May 2003

Butterflies along the boundary - Verdronken Land van Saeftinghe

Alex Wieland & Eddy Taelman

In the province of Zeeland lies the Verdronken Land van Saeftinghe, a salt marshland with an area of 3000 hectares. Few butterflies are seen here, in contrast with the sea dykes bordering the area. Butterflies were recorded along the 10 km sea dyke and on the 3 km Gasdam. The grassy vegetation on the sea dyke is monotonous, whereas that on the Gasdam is varied both in species and in structure. This difference is reflected by the butterfly species observed at the two locations. On the sea dyke and the Gasdam, there were large numbers of migrants such as the Red Admiral (Vanessa atalanta), Painted Lady (Vanessa cardui) and Clouded Yellow (Colias croceus). However, on the Gasdam, more species of resident butterflies were seen, that were also in larger numbers than on the sea dyke. Furthermore, on this ecologically more interesting site, a Small Heath (Coenonympha pamphilus) was sighted - a noteworthy observation.

Map Butterflies in Den Helder

Klaas Kaag

In the past half century, the range of the Map Butterfly (Araschnia levana) in the Netherlands has extended westwards, reaching the coast in 1983. In Den Helder, a coastal town in the province of Noord-Holland, one or two butterflies were sighted each year, until suddenly in 2001 there was a sharp increase in number. Caterpillars as well as butterflies were seen, of both the spring and summer generation. The numbers in 2002 were smaller than in 2001, probably due to bad weather and the unsuitable timing of mowing of the stinging nettles on which it breeds.
The phenology of the Map Butterfly was also studied. There was little difference between 2001 and 2002 in the appearance and duration of the life stages. The Map Butterfly is still a vulnerable species in Den Helder, and the mowing regime must be timed carefully to make sure that the butterfly does not disappear.

The Chequered Skipper on the Regte Heath

Liesbeth van Oirschot-Beerens

The Regte Heath is one of the richest butterfly areas in the province of Noord-Brabant. Of particular interest is a stable colony of the endangered species the Chequered Skipper, (Carterocephalus palaemon) that has established here. The habitat at the woodland edge, of patches of dry and partly moist heath, with abundant purple moor-grass (Molinia caerulea), or along sunny woodland paths with well-developed bramble scrub and purple moor-grass, is particularly well suited for the species. This article also describes the ecology and distribution of the Chequered Skipper. This butterfly is a rare species in the Netherlands, with only a few dozen colonies left. Fortunately, after a sharp decline in the 1980s, its numbers are now stable.

The Vosges, an inviting butterfly region

Resi Damhuis en Martin van den Berg

The Vosges in eastern France is said to be a region where 80% of the butterfly species of north-eastern Europe occurs. The authors give an account of a trip they made to the countryside between Epinal and
Colmar, where they saw a large number of interesting butterflies. The richly varied landscape each pocket with its own climate, leads to a great number of butterfly species with very different flight periods occurring in close proximity.