大象传媒

Regular migrants like the Painted Lady and Clouded Yellow butterflies are seen most years, but in wildly variable numbers. Some butterflies we think of as residents, like Large White and the Red Admiral, are also migratory and their numbers are boosted by fresh arrivals in summer.

During the remarkable invasion of Camberwell Beauty in 2006, landfalls were spread along the coast more evenly from Norfolk through Suffolk to Essex, but one of the first sightings was on the Shotley peninsula.

Grayling, Butterfly Conservation

Habitat

An analysis of records for the period 1995-2007 shows that the average tetrad (2km square) of Suffolk hosts 18 butterfly species. Landguard Point, Felixstowe has 28, Pipers Vale and Trimley Marshes 26 each - all better than average.

Partly this is due to the migrants, but also because those places have nice butterfly habitat. Recently arrived migrants are seeking wild territory with the right food plant for them to lay eggs on.

In the case of the Painted Lady, this larval host plant is thistle, which is abundant almost everywhere.

The Clouded Yellow, on the other hand, is looking for the crop lucerne, which is no longer grown as widely as it was 20 years ago, so mostly they have to settle for clover, which is less satisfactory, but more easily found.

Wall, Butterfly Conservation

Urban development comes down to the coast at Felixstowe and Harwich, inviting butterflies to continue upriver, and the wild margins of the Orwell are听an attractive buffer zone when compared to the agriculture inland.

Decline

Two of our relatively scarce resident species are the Grayling and the Wall. Both of these favour coastal areas, and have declined inland over the past decade. Their little cousin, the Small Heath, is declining in a similar way, but also remains common in many stretches of low-fertility grassland along the Orwell.

As long as the estuary margins retain their wild quality, these three species will do well here, whilst declining in high Suffolk.