The meadow brown in towns and cities
The meadow brown is one of the butterflies to benefit from wildlife-friendly management strategies in towns and cities.
Trends in the meadow brown
The verges and other grassy vegetations in some Dutch towns and cities are being managed in a wildlife-friendly way. In the locations with such management the meadow brown is increasing; in locations with conventional management it is stable. In 2001 there were many more meadow brown butterflies in areas with wildlife-friendly management than in areas with conventional management (per transect the averages were 100 individuals versus 23 in 2001).
Trends in other butterfly species
In some of the other species studied there was also found a difference in the number of individuals between wildlife-friendly management and conventional management. For example, the figures in 2001 for the Essex skipper were (on average) 27 versus 8 individuals per transect; for the common blue they were (on average) 4 versus 1 individual. This suggests that these two species do benefit from wildlife-friendly management, even though there is no difference in the trend for the species. The latter may be because they are quickly able to find suitable locations.
Technical note
The figure shows the trend (in index numbers) of the meadow brown.
The numbers are based on the Ecological Monitoring Network's national network for monitoring butterflies. This involves counting butterflies along transects of about 1 kilometre every week from 1 April until 1 September. In urban areas, 54 transects with wildlife-friendly management have been compared with 46 with conventional management. The number of individuals is the mean number of individuals per transect per year in 2001.
The conventional management of grassy vegetations is (1) keeping the vegetation short by mowing or strimming and then leaving the grass cuttings, or (2) mowing infrequently, allowing the vegetation to become coarser. Wildlife-friendly or ecological management in urban areas takes account of wild plants and animals by not mowing too frequently and by removing the grass cuttings. This allows wild plants to bloom in May and June. As expected, therefore, this management strategy is beneficial for the development of the host and food plants of butterflies.
References
- Swaay, C. van, R. Ketelaar en D. Groenendijk (2002). Dagvlinders en libellen onder de meetlat: jaarverslag 2001. Rapport VS2002.010. De Vlinderstichting. Wageningen.
