High predation risk decimates survival during the reproduction season

Predators attack conspicuous prey phenotypes that are present in the environment. Male display behavior of conspicuous nuptial coloration becomes risky in the presence of a predator, and adult males face higher predation risk. High predation risk in one sex will lead to low survival and sex ratio bias in adult cohorts, unless the increased predation risk is compensated by higher escape rate. Here, we tested the hypothesis that sand lizards (Lacerta agilis) have sex-specific predation risk and escape rate. We expected the differences to manifest in changes in sex ratio with age, differences in frequency of tail autotomy, and in sex-specific survival rate. We developed a statistical model to estimate predation risk and escape rate, combining the observed sex ratio and frequency of tail autotomy with likelihood-based survival rate. Using Bayesian framework, we estimated the model parameters. We projected the date of the tail autotomy events from growth rates derived from capture-recapture data measurements. We found statistically stable sex ratio in age groups, equal frequency of tail regenerates between sexes, and similar survival rate. Predation risk is similar between sexes, and escape rate increases survival by about 5%. We found low survival rate and a low number of tail autotomy events in females during months when sand lizards mate and lay eggs, indicating high predator pressure throughout reproduction. Our data show that gravid females fail to escape predation. The risks of reproduction season in an ectotherm are a convolution of morphological changes (conspicuous coloration in males and body allometry changes in gravid females), behavior (nuptial displays), and environmental conditions which challenge lizard thermal performance. Performance of endotherm predators in cold spring months endangers gravid females more than displaying males in bright nuptial coloration

Increasing Incidence of Geomyces destructans Fungus in Bats from the Czech Republic and Slovakia

BACKGROUND: White-nose syndrome is a disease of hibernating insectivorous bats associated with the fungus Geomyces destructans. It first appeared in North America in 2006, where over a million bats died since then. In Europe, G. destructans was first identified in France in 2009. Its distribution, infection dynamics, and effects on hibernating bats in Europe are largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: We screened hibernacula in the Czech Republic and Slovakia for the presence of the fungus during the winter seasons of 2008/2009 and 2009/2010. In winter 2009/2010, we found infected bats in 76 out of 98 surveyed sites, in which the majority had been previously negative. A photographic record of over 6000 hibernating bats, taken since 1994, revealed bats with fungal growths since 1995; however, the incidence of such bats increased in Myotis myotis from 2% in 2007 to 14% by 2010. Microscopic, cultivation and molecular genetic evaluations confirmed the identity of the recently sampled fungus as G. destructans, and demonstrated its continuous distribution in the studied area. At the end of the hibernation season we recorded pathologic changes in the skin of the affected bats, from which the fungus was isolated. We registered no mass mortality caused by the fungus, and the recorded population decline in the last two years of the most affected species, M. myotis, is within the population trend prediction interval. CONCLUSIONS/SIGNIFICANCE: G. destructans was found to be widespread in the Czech Republic and Slovakia, with an epizootic incidence in bats during the most recent years. Further development of the situation urgently requires a detailed pan-European monitoring scheme

Tree of life in a gappy genomic era

Increasing volume of publicly available DNA sequence data enables comprehensive studies that address integrative questions. For these projects, bioinformatic analysis requires advanced methods and computational infrestructure. I present the character of DNA sequence matrices for multilocus datasets, which contain large portions of missing data. A condition critical for analysis of multilocus data is that datasets for all loci or genes need to have partially overlapping taxon sets. The work-flow for analysing such data differs between supermatrix and supertree estimation of species trees. In the supermatrix approach, aligned sequences for all genes are concatenated and the species tree is estimated directly from a partitioned matrix. In the supertree approach, gene sequence alignments are used for inference of gene trees. Those are then combined into a species supertree. Smaller projects could benefit from utilising all available information in the supermatrix. Larger projects should rely on supertree methods for computational optimisation

Školení k fylogenetickým analýzám

Reconstruction of phylogeny plays an important role in presentday science. Aim of this paper is to introduce basic methods of phylogenetic analysis using DNA sequences. In a brief manner, approaches to phylogenetic inference, commonly used methods of tree reconstruction, and models of DNA evolution are presented. This compendium may serve as an introduction to this exciting discipline of biological science

Reconstructing phylogeny from patchy data of rodents

To reveal phylogeny of sparsely sequenced taxa, standard methods could not be successfully used due to patchy character of data and new methods had to be developed. We summarize such methods and present their funcionality on phylogeny of Arvicolini voles. Analyzing tree space with terraces, we have found that supermatrix approach is superior to supertree approach in extracting signal from data and determining a resolved and well-supported phylogeny. The most widely used program from Bayesian phylogeny inference fails to determine the correct lengths of branches in a large supermatrix with a lot of missing data, it still successfully determines the true tree topology

