Distribution of butterflies (Lepidoptera) in a successional mosaic of Mediterranean mountain habitats

Abstract

The distribution of butterflies was analysed in a mosaic of different types of habitats in a typical Ibero-Supramediterranean plant landscape. This mosaic landscape is composed of oak forests (Quercus pyrenaica) and their corresponding shrub and grassland successional communities. The observed patterns were based on butterfly-flower interactions in two consecutive years (2017-2018) recorded in different habitats. The results of the nestedness analysis indicated that the same butterfly community exploits all of the successional plant-communities, but some differences due to the availability of flowers. The foraging for nectar sources was mostly restricted to a few flowering plants: Rubus ulmifolius, Carduus carpetanus, Thymus pulegioides and Dianthus deltoides. Some butterflies changed their flower-visiting patterns over the two years studied. The distribution of butterflies was strongly linked to the distribution of their preferred nectar sources and changes in the use of these sources modified habitat use. The area of Rubus shrubland is a small but highly used habitat in this area, given the presence of Rubus ulmifolius, a plant species with high coverage and abundance of nectar, makes this area much better for foraging than other habitats. The Cytisus and Rubus shrublands were used more than grassland, indicating that seral habitats can be more valuable than traditional open grassland and forest habitats for butterflies.