A Permutation-based Combination of Sign Tests for Assessing Habitat Selection

The analysis of habitat use in radio-tagged animals is approached by comparing the portions of use vs the portions of availability observed for each habitat type. Since data are linearly dependent with singular variance-covariance matrices, standard multivariate statistical test cannot be applied. To overcome the problem, compositional data analysis is customary performed via log-ratio transform of sample observations. The procedure is criticized in this paper, emphasizing the many drawbacks which may arise from the use of compositional analysis. An alternative nonparametric solution is proposed in the framework of multiple testing. The habitat use is assessed separately for each habitat type by means of the sign test performed on the original observations. The resulting p-values are combined in an overall test statistic whose significance is determined permuting sample observations. The theoretical findings of the paper are checked by simulation studies. Applications to some case studies are considered.compositional data analysis, Johnson’s second order selection, Johnson’s third order selection, Monte Carlo studies, multiple testing, random habitat use.

Preference of Polistes dominula wasps for trumpet creepers when infected by Xenos vesparum : A novel example of co-evolved traits between host and parasite

Acknowledgments The authors are grateful to Marta Mariotti, Laura Maleci, Claudia Giuliani and Corrado Tani for fruitful discussions on Campsis radicans identification and morphology. We also thank two anonymous reviewers and Francesco Dessı`-Fulgheri for their helpful suggestions; Marco Vannini and Leonardo Dapporto for their support in the statistical analyses; Alessandro Pagnini for his help in the search of Campsis radicans bushes in Tuscany; Rita Cervo, Stefano Turillazzi and the members of the Florence Group for the Study of Social Wasps for their assistance during this study, both in the field and in the laboratory.Peer reviewedPublisher PD

Effects of Milling and UV Pretreatment on the Pyrolytic Behavior and Thermal Stability of Softwood and Hardwood

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A Strepsipteran parasite extends the lifespan of workers in a social wasp

Acknowledgements The authors are grateful to Rita Cervo, Stefano Turillazzi and the members of the Florence Group for the Study of Social Wasps for their assistance during this study, both in the field and in the laboratory. The authors would also like to thank two anonymous reviewers for their helpful comments on the manuscript.Peer reviewedPublisher PD

Le iponatremie

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