Genetic diversity in populations

Genetic diversity accumulates over time on the level of DNA sequence with accumulation of mutations. It is additionally increased with population admixture, and the decrease in genetic diversity is often the first indication of detrimental processes affecting populations, such as reduction in the number of breeding individuals or breeding of close relatives. Nucleotide diversity shows how different the sequences of a given gene are in a population. Gene diversity estimates how likely two individuals are to share the same sequence of a gene. Number of alleles is the count of different versions of a gene with differing sequences, and this is corrected for sample size in estimation of allelic richness. Heterozygosity is the average frequency that an individual will have two different copies of a gene

Extrakce odlehlých hodnot z nevyvážených datových sad

In this paper, we presented an outlier detection method, designed for small datasets, such as datasets in animal group behaviour research. The method was aimed at detection of global outliers in unlabelled datasets where inliers form one predominant cluster and the outliers are at distances from the centre of the cluster. Simultaneously, the number of inliers was much higher than the number of outliers. The extraction of exceptional observations (EEO) method was based on the Mahalanobis distance with one tuning parameter. We proposed a visualization method, which allows expert estimation of the tuning parameter value. The method was tested and evaluated on 44 datasets. Excellent results, fully comparable with other methods, were obtained on datasets satisfying the method requirements. For large datasets, the higher computational requirement of this method might be prohibitive. This drawback can be partially suppressed with an alternative distance measure. We proposed to use Euclidean distance in combination with standard deviation normalization as a reliableČlánek přináší popis metody určené k detekci odlehlých hodnot v datových sadách s malým počtem pozorování, kde správná pozorování tvoří jeden klastr. Pro správnou funkčnost je potřeba, aby počet správných pozorování byl výrazně vyšší než počet odlehlých pozorování. Metoda je založena na Mahalanobis vzdálenosti

Data from: A skull might lie: modelling ancestral ranges and diet from genes and shape of tree squirrels

Tropical forests of Central and South America represent hotspots of biological diversity. Tree squirrels of the tribe Sciurini are an excellent model system for the study of tropical biodiversity as these squirrels disperse exceptional distances, and after colonizing the tropics of the Central and South America, they have diversified rapidly. Here, we compare signals from DNA sequences with morphological signals using pictures of skulls and computational simulations. Phylogenetic analyses reveal step-wise geographic divergence across the Northern Hemisphere. In Central and South America, tree squirrels form two separate clades, which split from a common ancestor. Simulations of ancestral distributions show western Amazonia as the epicenter of speciation in South America. This finding suggests that wet tropical forests on the foothills of Andes possibly served as refugia of squirrel diversification during Pleistocene climatic oscillations. Comparison of phylogeny and morphology reveals one major discrepancy: Microsciurus species are a single clade morphologically but are polyphyletic genetically. Modeling of morphology–diet relationships shows that the only group of species with a direct link between skull shape and diet are the bark-gleaning insectivorous species of Microsciurus. This finding suggests that the current designation of Microsciurus as a genus is based on convergent ecologically driven changes in morphology

Data from: A skull might lie: modelling ancestral ranges and diet from genes and shape of tree squirrels

Tropical forests of Central and South America represent hotspots of biological diversity. Tree squirrels of the tribe Sciurini are an excellent model system for the study of tropical biodiversity as these squirrels disperse exceptional distances, and after colonizing the tropics of the Central and South America, they have diversified rapidly. Here, we compare signals from DNA sequences with morphological signals using pictures of skulls and computational simulations. Phylogenetic analyses reveal step-wise geographic divergence across the Northern Hemisphere. In Central and South America, tree squirrels form two separate clades, which split from a common ancestor. Simulations of ancestral distributions show western Amazonia as the epicenter of speciation in South America. This finding suggests that wet tropical forests on the foothills of Andes possibly served as refugia of squirrel diversification during Pleistocene climatic oscillations. Comparison of phylogeny and morphology reveals one major discrepancy: Microsciurus species are a single clade morphologically but are polyphyletic genetically. Modeling of morphology–diet relationships shows that the only group of species with a direct link between skull shape and diet are the bark-gleaning insectivorous species of Microsciurus. This finding suggests that the current designation of Microsciurus as a genus is based on convergent ecologically driven changes in morphology