Reintroduction of extinct butterfly in Britain a lesson for animal conservationists

Washington, July 3 (ANI): The successful reintroduction of a once extinct butterfly in Britain has led scientists to determine that intelligent countryside management could improve the survival chances of animal and plant species threatened by climate change.This is the conclusion drawn by scientists at the Helmholtz Centre for Environmental Research (UFZ) from a British study on saving the Large Blue butterfly (Maculinea arion).

The Large Blue butterfly is rather rare throughout many European countries. This butterfly became extinct in Britain in 1979 and was reintroduced there 25 years ago.

Since then, the butterfly's reintroduction is seen as a model for the conservation of endangered insects.

The butterfly's survival depends on a large number of factors - as it belongs to the genus Maculinea.

This means that it is dependent not only on a specific food plant for the caterpillars, but also on a particular species of ant.

The caterpillars trick the ants into carrying them into their nest where they feed on the ants' brood through the winter.

However, this trick works only on one very specific type of ant - only Myrmica sabuleti is tricked by the scent of the caterpillars' of the Large Blue.

Other ants see through the disguise and remove any caterpillars that have been carried into their nest.

During the decline of the Large Blue in Britain, M. sabuleti ants were crowded out by a competing species of ant, M. scabrinoides, which copes better with lower soil temperatures.

"A change in the height of the grass by one or two centimetres can result in a two or three degree temperature change in the ants' brood chambers just below the surface," explained Professor Jeremy A. Thomas of Oxford University.

The soil temperature dropped because the meadows on which the butterflies and ants had lived together for so long were grazed less, and because an epidemic among the wild rabbits, which used to keep the grass short, caused their numbers to plummet.

A change in land use had thrown the sensitive interplay between the species off balance.

By the time this was realised, it was already too late for the Large Blue in Britain.

Eventually, butterflies were brought in from Sweden and the meadows were kept short in line with the scientific findings.

It was this that turned the reintroduction of the Large Blue into a success story.

There are now more butterflies of this highly endangered species living in the UK than there were when records began in the 1950s.

"The fact that it was possible to stop and reverse the decline could make this a model for many other insect conservation projects," said Jeremy Thomas. (ANI)