Marsh Fritillary - Monitoring and Indicators of Success

Monitoring and Indicators of Success

• The frequency of larval webs in 3m strip can be counted during random walk of at least 100 paces in October - February. The larval web present in at least 30% of paces.
• Frequency of flowers (adult nectar sources) counted within 3m strip during random walk in May - June should be at least 50%
• Frequency of Succisa pratensis (larval foodplant) counted within 3m strip during a random walk of at least 100 paces. Succisa pratensis in at least 80% of paces. No more than 25% reduction in abundance
• Average height of sward measured by drop disc or by estimation. There should be a mosaic of sward heights of between 8 – 20 cm during May - September
• Sward structure monitoring. The butterflies require varied habitat structure: basking sites, supplies of nectar, roosting area.