Study shows short-term rise in butterfly numbers

Despite the rise, climate change is still a threat to butterfly populations.

A new report has found that many butterfly species are flourishing in Scotland – but this trend is likely to be short-lived without measures to reduce the effects of climate change.

This surge will probably not continue with the increased frequency of drought and fires, leading to the death of adult butterflies as well as the plants on which their caterpillars feed.

Areas rich in butterflies and moths provide many benefits, including pollination and natural pest control. Butterflies and caterpillars are also an important element in the food chain as prey for birds and bats and other animals.

In addition, due to rapid and sensitive response to subtle habitat or climatic changes, butterflies are useful indicators of environmental change.

The latest Scottish Biodiversity Indicator published by national agency NatureScot examines the long-term trend for butterflies since 1979. It finds that, from 1979 to 2021, there has been an increase across all species of 43 percent.

Of the 20 species analysed, nine have increased significantly and two have decreased. The remaining nine show no significant change.

The largest increases were in red admiral, orange-tip and ringlet butterflies, with climate change and weather being the likely drivers of change. The two species showing significant declines are grayling and small tortoiseshell butterflies.

Some populations are also continuing to shift northwards in response to climate change. Over the past 20 years, species traditionally found in the UK’s warmer southerly climes have become more numerous in Scotland.

Simon Foster, from Nature Scot, said: “Despite this short-term increase, we need to be working now to help butterfly populations deal with the increasing influences of climate change.

"Fortunately, there are easy things we can do to help. It’s wonderful to see many using wildflower seed mixes and we’re also working with partners to help butterflies and other pollinators thrive, from creating and managing habitat to promoting wildlife-friendly gardening and best practice guidance for developers.”

To find out more, contact Butterfly Conservation Scotland at [email protected].