2007- Best Ever Year for Large Blue Butterfly at Collard Hill
02/04/2008 10:43:26Large Blue Open Day 2008
- The 2008 Large Blue open day at Collard Hill in Somerset will take place on Sunday 22 June 2008 between 10am-5pm. The Large Blue Hotline number is 01793 817732.
February 2008. 2007 was the most successful year for the rare Large Blue butterfly since it’s re-introduction at the National Trust’s Collard Hill in Somerset in 2000. More than 350 butterflies were recorded during the flight season, easily surpassing the previous highest number.
Long Flight season Despite the Rain
The summer of 2007 was the longest flight season on record for the Large Blue butterfly at Collard Hill – the first butterfly was seen on the 2 June, the earliest recorded sighting, and the flight season lasted thirty-three days. The warm spring helped the caterpillars develop fast and butterflies made the most of some good early June weather, and laid a staggering 8,840 eggs – before the late June deluge.
Matthew Oates, Nature Conservation Adviser for the National Trust and leading butterfly experts, says, ‘Despite the poor summer 2007 was a remarkable year for the Large Blue at Collard Hill. It saw record numbers of butterflies in flight and it was the earliest and longest fight season since its re-introduction.’
The summer of 2007 was the longest flight season on record for the Large Blue butterfly at Collard Hill – the first butterfly was seen on the 2 June, the earliest recorded sighting, and the flight season lasted thirty-three days. The warm spring helped the caterpillars develop fast and butterflies made the most of some good early June weather, and laid a staggering 8,840 eggs – before the late June deluge.
Matthew Oates, Nature Conservation Adviser for the National Trust and leading butterfly experts, says, ‘Despite the poor summer 2007 was a remarkable year for the Large Blue at Collard Hill. It saw record numbers of butterflies in flight and it was the earliest and longest fight season since its re-introduction.’
Lifecycle of the Large Blue butterfly
- The Large Blue begins life as a normal caterpillar and the young larvae feed on wild thyme flowers. From then on, its life depends on an elaborate con-trick. As each larva drops to the ground, it secretes a sticky sugary substance which ants can't resist. The ants are, in fact tricked into thinking that the larva is a lost ant grub and take it into their underground colony. But not any old ant will do, only large colonies of a single species of red ant, Myrmica sabuleti, can act as a suitable host. An incredible phase in the caterpillar’s life then begins where for ten months it turns into a carnivore – feeding as a parasite on the ant grubs having conned the hapless ants into thinking it is harmless. The caterpillar then pupates in the ant nest, and the butterfly crawls out of the ant tunnels finally emerging for a few brief days in the last stage of its remarkable life as a beautiful butterfly. These final days - which for a few weeks this summer the public will be able to see at Collard Hill - are a frantic struggle to find a mate and for the females to lay their eggs on the wild thyme, in order for the cycle to begin again.
1979, Extinct in the UK
The Large Blue was re-introduced into the UK in the 1980s following its extinction in 1979. Collard Hill is the only accessible place where visitors can see this majestic butterfly during the height of summer. The National Trust manages three other sites in Devon and Cornwall where the Large Blue can be found, but access is difficult and butterfly numbers are low.
In recent years the Large Blue has spread across the Collard Hill site helping to reduce any pressure from visitor numbers. A special open day is held in June every year at Collard Hill where National Trust wardens and volunteer wardens take visitors on tours of the site and tell the story of this remarkable butterfly.
Special Grazing Regime
A major factor in the success of the Large Blue story has been the grazing regime, run by local farmers George and Pat Burrough. Dartmoor Ponies and North Devon cattle have helped to create ideal habitat conditions for the butterflies, which have very particular requirements, to flourish. They graze the land between August and February and then return the animals in late April until late May to counter the main pulse of grass growth, removing the animals just before the butterfly emerges. This is essential to create the right conditions for the ants on which the Large Blue caterpillars feed.
Matthew Oates, continues, ‘Last year was a remarkable year for wildlife as the weather caused chaos and disruption. The National Trust has four Large Blue sites in the west of England and they were all affected in different ways by the dry spring and the very wet summer, but Collard Hill was a great success story. 2008 could and should be another record breaking year for the Large Blue at Collard Hill with a staggering number of eggs laid in 2007 and a grazing regime that is making the habitat even better.’
The Large Blue was re-introduced into the UK in the 1980s following its extinction in 1979. Collard Hill is the only accessible place where visitors can see this majestic butterfly during the height of summer. The National Trust manages three other sites in Devon and Cornwall where the Large Blue can be found, but access is difficult and butterfly numbers are low.
In recent years the Large Blue has spread across the Collard Hill site helping to reduce any pressure from visitor numbers. A special open day is held in June every year at Collard Hill where National Trust wardens and volunteer wardens take visitors on tours of the site and tell the story of this remarkable butterfly.
Special Grazing Regime
A major factor in the success of the Large Blue story has been the grazing regime, run by local farmers George and Pat Burrough. Dartmoor Ponies and North Devon cattle have helped to create ideal habitat conditions for the butterflies, which have very particular requirements, to flourish. They graze the land between August and February and then return the animals in late April until late May to counter the main pulse of grass growth, removing the animals just before the butterfly emerges. This is essential to create the right conditions for the ants on which the Large Blue caterpillars feed.
Matthew Oates, continues, ‘Last year was a remarkable year for wildlife as the weather caused chaos and disruption. The National Trust has four Large Blue sites in the west of England and they were all affected in different ways by the dry spring and the very wet summer, but Collard Hill was a great success story. 2008 could and should be another record breaking year for the Large Blue at Collard Hill with a staggering number of eggs laid in 2007 and a grazing regime that is making the habitat even better.’
