Tuesday 20 August 2002
3,500 British field crickets released back into the wild
On Wednesday 21st August 2002, the Zoological Society of London (ZSL) of which London Zoo is part, and English Nature, will be releasing 3,500 captive bred British field crickets (Gryllus campestris) back into the wild. The release will take place at two locations as part of an ongoing project to preserve the species in the wild.
The capture-bred crickets will be released at a secret location in West Sussex and at Shortheath Common in Hampshire, part of the local council nature reserve. Shortheath Common already has a healthy population of London Zoo bred British field crickets that can be heard singing in the summer following an earlier release into the wild in 2000. This year's release will be to re-inforce numbers.
In the late 1980s, the British field cricket population was down to less than one hundred individuals in a single colony in West Sussex. Then in 1991 it was estimated that without action these indigenous insects would have died out within six years. The species was included in the English Nature Species Recovery Programme by Dr David Sheppard, an Invertebrate Ecologist for English Nature, with the aim of creating six new colonies in sites around Southern England.
Initially eggs were raised from a handful of wild caught crickets by the Web of Life team, London Zoo's biodiversity centre. This will be the fourth year a release of British field crickets has taken place following the great success of the previous re-introductions. After the first release of 3000 crickets in 1991 a number of colonies have successfully established themselves amongst the short grasses and chalky/sandy soils found within the South East of England.
The Zoological Society of London has conducted thorough testing of the British field crickets to ensure that all the individuals are healthy when they are released. This is an essential process when re-introducing captive-bred animals to their natural habitat, as it reduces the risk of introducing diseases that could threaten resident populations. ZSL is also involved in vital investigations to identify the amount of remaining genetic variation in the British populations of field crickets compared with continental populations.
Visitors to London Zoo can visit the Web of Life exhibition itself, where many endangered species of invertebrates are bred. The specially prepared outside enclosures and glass fronted breeding rooms allow visitors to watch the keepers as they work to save endangered species such as the British field cricket and the Partula snail.
Notes to Editors:
British Field Cricket Facts
- Length: 17-23mm
- Habitat: Short tussocky grass and bare ground, which may be grazed by farm animals or rabbits, on chalky or sandy soils in the south-east of England.
- Food: Omnivores, feeding mainly on wild grasses.
- Threats: Modern farming methods in Britain have resulted in the loss of suitable management of heath grassland and down-land, with grassland
becoming too tall and dense, or being invaded by bracken and scrub.
- ZSL is involved in the re-introduction of other UK species including the dormouse, barbary moth, wartbiter cricket and red kites.
- Founded in 1826, the Zoological Society of London (ZSL) is an international scientific, conservation and educational charity: our key role is the conservation of animals and their habitats. ZSL runs London Zoo and Whipsnade Wild Animal Park, carries out scientific research in the Institute of Zoology and is actively involved in field conservation in other countries world-wide.
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