Stag Beetles: the Jaws of the forest floor
There are over 1,200 species of these big-jawed critters in the world, and maybe even more than 85 different species just in Australia, but even though there are lots of different types of Stag Beetle some in great danger.
Stag Beetles love to live in damp woodland areas with lots of leaves and rotting wood on the ground, but unfortunately, these are also the kinds of areas that humans like to clear for houses, farming or to use for logging.
Male Stag Beetles are easy to recognise because they have a great big jaw, like a pincer. The females can be a little trickier to spot. Many types of Stag Beetle are brown or black, but there are also a few really beautiful species, like the Rainbow Stag Beetle, that are very colourful.
You can help look after Stag Beetles in your Backyard
The Stag Beetle is a great friend to humans, playing a really important role in ridding forests and our gardens of rotting leaves, fruits and wood, so it’s really important to do what we can to protect them.
Baby Stag Beetles are plump, c-shaped, cream coloured grubs, like most of their scarab beetle relatives. But you can tell if the baby scarab you find is a Stag Beetle by looking at its lower back. If it has two dark, hard, oval-shaped pads on its back, it’s most likely a Stag Beetle baby.
Adult Stag Beetles vary in size depending on their species. Some are just under a centimetre in length, others grow to around 6 cm long. You will most likely find them making a home for their babies in rotten logs and trees or underneath layers of moist leaves on the ground.
Be a Backyard Buddy
Stag Beetles’ jaws can be big and imposing, but they are also really fascinating. They are not at all like human jaws that chew up and down, instead they move sideways. Even more interesting, their jaws are not used for chewing. In fact, most adult Stag Beetle species don’t eat much but a very rare treat of nectar, sap or young tree shoots. Many types of Stag Beetle don’t eat anything at all once they hatch as adults.
So why have such big jaws if they’re not for eating? Male Stag Beetles use their big jaws to wrestle with other male Stag Beetles, especially when a female is nearby or they have stepped into someone else’s territory. It’s how the beetle got its name; they use their jaws like a male Red Deer, or stag, uses its antlers to show off and fight.
Stag Beetles love:
- Thick, damp layers of leaves and organic material left on the ground.
- Rotting logs and fungus.
- A little sap or nectar from time to time.
But they don't like:
- People or fires destroying their habitat.
- Other Stag Beetle stepping on their turf.
- Being moved away from their territory.
Be a Buddy to Stag Beetles
- Leave a Stag Beetle where it is if you find one in the wild or your backyard. Some Australian Stag Beetles are very rare so it is important that we leave them to have families in the places they choose. They know where the best place is to lay their eggs and care for their babies.
- Plant a few local deciduous trees in your garden. Stag Beetles love the leaf litter created each autumn, especially by trees like Red Cedars and Illawarra Flame trees. The deeper the layers of leaves, the happier Stag Beetles will be.
- Leave rotting trees or branches on the ground, or place a few hollow rotting logs near a pond or water source in your yard. These make fantastic places for Stag Beetle babies to grow. In return for your generous offer of a home, they will help you by eating all of the rotten wood and turning it into great fertilizer for your soil. That’s a pretty good deal.
- Using firewood or wood products that come from old growth forests. Old growth forests provide the perfect habitat for some of our most threatened species of Stag Beetle.
- Getting a pinch. The large jaws of some Stag Beetles aren’t just for fighting: they can also give humans a painful pinch if the beetle feels scared. Although they are not normally aggressive towards humans, it is best to approach these beetles with a little caution.
- Disturbing Stag Beetle grubs. Stag beetles stay in their larval stage (as grubs) for two or three years. This time is spent collecting all of the energy the beetle needs to grow into an adult and storing all of the energy that it will need for its whole adult life too. That’s a whole lot of eating and storing for a little grub to do.
Don't be surprised if Stag Beetles:
- Are hard to find, even with the perfect habitat in your backyard. Stag Beetles prefer to live in woodland habitats that haven’t been damaged by people or forest fires for over fifty years. If you do find one in your yard, it is a pretty special visitor to have.
- Don’t fly away. Some Stag Beetles can’t fly even though they have wings. Over time, some species have evolved so that their wings are fused closed over their bodies. Other species that live in tropical areas find it hard to fly when it gets too cold. If you find a Stag Beetle that doesn’t fly, it’s all the more reason to protect it because many of the threatened Australian species are the ones that have lost the ability to fly.
A few more Stag Beetle facts
Stag Beetle profile:
- Some male Stag Beetles can live for two summer seasons.
- As part of the International Year of Biodiversity, the City of London ran a competition to design luxury ‘hotels’ for endangered insects, such as Stag Beetles, to be built in its public parks and gardens. Click to see some of the winning designs.
- It is illegal to collect or remove some species of Australian Stag Beetle from the wild because they are so rare. The Broad-toothed Stag Beetle, which is found in south-eastern Tasmania, for example is an endangered species. Click to learn more about Australia’s rarest Stag Beetles and where they live.
- Stag Beetles are nocturnal and they sometimes become attracted to bright outside lights, especially on warm nights.
- Not all species of Stag Beetles are threatened, and there are some you can even keep as pets. If you are interested in a Stag Beetle pet, do not collect one from the wild; buy one from a reputable pet store and always check which species are protected first. Then you know you are not illegally buying a threatened species. Click to learn about keeping and breeding Rainbow Stag Beetles as pets.
- Click to see an amazing image of a Stag Beetle taking off in flight.