. (2013). Systematics of spiny-backed treefrogs (Hylidae: Osteocephalus): an Amazonian puzzle. -Zoologica Scripta, 42, 351-380. Spiny-backed tree frogs of the genus Osteocephalus are conspicuous components of the tropical wet forests of the Amazon and the Guiana Shield. Here, we revise the phylogenetic relationships of Osteocephalus and its sister group Tepuihyla, using up to 6134 bp of DNA sequences of nine mitochondrial and one nuclear gene for 338 specimens from eight countries and 218 localities, representing 89% of the 28 currently recognized nominal species. Our phylogenetic analyses reveal (i) the paraphyly of Osteocephalus with respect to Tepuihyla, (ii) the placement of 'Hyla' warreni as sister to Tepuihyla, (iii) the non-monophyly of several currently recognized species within Osteocephalus and (iv) the presence of low (<1%) and overlapping genetic distances among phenotypically well-characterized nominal species (e.g. O. taurinus and O. oophagus) for the 16S gene fragment used in amphibian DNA barcoding. We propose a new taxonomy, securing the monophyly of Osteocephalus and Tepuihyla by rearranging and redefining the content of both genera and also erect a new genus for the sister group of Osteocephalus. The colouration of newly metamorphosed individuals is proposed as a morphological synapomorphy for Osteocephalus. We recognize and define five monophyletic species groups within Osteocephalus, synonymize three species of Osteocephalus (O. germani, O. phasmatus and O. vilmae) and three species of Tepuihyla (T. celsae, T. galani and T. talbergae) and reallocate three species (Hyla helenae to Osteocephalus, O. exophthalmus to Tepuihyla and O. pearsoni to Dryaderces gen. n.). Furthermore, we flag nine putative new species (an increase to 138% of the current diversity). We conclude that species numbers are largely underestimated, with most hidden diversity centred on widespread and polymorphic nominal species. The evolutionary origin of breeding strategies within Osteocephalus is discussed in the light of this new phylogenetic hypothesis, and a novel type of amplexus (gular amplexus) is described. Corresponding author: Karl-Heinz Jungfer, Institute of Integrated Sciences, Department of Biology, University of Koblenz-Landau, Universit€ atsstr. 1, 56070 Koblenz, Germany. E-mail: khjungfer@aol.com Juli an Faivovich, Divisi on Herpetolog ıa, Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia'-CONICET, Angel Gallardo 470, C1405DJR, Buenos Aires, Argentina and Departamento de Biodiversidad y Biologia Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina. E-mail: julian@macn.gov.ar Jos e M. Padial, Section of Amphibians and Reptiles, Carnegie Museum of Natural History, 4400 Forbes Avenue, Pittsburgh, PA, 15213-4080 Systematics of spiny-backed treefrogs K.-H. Jungfer et al. IntroductionTreefrogs of the genus Osteocephalus constitute an important component of the amphibian fauna of the Amazonian and Guianan regions of South America. Their distributions...
Tropical South America is rich in different groups of pollinators, but the biotic and abiotic factors determining the geographical distribution of their species richness are poorly understood. We analyzed the species richness of three groups of pollinators (bees and wasps, butterflies, hummingbirds) in six tropical forests in the Bolivian lowlands along a gradient of climatic seasonality and precipitation ranging from 410 mm to 6250 mm. At each site, we sampled the three pollinator groups and their food plants twice for 16 days in both the dry and rainy seasons. The richness of the pollinator groups was related to climatic factors by linear regressions. Differences in species numbers between pollinator groups were analyzed by Wilcoxon tests for matched pairs and the proportion in species numbers between pollinator groups by correlation analyses. Species richness of hummingbirds was most closely correlated to the continuous availability of food, that of bees and wasps to the number of food plant species and flowers, and that of butterflies to air temperature. Only the species number of butterflies differed significantly between seasons. We were not able to find shifts in the proportion of species numbers of the different groups of pollinators along the study gradient. Thus, we conclude that the diversity of pollinator guilds is determined by group-specific factors and that the constant proportions in species numbers of the different pollinator groups constitute a general pattern.
Abstract. We address a poorly understood aspect of ecological niche modeling: its sensitivity to different levels of geographic uncertainty in organism occurrence data. Our primary interest was to assess how accuracy degrades under increasing uncertainty, with performance measured indirectly through model consistency. We used Monte Carlo simulations and a similarity measure to assess model sensitivity across three variables: locality accuracy, niche modeling method, and species. Randomly generated data sets with known levels of locality uncertainty were compared to an original prediction using Fuzzy Kappa. Data sets where locality uncertainty is low were expected to produce similar distribution maps to the original. In contrast, data sets where locality uncertainty is high were expected to produce less similar maps. BIOCLIM, DOMAIN, Maxent and GARP were used to predict the distributions for 1200 simulated datasets (3 species x 4 buffer sizes x 100 randomized data sets). Thus, our experimental design produced a total of 4800 similarity measures, with each of the simulated distributions compared to the prediction of the original data set and corresponding modeling method. A general linear model (GLM) analysis was performed which enables us to simultaneously measure the effect of buffer size, modeling method, and species, as well as interactions among all variables. Our results show that modeling method has the largest effect on similarity scores and uniquely accounts for 40% of the total variance in the model. The second most important factor was buffer size, but it uniquely accounts for only 3% of the variation in the model. The newer and currently more popular methods, GARP and Maxent, were shown to produce more inconsistent predictions than the earlier and simpler methods, BIOCLIM and DOMAIN. Understanding the performance of different niche modeling methods under varying levels of geographic uncertainty is an important step toward more productive applications of historical biodiversity collections.
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