Falling populations: UK butterflies struggle with heatwave

Figures from conservationists show that last summer’s heat and drought has negatively impacted UK butterflies.

The UK Butterfly Monitoring Scheme (UKMBS) analysed data collected by volunteers last year which shows an average year as a whole for butterflies.

Many species delivered a good number of offspring in spring and early summer, but a decline was noted by late summer as drought killed plants used as food sources and nesting spots.

In addition to lower numbers last year, the UKMBS say there is concern over a knock-on effect this year.

With female butterflies unable to lay eggs and not enough food for caterpillars which did emerge in 2022, the overall reduction could lead to even fewer butterflies in 2023.

A number of species only produce one generation of offspring a year resulting in a heightened decrease particularly in grass-feeding varieties.

Of the species monitored, the small tortoiseshell saw its fourth worst year since monitoring began in 1976.

Around 4,000 volunteers worked to collect almost 600,000 records of butterflies across 2022.

Previous analysis from the UKMBS showed a decline in populations following droughts in 1976 and 1995.