1,721,153 research outputs found
DIETARY PATTERNS AND OVERLAP IN AN AMPHIBIAN ASSEMBLAGE AT A POND IN MEDITERRANEAN CENTRAL ITALY RID F-2663-2011
No full textSpatio-temporal resource use at a microhabitat scale in an amphibian community at a pond in Mediterranean Central Italy
No full textA review of mono-and bispecific genera of amphibians worldwide
No full textMonospecific and bispecific genera are of particular interest in studies of taxonomic diversity and speciation evolution. Here, the distribution patterns of mono-and bispecific amphibians worldwide are investigated, with some discussion of on the conservation implications also presented. Based on an online database search (available from the American Museum of Natural History, New York), we found that the mean number of mono-and bispecific genera was similar among zoogeographic regions, with a total of 120 mono-(95 Anura, 17 Caudata, 8 Gymnophiona) and 65 bispecific (48 Anura, 10 Caudata, 7 Gymnophiona) genera. Out of 73 known amphibian families worldwide, only 35.6 % of them do not contain any mono-or bispecific genera. The frequency of mono-or bispecific genera by family was not significantly different among Anura, Caudata and Gymnophiona. There was a general tendency for the number of mono-and bispecific genera of amphibians to be positively correlated with the total number of genera in that family. In Anura, there was a preponderance of mono-specific genera in Afrotropical and Neotropical regions. Concerning bispecific genera, there was a clear preponderance in the Neotropical region for anurans. There was a positive correlation between the number of threatened genera (according to the IUCN Red List) in both the mono-and bispecific groups and the relative number of species in each taxon, thus showing that taxonomical speciosity clearly influences the frequency of occurrence of mono-and bispecific taxa in each family and order. In this regard, Anura dominated in both the number of worldwide described mono-and bispecific taxa as well as in that of the threatened ones according to IUCN Red List
Dieta ry patte rns and overlap in an amphibian assemblage at a pond in Mediterranean Central Italy
No full textThe trophic niche characteristics of an amphibian assemblage were studied at a
pond locality in Canale Monterano, province of Roma, Central Italy. The assemblage consisted
of six species, four anurans (Bufo bufo, Hyla intermedia, Rana dalmatina, Pelophylax skl. esculentus),
and two salamanders (Triturus carnifex, Triturus vulgaris). Food contents were obtained
by stomach flushing. Stomach vacuity index varied substantially among species, and the species
spending longer timespan within the reproductive site were also those with lower vacuity index
values. Correspondence analysis discriminated two groups of species: one feeding mainly on
terrestrial prey and the other on aquatic prey. Pseudo-community analysis revealed that the terrestrial
guild of species was non-randomly structured when analysed by RA2 algorithm for volume
of prey but neither for number of prey, nor for both number and volume of prey analysed by
RA3. The aquatic subset of species appeared to be randomly assembled according to both RA2
and RA3 algorithms, either for number or for volume of prey. These results indicate that for terrestrial
species, micro-habitat resource partitioning and body size discrepancy among species
could be the factors influencing dietary patterns and facilitating species coexistence, whereas
for aquatic species the observed high overlap in diet spectrum is mainly due to both generalist
feeding habits of newts and the superabundance of food resources occurring at the study pond
Null models reveal that patch quality metters for the conservation of complex bird communities in Mediterranean hatitats
No full textin pres
Spatio-temporal resource use at a microhabitat scale in an amphibian community at a pond in Mediterranean Central Italy
No full textThe micro-habitat use in relation to the spatial and temporal context was studied
in a six-species-community of amphibians in a Mediterranean pond in Central Italy. Several
concurrent sets of statistical analyses, including univariate, multivariate and null model simulations,
were used in order to interpret the community structure. In terms of micro-habitat selection,
the newt species Tr i t u rus carnifex and T. vulgaris used primarily the aquatic habitats for most of the time spent in the pond, whereas the anuran species (Bufo bufo, Hyla intermedia,
Rana dalmatina and the green frogs) used mainly the terrestrial micro-habitats adjacent to the
pond except during the reproductive period when they used also the aquatic micro-habitats. A PCA analysis classifying the amphibian species on the basis of their spatio-temporal habitat use
put each species in a separate part of the multidimensional space, whereas another set of PCA
analysis revealed that, on the basis of the use of the aquatic micro-habitats, there were four
‘groups’: a) Hyla intermedia and the green frogs; b) Bufo bufo and Rana dalmatina; c) Tr i t u ru s
vulgaris; d) Triturus carnifex. Some species used the micro-habitats types in relation to their relative
availability in the field, whereas other were clearly selective in their requirements. Null
model analyses based on Monte Carlo permutations of overlap values (RA2 and RA3 algorithms)showed that the various species were arranged in the micro-habitat scale in a non-random way. The general implications of these results are discussed
“Heaven” of Data Deficient Species: The Conservation Status of the Endemic Amphibian Fauna of Vietnam
Full text linkPredicting the true status of Data Deficient (DD) species is a prominent theme in recent conservation biology, but there still is much debate regarding the conservation approach that should be used for DD taxa and no definitive conclusions are yet available. We review and analyse the current data available on the conservation status of amphibians in Vietnam, with an emphasis on the DD species. We also compare Vietnamese DD frequency of occurrence with other regions of the world, examine the extent of the range of taxa divided by Red List status, and explore the protection attributes of the taxa based on their inclusion within protected areas of Vietnam. We documented that the analysis of amphibians in Southeast Asia, and especially in Vietnam, substantially agrees with patterns highlighted by previous global research, and confirms the risk that several DD species may silently go extinct without their actual risk ever being recognized. Importantly, our study showed that fine-scale analyses are essential to highlight the potential drivers of extinction risk for the DD species of amphibians. A crucial next step for conservation policies in Vietnam (and in surrounding countries) is developing and implementing species-specific studies targeted at addressing each species’ drivers of extinction and determining science-based strategies for minimizing their extinction risk
Flight initiation distance in relation to substratum type, sex, reproductive status and tail condition in two lacertids with contrasting habits
No full textSeasonal patterns of activity and community structure in an amphibian assemblage at a pond network with variable hydrology
No full textWe studied community structure and seasonal activity patterns in a system of four ponds
with seasonally-variable hydrology at a Mediterranean area in central Italy. We used a set
of field methods to assess species presence and relative frequency of observation. The
network of ponds was inhabited by six species of amphibians, two salamanders and four
frogs. The breeding phenology of the six species did not vary remarkably among ponds,
but there were significant differences among species in use of ponds. Factorial analysis
of pond similarity drawn from percentage composition of the amphibian fauna, revealed
that each of the four ponds was treatable as independent units, with no influence of relative
inter-pond distance. PCA analysis allowed us to spatially arrange the amphibian species
into three main groups: two were monospecific groups (i.e., Triturus vulgaris and Bufo
bufo) and the third consisted of those species that selected not only the largest-deepest
ponds, but also the ephemeral ones (i.e., Triturus carnifex, Hyla intermedia, the green frogs and Rana dalmatina). Our results suggest that the inter-pond differences in riparian vegetation,
water depth, aquatic vegetation structure/abundance, and soil composition may
produce differences among pond ecological characteristics (i.e., water turbidity and temperature,
shelter availability, abundance of oviposition micro-sites), which may in turn influence
different patterns of use by amphibians. To our knowledge, this is the first study
emphasizing the potential role of heterochrony in the maintenance of a high species richness in Mediterranean amphibian communities. Preservation of freshwater vertebrate
biodiversity requires management and protection not only of the main ponds and water bodies but also the temporary and ephemeral shallow ponds
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