Different habitat selection by two sympatric Maculinea butterflies at small spatial scale


Ádám Kőrösi, Baross u. 13, H–1088 Budapest, Hungary. E-mail: korosi@nhmus.hu


Abstract.  1. Worldwide extinction of species due to habitat loss and habitat degradation can be recognised among butterflies pronouncedly. Therefore, conservation biologists devote special attention to identify the most important ecological factors affecting distribution and survival of butterflies. These efforts have been dominated by landscape-scale studies, although variation in habitat quality at smaller spatial scales may be of crucial importance. This applies for the highly specialised Maculinea species, which usually do not form classic metapopulations.

2. Maculinea nausithous and Maculinea teleius use the same larval food plant and usually occupy the same habitats in Europe. Afforestation of meadows due to abandonment is a major threat for these species. However, few if any studies have assessed the effects that proximity of forest edges may have on the habitat selection by adult butterflies at the scale of local populations. Here, we aimed to test these effects within one habitat fragment based on an intensive mark–release–recapture sampling.

3. Distribution of M. nausithous was aggregated and its density was highly positively influenced by the proportion of afforested meadow edges, while M. teleius showed no preference for afforested edges. Despite their different within-habitat distribution, the movement of both species was restricted to smaller parts of the habitat.

4. Our results suggest that M. nausithous has a narrower niche in the study region, which is most likely due to that its only host ant can find suitable microclimatic conditions at the afforested edges of wet meadows. This implies that habitat patches are not equally used by the two species and hence different management approaches are desirable for their conservation.