Swedish Butterfly Monitoring Scheme, annual report for 2011
Förlag: Department of Biology, Lund University
This is the second annual report for the Swedish Butterfly Monitoring Scheme, a national monitoring programme coordinated by Lund University for the Swedish Environmental Protection Agency since 2010. The programme is a partnership between the Entomological Society of Sweden, the Swedish Environmental Protection Agency, Lund University, the Swedish University of Agricultural Sciences and the Swedish County Administration Boards. The monitoring scheme is volunteer-based and runs from April 15th to September 15th annually. Sites are visited 3-7 times per season and are surveyed using a standardized, common methodology. Two different recording methods are used in the Swedish Butterfly Monitoring Scheme. One is the point site counts which cover an area with a 25 m radius for 15 min per visit. The other method is fixed-route Pollard walk transects, typically 1-3 km in length. These two methods enable the monitoring scheme to assess yearly changes both in the number of butterflies seen and in species composition. The second year’s monitoring has produced butterfly data from 98 fixed-route walks and 173 point sites, representing a 66% increase in the number of transects and a 60% increase in the number of point sites. The sites and walks are located across the whole country, from Falsterbo in the South to Luleå in the North. In 2011, 203 volunteer recorders participated in the Swedish Butterfly Monitoring Scheme and have counted 54 700 butterflies of 92 different species. The number of volunteers has increased with 72% and the coverage of the Swedish fauna has increased by 11%. One biannual species seen in 2010, the Baltic Grayling, was not recorded in 2011. On average, 14.5 species have been observed at the point sites while 21.1 have been observed along transects. In this report, observations from 2011 of each species are shown as total counts, distribution maps, and flight period histograms. The most numerous species in 2011 was the Ringlet, followed by the Meadow Brown and the Small Tortoiseshell. Trends between 2010 and 2011 have been analysed in terms of deviations from expected numbers of individuals. Additionally, because of the high number of sites monitored already in 2010-2011, it has been possible to analyse population trends for 12 grassland butterflies using the analytical tool TRIM, thereby contributing to the 2012 European Butterfly Indicator for Grassland species.
- ISBN: 978-91-7473-354-9