Transect walks are done to monitor butterflies at a certain site. Most are walked once a week for 26 weeks, April to September, by a team of walkers. Some are targeted at certain species, and are only walked when the target species is on the wing, while others attempt to monitor across an area, such as the Purbeck Ridge.

The spreadsheets of results linked here cover the 26-week transect walks. They give the total results for each species of butterfly counted in the walking season at each transect. Some cells are coloured in:

• RED indicates that numbers for the species at this transect increased by over 50% of both its total count the previous year and its average count since 2013.
• YELLOW shows that numbers for the species at this transect increased by more than 50% either on its total count the previous year or its average count since 2013.
• BLUE indicates that numbers for the species at this transect decreased by over 50% of both its total count the previous year and its average count since 2013.
• GREEN shows that numbers for the species at this transect decreased by more than 50% either on its total count the previous year or its average count since 2013.

Spreadsheets prior to 2021 also have BROWN cells showing the species at this transect was more than 50% up on the previous year’s figure but over 50% down on its average.

Annual results

• 2021 transect walk results

As of March 2022 we are working backwards putting up these sheets, so please bear with us while we get it all done.