Big Butterfly Count in UK begins with eyes on declining numbers

The launch of the world's largest insect survey will test the disappearance of butterflies this summer.

People are being urged to take part in the Big Butterfly Count in order to find out if anecdotal reports of a lack of butterflies reflect a wider reality across Britain this summer.

There were more than 150,000 butterfly counts submitted last year. The citizen science survey has recorded the lowest average number of butterflies since it began in 2010 at nine per count.

More and more people are doing the count, but fewer and fewer butterflies are being seen by them.

Half of Britain's 58 resident butterfly species are listed as "threatened" or "near threatened" with extinction according to the latest Red List. Butterflies are declining at a faster rate in urban areas than in the countryside.

Dave Goulson, a scientist, has been sharing his observations of insect-bereft buddleias. Buddleias aren't festooned with butterflies until late summer when there isn't much else to eat.

The recent declines in butterfly abundance recorded by the Big Butterfly Count may be due to species emerging significantly earlier in the summer because of global heating.

After 13 years of data collected by the UK Butterfly Monitoring Scheme, the scientists at ButterflyConservation will analyse the data to see if the observations tally with seasonal variations picked up by a longer term scientific count. In the future, the Big Butterfly Count could be moved to earlier in the summer to take advantage of the earlier emergence of butterflies.

The small tortoiseshell, a buddleia-feeding butterfly, has seen a decline in its numbers.

The data shows that it is doing better in north Wales, Northern Ireland and Scotland than it is in south England.

She said that the data gathered through the Big Butterfly Count can be used to understand why that might be happening. The butterfly is emerging earlier in the south and being between broods when the count takes place.

The benefits for people taking 15 minutes out of their day to observe and record butterflies in a park, wood or garden is one of the things that ButterflyConservation is trying to convey.

Spending time in nature is good for our mental health. A short amount of time in the natural world can relieve stress and help us feel better.

Watching butterflies for 15 minutes can be very relaxing. It's good for you and good for butterflies if you help collect the data they need to protect them. It is a win-WIN situation for everyone.