Starting Saturday, Butterfly Conservation wants volunteers to spend 15-minute periods determining how many butterflies they can spot, the Daily Express reported. The counting period runs through Aug. 5.
Sir David Attenborough -- possibly the world's best-known host of TV nature shows and the charity's president -- said the weather is likely to have interfered with the butterflies' life cycle by delaying their emergence. The period between April and June was the wettest ever in Britain.
"It isn't just rarities we're concerned about, it's equally or more important to know what's happening to our common butterflies -- and terrible things are happening," Attenborough said.