The State of Britain's Larger Moths

February 2013 saw the release of a new report in collaboration with Butterfly Conservation on the state of Britain's larger moths. Funded by the Esmé Fairbairn foundation, the report used data from the trap network - any trap with five or more year's worth of data was included - to assess the population trends of moths as a whole, and of the 337 species that were caught in enough numbers to analyse in the period 1968-2007.

See the Butterfly Conservation press release for more details, in summary:

  • across Britain, total abundance of moths has declined by 28%
  • this decline is more marked in the South with 40% declines recorded in southern traps (south of a line that can approximately be defined as Lancaster-York)
  • in contrast, no significant change is reported for northern Britain.
  • two-thirds of the 337 species have declined over the 40 year period
  • 37% declined by at least 50%
  • one third of species had increasing population trends with 16% more than doubling their numbers over the 40 years
  • the biggest losers - V-moth - 99% decline; Garden Dart - 98% decline; Double Dart - 98% decline; Dusky Thorn - 98% decline; Hedge Rustic - 97% decline
  • the biggest winners - Least Carpet - 74,000% increase; Blair's Shoulder-knot - 7,800% increase; Treble Brown Spot - 4,300% increase; Buff Footman - 3,900% increase; Scarce Footman - 3,500% increase

Many thanks to all the operators and identifiers, past and present, who have made this research possible, without your valuable input of time and energy we would not have been able to produce this report.

State of Britain's Larger Moths cover