De Rouwmantel, ooit algemeen, nu zeldzaam

Nymphalis antiopa was once a butterfly found regularly in the Netherlands. In the 1960s there was a sudden decline of the species and now the only specimens observed are wanderers. The cause of this sudden decline has not been disclosed. Data show that cool summers and severe winters had a negative effect on the occurrence of N. antiopa. However, a consistent correlation could not be found. Though not being the only factor, bad weather conditions could have been an Important factor contributing to the disappearance of the butterfly species.