Posted 25th May 2017 by Peter Byrne
Stag beetles are a 'protected species', which are listed on Schedule 5 of the Wildlife and Countryside Act 1981. The major threat to stag beetles in the UK is the removal of the larval habitat – this is predominantly dead wood. Even the removal of hedges and trees - both of which have dead portions under the ground, along with stumps, can cause habitat loss.
Why have they declined?
The main reason for the decline of the stag beetle has been the loss of their habitat. Many woodlands were sold for development during the inter-War years - just think of the suburbs built since the 1920's. The introduction of the green belt in 1947 did restrict suburban expansion but in the subsequent years, the majority of London's surviving open spaces have been developed, including many woodlands. This only continues to reduce stag beetle habitats, but an increase in awareness of their existence can help to defend beetles against developers.
The 'tidying up' of woodlands, parks and gardens has also seen the removal of dead and decaying habitats, a stag beetle larvae's food source. Tree surgery operations, such as the stump-grinding of felled trees, also remove a vital habitat for the beetle.'Tidying up' may still occur in gardens but woodland and park mangers are much more aware of the need to keep any dead and decaying wood to maintain the woodland ecosystem.
Predators, including cats, foxes and crows among others, could also have an adverse impact during the most vulnerable stage of the beetle's life cycle, when adults are looking to mate and lay eggs. This is largely natural predation but it has been suggested the rise in the number of magpies and carrion crows over the last decade could have had an impact on stag beetle populations.
Humans also pose a direct threat to the stag beetle - adult beetles will be attracted to warm surfaces such as tarmac and pavements, leaving them especially vulnerable to the risk of being squashed. Changing weather conditions also pose a risk - if it is especially dry or wet, it can affect the larvae, while wet and windy conditions can inhibit an adult beetle's flying ability.
Image courtesy of Bill Plumb / information courtesy of PTES