Big Butterfly Count: help experts establish why numbers are falling

Butterfly numbers plummet in adverse weather

Big Butterfly Count
Take part in the Big Butterfly Count – ends this Sunday

Have you noticed what a bad year for butterflies it is? There’s been a ‘perfect storm’ of a sunless summer, cool spring and mild winter, which may make 2016 the worst year for butterflies since records began.

There’s usually a healthy population of large and small whites (cabbage whites to you and me), small tortoiseshells, peacocks and the odd red admiral. This year, I’ve seen no peacocks since May, no tortoiseshells or red admirals at all and only a few of the whites.

On the other hand, there are loads of moths – diamondbacks – which appeared in 100 times the normal numbers from continental Europe in June. They are resistant to many insecticides and feed on brassicas and oil seed rape. Their offspring should be appearing about now, so net your cabbages.

Red admiral
Red admiral on Buddleja, August 2015

Another migrant to look out for is the silver Y moth, spotted in its thousands in the Euro 2016 final (one landed on Cristiano Ronaldo’s face). They will be blown into Britain by southerly winds.

Sir David Attenborough is urging people to take part in the Big Butterfly Count, a nationwide survey aimed at assessing the health of our environment.

It was launched in 2010 and is the world’s biggest survey of butterflies. More than 52,000 people took part in 2015, counting over 580,000 individual butterflies and day-flying moths across the UK.

The worst year since records began in 1976 was during the cold summer of 2012. Many common species, particularly the small and large whites, the common blue and the small copper are scarce this year. There’s also been a dip in the number of meadow browns, which was third in 2015, with 76,713 spotted.

Experts fear that increasingly mild winters are harming populations – caterpillars which usually hibernate were seen emerging during the mild December of 2015, and were then likely to starve or be killed off by cold weather.

All you have to do is count butterflies for 15 minutes during bright (preferably sunny) until the survey ends on Sunday, August 7.

Large white butterfly
Large white (cabbage white) on Buddleja. Picture courtesy of RHS

If you are counting from a fixed position in your garden, count the maximum number of each species that you can see at a single time. If you are doing your count on a walk, then total up the number of each butterfly species that you see during the 15 minutes.

There’s an identification chart to download to help you work out which butterflies you have seen.

You can submit separate records for different dates at the same place, and for different places that you visit – and the count is useful even if you don’t see any butterflies or moths.

Send in your sightings online at or by using the free big butterfly count smartphone apps available for iOS and Android.

The count is also backed by Alan Titchmarsh, Mike Dilger and Nick Baker, vice-presidents of Butterfly Conservation and Joanna Lumley.

For more details, visit

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