Zoë Randle from Butterfly Conservation highlights why butterflies are so important for farming and wildlife on farmland and recommends the RSPB Farmland Butterfly Survey method for monitoring them. This methodology is being used in the Volunteer Monitoring of Farm Wildlife project which will enable farmers to understand the wildlife on their farms and how to best manage habitats for them.

Image: (c) Butterfly Conservation 

Butterflies are indicators of a healthy environment and healthy ecosystems. Areas rich in butterflies and moths are rich in other invertebrates. These collectively provide a wide range of environmental benefits, including pollination and natural pest control. Find out what butterflies are on your farm by using this simple method to monitor their numbers.

Butterflies are the best-studied UK insects by far, providing vital insights into the changing state of wider biodiversity and the ecosystem services, such as pollination, that depend upon it. Across the UK butterflies are declining, overall 76% of the UK’s resident and regular migrant butterfly species declined in either abundance or occurrence (or both) over the past four decades. Most worryingly, several species of widespread butterflies, such as those found on farmland are among those that are declining most rapidly. This is of great concern not just for butterflies but for other wildlife species and the overall state of the environment.

Environmental conditions are deteriorating for the majority of species, which is likely to reflect a decline of other widespread insects, having knock-on impacts for animals further up food chains.

How healthy is your farm for butterflies?

We have developed a simple method to enable farmers, or volunteers from the RSPB’s Volunteer Monitoring of Farm Wildlife, to monitor the butterflies on their farms. In addition to this, the data collected from farmers and or volunteers will contribute to the National (UK) recording scheme for butterflies - Butterflies for the New Millennium (BNM).

How do I count the butterflies on my farm?

All you need to do is undertake a 15-minute count in five different parts of the farm on a fortnightly basis from mid-May to the end of August. A minimum of five visits is required, although move visits are welcomed. Subsequent counts should be done in the same five places on the farm.

Butterflies are fair weather creatures, so you need to ensure that the weather conditions are suitable for butterfly activity. Before doing your counts, please ensure that the weather is dry, the temperature at least 13°C in sunny conditions, or at least 17°C when cloudy and windspeed is lower than 5 on the Beaufort scale (Fresh Breeze - Small trees in leaf begin to sway). Counts should ideally be made between 10:45 and 15:45 hours, although counts will be accepted from between 10:00 and 17:00 hours, providing weather conditions are suitable for butterfly activity.

During each 15-minute count you should pace yourself evenly across the area to be surveyed and count all butterflies close enough to be clearly identified but try to avoid double counting where possible (e.g., when an individual butterfly repeatedly flies in and out of your immediate vicinity, only count it once). Try to keep moving in one direction and do not count butterflies behind you. Take a consistent approach between each sampling occasion.

Image: (c) Butterfly Conservation 

Your counts can be logged via the RSPB Farmland Volunteer Butterfly Survey activity that has been set up in iRecord (www.brc.ac.uk/irecord). If you have the iRecord smartphone app you can link the activity to your phone and log counts in the field as you go using the General Survey mode within the iRecord app. If you do not have a smartphone you can use the RSPB Farmland Volunteer Butterfly Survey recording form and submit your counts via the RSPB Farmland Volunteer Butterfly Survey activity on your computer when you return from the field.

For further information on getting involved in the Volunteer Monitoring of Farm Wildlife please contact farmsurveys@rspb.org.uk.
Other resources:
Butterfly Conservation
Butterflies for the New Millennium Recording Scheme