Effects of timing and frequency of mowing on the threatened scarce large blue butterfly – A fine-scale experiment

Published source details Kőrösi A., Szentirmai I., Batáry P., Kövér S., Örvössy N. & Peregovits L. (2014) Effects of timing and frequency of mowing on the threatened scarce large blue butterfly – A fine-scale experiment. Agriculture, Ecosystems & Environment, 196, 24-33.
Share Tweet Email

Actions

This study is summarised as evidence for the following.

	Action	Category
	Reduce cutting frequency on grassland Action Link
	Delay cutting or first grazing date on grasslands to create variation in sward height Action Link
	Cease mowing on grassland to allow early succession Action Link

Reduce cutting frequency on grassland

A replicated, randomized, paired, controlled study in 2007–2010 in four meadows in Őrség National Park, Hungary (Kőrösi et al. 2014) found that grassland mown once/year had a similar abundance of scarce large blue butterflies Phengaris teleius to grassland mown twice/year, but a higher abundance than abandoned, unmown plots. Three years after management began, the number of scarce large blue butterflies in plots mown once/year in May (0.86 individuals/plot/day) or September (0.94 individuals/plot/day) was similar to the number in plots mown twice/year (0.70 individuals/plot/day). All mown plots had more butterflies than abandoned plots (0.28 individuals/plot/day). In May 2007, four meadows were each divided into four equal-size plots, and one of four management regimes was randomly applied to each plot. Three plots/meadow were mown for four years, either once/year in May, once/year in September, or twice/year in May and September, all with cuttings removed. The fourth plot in each meadow was abandoned (not mown). In July 2007 and 2010, butterflies were surveyed for five minutes, 15–20 times/year, in each of three or four 20 × 20 m squares/plot.

(Summarised by: Andrew Bladon)
Delay cutting or first grazing date on grasslands to create variation in sward height

A replicated, randomized, paired, controlled study in 2007–2010 in four meadows in Őrség National Park, Hungary (Kőrösi et al. 2014) found that grassland mown in September had a similar abundance of scarce large blue butterflies Phengaris teleius to grassland mown in May, and that numbers decreased in May-mown grassland but remained stable in September-mown grassland. Three years after management began, the number of scarce large blue butterflies in plots mown in September (0.94 individuals/plot/day) was similar to the number in plots mown in May (0.86 individuals/plot/day). However, the number of butterflies in September-mown plots was similar to the first year of management (1.21 individuals/plot/day), whereas the number in May-mown plots was higher in the first year of management (1.64 individuals/plot/day). In May 2007, four meadows were each divided into two equal-size plots, and one of two management regimes was randomly applied to each plot. For four years, one plot/meadow was mown annually in May and the other was mown annually in September, all with cuttings removed. In July 2007 and 2010, butterflies were surveyed for five minutes, 15–20 times/year, in each of three or four 20 × 20 m squares/plot.

(Summarised by: Andrew Bladon)
Cease mowing on grassland to allow early succession

A replicated, randomized, paired, controlled study in 2007–2010 in four meadows in Őrség National Park, Hungary (Kőrösi et al. 2014) found that abandoned grassland had fewer scarce large blue butterflies Phengaris teleius than mown grassland. Three years after abandonment, the number of scarce large blue butterflies in abandoned plots (0.28 individuals/plot/day) was lower than in plots mown once/year (0.86–0.94 individuals/plot/day) or twice/year (0.70 individuals/plot/day). In May 2007, four meadows were each divided into four equal-size plots, and one of four management regimes was randomly applied to each plot. Three plots/meadow were mown for four years, either once/year in May, once/year in September, or twice/year in May and September, all with cuttings removed. The fourth plot in each meadow was abandoned (not mown). In July 2007 and 2010, butterflies were surveyed for five minutes, 15–20 times/year, in each of three or four 20 × 20 m squares/plot.

(Summarised by: Andrew Bladon)