Butterfly, Moth and Dragonfly Surveys

Background

Butterflies, day-flying moths and dragonflies are popular and attractive insects, and also a highly visible addition to any wildlife area. Successful management to maintain or encourage these beautiful insects onto a site provides obvious and enjoyable benefits in conservation or recreation areas. Several of these insect species are listed as Priority Species in the UK Post-2010 Biodiversity Framework, a list of those species designated as priorities for national conservation strategies.

Butterflies are generally considered to be good indicator species, as they are particularly sensitive to subtle changes in habitat or climate, therefore butterfly surveys are a straightforward and very useful tool in determining the success of management on a site and in influencing its future management.

An increase in obvious and charismatic species such as butterflies, dragonflies and bumblebees will often greatly improve the perception of the ‘wildness’ of a site.

Timing

The optimal period for Butterfly, Moth and Dragonfly Surveys is May to mid-September. Surveys can be carried out in April and late September to early October, but the adults of many species will not be present at this time so additional surveys within the optimal period are generally required to provide a complete picture of the species present.

Methodology

Our surveys are usually carried out by walking a set number of transects. EMEC Ecology uses the method which forms the basis of the UK’s Butterfly Monitoring Scheme (BMS). This involves the surveyor counting the numbers of each species of butterfly seen 2.5m either side and 5m in front whilst walking at a steady pace along the transect in weather suitable for butterfly activity. This has been shown to be an accurate method of assessing change in butterfly distributions and population size over time. EMEC Ecology’s dragonfly surveys follow the methodology developed and used by the British Dragonfly Society.

Following the Survey

Following the invertebrate survey results, specific advice suitable for the proposed works and the species found can be provided. This may include advice on suitable planting schemes in order to encourage specific species, or specific management regimes and timings of the work to promote diversity.

Examples

EMEC Ecology invertebrate ecologists are experienced in carrying out butterfly, day-flying and night-flying moth and dragonfly surveys. Our clients currently range from individual landowners, farmers and small to medium sized businesses, up to large multi-national companies and government agencies, including Natural England.

Recent and long-term ongoing surveys include:

• Long-term monitoring of the butterfly populations of a grassland site for a major retail and manufacturing company.
• Butterfly surveys of an active power station to determine the presence of UK Post-2010 Biodiversity Framework species on the site.
• Evening moth trapping for county rarities as part of an on-going management plan for a major holiday company.
• A dragonfly survey at a site near Newark-on-Trent to determine if the locally rare golden-ringed dragonfly was present within the vicinity of proposed floodbank works.
• Habitat assessment surveys to determine the suitability of a site for the marsh fritillary butterfly.
• Habitat assessment of a brown field site to determine if the small blue butterfly was likely to be present.