Patterns of distribution of butterflies and burnets in Portugal (Lepidoptera, Papilionoidea, Hesperiidae, Zygaenidae)

Abstract

An extensive faunistic database has been set up gathering bibliographic information, data from scientific collections and other relevant unpublished data from the 143 species of continental Portuguese butterflies and burnets (Superfamily Papilionoidea, Families Hesperiidae and Zygaenidae). This database was used to define distribution patterns through the application of factorial correspondence analysis (FCA) to the matrices of frequency and presence-absence data in a 50 x 50 km UTM grid. The identification of faunistic elements and regions was obtained through an automatic application of the classification analysis to the FCA results. In a second instance, we used the same methodology to establish the relationship between previously obtained patterns and a set of environmental variables, in order to determine the factors related to the observed classes. The annual average temperature proved to be the best factor to explain the observed latitudinal gradient in the butterfly distribution. The results show a well-defined northern interior region of high average altitudes and limited in the South by the Serra da Estrela. This area has the largest species richness and hosts the Montesinho Natural Park, which is the most diverse in the country. In the southern half of Portugal, the Algarve deserves a special mention for its group of species with typical Mediterranean requirements.