136 Piotr Nowicki et al. © PENSOFT Publishers Sofia – Moscow Population dynamics in the genus Maculinea revisited: comparative study of sympatric M. alcon and M. teleius Piotr Nowicki 1 , Simona Bonelli 2 , Francesca Barbero 2 & Emilio Balletto 2 1 UJAG - Jagiellonian University, Institute of Environmental Sciences, Gronostajowa 7, 30-387 Kraków, Poland 2 University of Turin, Department of Human and Animal Biology, Via Accademia Albertina 13, 10123 Turin, Italy Contact: nowic@eko.uj.edu.pl Population dynamics of most butterfly species are believed to be predominantly affected by environmental variation, in particular in resources and weather patterns (Dempster 1983). However, according to mathematical models Maculinea butterflies should rather be regulated by density dependent trends (Hochberg et at. 1994, Thomas et al. 1998). These models also predicted that populations of ‘cuckoo’ species (M. alcon, M. rebeli ) should be more stable than those of ‘predatory’ ones (M. arion, M. nausithous, M. teleius). We have decided to test the above predictions using the data provided by long-term Maculinea monitoring in Caselette near Turin, northern Italy (45°07' N; 07°29' E). The site is approximately 3-ha wet meadow dominated by Molinia coerulea. It is located in the Susa Valley, at an altitude of ca. 360 m above sea-level. Sympatric occurrence of M. teleius and M. alcon, which at this site fly simultaneously from mid July to late August, and are thus influenced by the same weather conditions, makes this system ideal for a comparative study of population dynamics of both species. Moreover, the site is well isolated, with the nearest other Maculinea sites being 2 km away, which makes population dynamics in Caselette independent of any possi- ble effect of immigration. Populations of both species have been investigated since 1997 with intensive mark-release- recapture (MRR). Each year sampling was conducted regularly on every second day (with very few exceptions) throughout the entire flight period. The data collected were analysed with the with the program MARK 2.1 (White & Burnham 1999). Cormack-Jolly-Seber type constrained models (Schwarz & Arnason 1996) were applied according to the procedure described by Now- icki et al. (2005b). Model selection routine invariable suggested the model ϕ(.)p(.) (the model with survival and capture probability equal for both sexes and constant over time) as the best fitting the data. For both species model parameters were fairly uniform across the years (Fig. 1), further increasing the reliability of the results. Survival estimates obtained were within a typical range for Maculinea butterflies (Pfeifer et al. 2000, Nowicki et al. 2005b), but capture probabilities proved to be relatively low (compare Mey- er-Hozak 2000, Nowicki et al. 2005c). Both capture probabilities and survival were slightly, but J. Settele, E. Kühn & J.A. Thomas (Eds) 2005 Studies on the Ecology and Conservation of Butterflies in Europe Vol. 2: Species Ecology along a European Gradient: Maculinea Butterflies as a Model, pp. 136-139