibly restrict the presence of certain
species. Thus, these results have suggested
that amphibians may be particularly affected
by habitat modification and degradation due
to agricultural activities in the central region
of Argentina, and it may be contributing to
regression of their diversity and richness.
Full article: Bionda C.L., di
Tada I.E. and Lajmanovich R.C.
2011. Composition of amphibian
assemblages in agroecosystems from
the central region of Argentina.
Russian Journal of Herpetology 18:
93-98.
Deep intra-island divergence
of a montane forest endemic:
phylogeography of the Puerto
Rican frog Eleutherodactylus
portoricensis (Anura:
Eleutherodactylidae)
By Brittany S. Barker, Robert B. Waide & Joseph
A. Cook
Hypotheses proposed for lineage
diversification of tropical montane
species have rarely been tested within
oceanic islands. Our goal was to understand
how basin barriers and Pleistocene climatic
fluctuations shaped the distribution
of diversity in Eleutherodactylus
40 | FrogLog Vol. 98 | September 2011