A precipitous decline in the number of moths in Britain is the latest sign the natural world is rapidly deteriorating, a new report warns.
Britain’s moths have declined by one-third in the last 50 years with the south of the country recording lower numbers than the north.
The report by the charity Butterfly Conservation said various kinds of human activity were the key reasons for the decline, with habitat destruction, chemical pollution, artificial light and the climate crisis considered the major causes.
The report found the total abundance of larger moths in Britain decreased by 33 per cent over the 50 years between 1968 to 2017.
Across the southern UK the researchers found a 39-per-cent decrease in moths, while in the north, numbers were down by 22 per cent.
The decline in moths in the north illustrates how the outlook for moths has deteriorated, the report said, as the trend was not apparent when the data was last examined in 2007, at which point losses were only recorded in the south.
Dr Richard Fox, associate director of recording and monitoring at Butterfly Conservation and lead author of the report, said: “This decline is worrying because moths play a vital role in our ecosystems. They are pollinators of many plants, with some wildflowers, such as orchids, relying on visiting moths for reproduction.
“They also provide essential food for thousands of animal species, including bats and many familiar birds.
“We’re lucky enough to have almost 900 species of larger moths in Britain. Because moths are dwindling, we can be pretty sure that other wildlife are also in decline and that our wider environment is deteriorating.”
Climate change has had a pronounced effect on moths, the researchers suggested.
Warming climates mean species which have tended to live in southern regions have expanded further northwards, while rising temperatures have also caused declines for moths that are adapted to cooler climates.
For some species this has resulted in catastrophic declines – the grey mountain carpet moth which can be found on uplands across the UK has seen an 81-per-cent decrease in distribution.
The researchers said halting or reversing species decline was an enormous task, but not impossible, and their report highlighted examples of conservation success for rare and threatened moths.
Dan Blumgart, quantitative moth ecologist at Rothamsted Insect Survey, said: “Comparing this latest State of Britain’s larger moths to the first edition in 2006, it is a disappointment that the situation has not improved.
“It is clear that a much bolder policy of habitat protection and restoration will be needed if British moths are to thrive well into the future.”