February 20, 2006
British moths fall by a third in 35 years -study
By Chris Johnson
LONDON (Reuters) - The number of moths in Britain has
fallen by a third since the late 1960s, a study showed on
Monday, blaming the decline on destruction of the insects'
natural habitat, pesticides and climate change.
Conservation said 62 species of moths became extinct in the
20th century and many more varieties were now threatened or
Of the 337 moth species studied between 1968 and 2002, two
thirds showed a decreasing population trend and several fell
dramatically. One species, the brown Dusky Thorn which used to
be common in summer and early autumn, declined by 98 percent.
"These findings are shocking and a big wake-up call," said
Martin Warren, chief executive of Butterfly Conservation. "No
one suspected so many species were declining so rapidly.
"Moths are a key part of the food chain as most birds rely
on insects for part of their diet. For so many moths to
disappear shows a widespread and severe crisis for Britain's
In a preface to the report, "The State of Britain's Larger
Moths," naturalist and broadcaster David Attenborough said the
results of the study were "significant and worrying" as moths
were valuable indicators of what was happening in the British
"Although the precise causes of these losses still need to
be uncovered, the findings set more alarm bells ringing about
the extent of human impact on our environment," he said.
"Moths are important in food chains and their declines may
have significant knock-on effects on many animals, such as
birds bats and invertebrates."
Britain has around 2,500 species of moths, which are
closely related to butterflies. Most moths are nocturnal.
Scientists produced the study by collating as many as 8
million reports from volunteers operating night moth traps at
430 sites across Britain.
Warren said the exact reasons for the decline in moth
populations were unclear but some causes were easy to identify.
Half of Britain's ancient hedgerows, a key breeding ground
and reserve for many species of insects and birds, had been
destroyed since World War Two.
Moth population levels were also "strongly correlated" with
large-scale climatic changes with numbers decreasing after wet
winters and warm springs. Since the study began "climate change
has become evident," the report said.
Moths were also declining particularly quickly in urban
areas, which could be related to "light pollution" from
all-night lighting, a recent study has suggested.
"The prime suspects are habitat loss and climate change,"
Warren said. "We should stop using pesticides in our gardens,
leave rough areas and protect the countryside, especially wild
"Wildlife reserves could be built into new developments,"
he added. "There are all sorts of ways to help preserve British
wildlife. It is not rocket science."