It may sound a little macabre but, while you are out walking through the beautiful Dartmoor woodlands, how often do you turn your thoughts to the grisly job of burying a body? Alongside all the fascinating forms of woodland wildlife, there is a darker, morbid side, which is an essential part of the cycle of life. While springtime brings an abundance of new life, survival in the wild is a case of taking your chances when there are both winners and losers all the way along the food chain.
As a dormouse monitor, I have nest boxes set up around many of the local woods and these microcosms of life tell all sorts of stories from the uplifting successes of rare species battling against the odds, to the gory, gritty, real-life dramas that play out among the trees. Some of the small woodland songbirds perfectly illustrate the ups and downs in their battle for life and, in a good year, blue tit nests are a common springtime sight. Though they are not a rare bird, it is still a thrill to get a close-up view of their enduring efforts to raise their broods; there is nothing more endearing than a nest of newly feathered chicks getting ready to fledge. But, in a bad year, it can all seem quite gruesome. A few years ago, we experienced a sudden change in the weather. As the season was beginning to warm up, it quickly turned windy and the woods were soaked by deluges of rain. Within a matter of days, the developing nestlings were abandoned by their parents while they fought to preserve their own lives; food was scarce. All through the woods, the nest boxes were silent, with the corpses of tiny birds, decaying in their nests. The sense of despair was quite unpalatable.
This year though, has been a brighter one. With the added sunshine, the tiny chicks have been showing off their new and colourful plumage before leaving their nests in time for the dormice to appear in the boxes after their hibernation.
There are, of course, the odd exceptions. An occasional nest may get abandoned and we can only guess why that would be. The instincts of wild creatures to raise their young is so strong that they wouldn’t leave without a good reason, but one of the bird nests in my dormouse boxes had, surprisingly, been abandoned. Had the adults been predated by an owl? The chicks had quickly perished, but that was not the end of the story. This, for those of us that have a fascination for nature in-the-raw, was where it got really interesting. Approaching the box, a pungent smell was hanging around … it was the unmistakeable stench of decay. I had a good idea what was I was about to see when I opened the box and, as well as the sad sight of four little corpses, were flashes of bright orange, scurrying and burrowing around the nest. These were beetles from an amazing group of species called the “burying beetles”. Although they are quite common in the woods, they are seldom seen as they go about their job as undertakers, out of view and underground.
The Nichrophorus beetles are often referred to as “grave diggers” or “sexton beetles” and they perform their task with diligence. They can smell a rotting animal corpse from up to a mile away and immediately make their way to find it before any of their competitors do. Often working as a male-female pair, and with amazing strength, they drag the corpse of the bird down into the soil where the feathers are removed and the remains are formed into a ball. Here, the female beetle will lay her eggs and, when the larvae are old enough, they will feed on the carrion that was carefully provided by their parents. In a similar way, they will also recycle the corpses of other animals including mice and moles, many times their own size.
Whether you think this activity is suitable for the plot of a horror film, or a captivating role in nature’s work, it is a crucial part of tidying up the forest floor, recycling organic matter and returning nutrients to the woodland ecosystem. Without the burying beetles performing their vital link in the chain, we would be less likely to see the wildflowers and trees, and the eternal life of our beloved woods would fade. These hard-working beetles tirelessly replenish and support the forest food chain so, next time you are enjoying the sweet scent of woodland wildflowers, spare a thought for the underground heroes, undertaking the most undesirable task in the woods.
by Matt Parkins
Thank you to Dr Hilary Erenler from the University of Northampton for the inspiration and background information for this blog
Find out more about the Nicrophorus beetles at the Buglife website