Summary
Butterfly numbers in the UK show mixed trends, with some species increasing due to warmer weather and conservation, while many others are declining because of habitat loss. The long-running UK Butterfly Monitoring Scheme has tracked these changes over 50 years using millions of volunteer records.
Key Facts
- The UK Butterfly Monitoring Scheme has collected over 44 million records from more than 782,000 surveys since 1976.
- Of 59 native butterfly species, 33 have declined, 25 have increased, and one has insufficient data.
- Warmer weather linked to climate change has helped species like the Orange Tip and Red Admiral butterflies increase their numbers.
- Conservation efforts have helped rare butterflies like the Black Hairstreak and Large Blue recover.
- Butterflies that live in many types of places, such as parks and gardens, tend to do better than those needing special habitats like chalk grasslands.
- Some species have seen large declines, such as the white-letter hairstreak (down 80%) and the pearl-bordered fritillary (down 70%).
- The small tortoiseshell butterfly, once common, has declined by 87%.
- Volunteers have walked over 932,000 miles at more than 7,600 sites to collect data over the past decades.
