With a population apparently in decline across the UK, as well as many other parts of Mainland Europe, what are the main threats to the Stag Beetle?
STAG BEETLES AND THEIR PREDATORS...
Despite looking relatively tough, Stag Beetles are a tempting prospect for a number of predators. Their abdomens contain a fat store that maintains them across their life span, making them a highly nutritious snack .
Studies on predation of adult beetles carried out across Europe show that corvids (birds such magpies, crows, and jackdaws) are the biggest predators of Stag Beetles. in the UK populations of Magpies and Carrion Crows have both increased over the past decade, which may be having a knock-on effect on Stag Beetle populations.
These birds often have a signature style when it comes to feeding on Stag Beetles, taking only the fat filled abdomen, and leaving the rest of the beetle, including the elytra (wing cases) intact. You may find beetles still crawling around in this state, damaged beyond any chance of recovery.
Foxes also score high in the predator league table – they will often gulp down the whole beetle, and you can sometimes find traces of the un-digestible parts of the beetle, such as the wing cases, in the fox’s faeces. Hedgehogs will also happily munch away on a Stag Beetle. Domestic cats may also pose a threat to the beetles.
Aside from corvids, avian predators include woodpeckers, some species of owl, and other birds of prey such as kestrels.
Even buried deep underground the larvae aren’t totally safe from predators either. Badgers have been known to dig up larvae to eat, and, whilst there isn’t much overlap in their native ranges in the UK, in parts of Europe Wild Boar are also known to feed on Stag Beetle larvae.
THE BIGGEST THREAT...
Whilst all the animals mentioned above do have a certain impact on Stag Beetle populations, the greatest threat to its continued survival across the UK and Mainland Europe, according to the vast majority of the researchers currently working with the beetle, is man.
Some of the threat that man poses to the Stag Beetle is direct. Particularly in the UK where the beetle favours urban areas, it is not uncommon to find Stag Beetles dead on the road having been crushed by cars, or squashed underfoot on pavements. Misguided fears that the beetle is somehow dangerous lead some people to deliberately kill the beetles too.
However, the main threat comes from destruction of habitat. Stag Beetles rely on dead and decaying wood as part of their life cycle. Eggs are laid near dead wood, and the larvae feed on it as they grow. Tidying of gardens, development taking over open spaces, and certain forestry management techniques are all responsible for the removal of the dead wood that is so crucial to the survival of the species into the future.