Scientists widely recognise the importance of dead wood for biodiversity. A wide array of birds, mammals, amphibians and many insects make use of dead wood in their life cycle. One could perhaps even say that dead wood is more alive than a living tree. But not only dead wood is important for biodiversity. More and more, we begin to understand the importance of dead animals in nature. Pilot studies examine the nutrient cycle, as carcasses provide food for other animals. And some of the results so far have been surprising and astonishing!
Please also read: Good forest means dead wood
Rotting reindeer in Lapland
It was August 2016 when a lighting strike had killed over 300 reindeer on a plateau in Norway. The park management responsible for the plateau decided not to remove the carcasses. Instead, the park would leave them for nature to take its course. It provided a great opportunity for scientists to study the processes of decomposition and its effect on the local ecosystem.
In most parts in Europe, the law forbids to leave carcasses out in the open. This is in order to prevent spread of diseases, nuisance of smells, and an unpleasant visual experience for people. However, as the plateau was remotely located, at least a 3-hour hike from the nearest town, it was possible to leave it as it was. Scientists installed camera traps and other measuring devices to observe and record the natural processes. At first, the scientists felt mostly solemn to watch so many dead animals. But as natural events started to unravel, scientists learned about new processes, overcoming the feeling. After all, “… it’s silly to deny death as part of life”, says one of the researchers.
Circle of life
In the first year, mostly scavengers visited the study site. Ravens, crows and eagles were mostly picking on the carrion in 2017, but disappeared in the following year. Instead, rodents arrived such as voles and lemmings. Very likely, these rodents were too afraid to share the meal with the large birds, wanting to avoid to turn into a meal themselves. Also other bird species appeared on site, mostly feeding on the insects that were attracted to the carrion. As the scientists say, we need to further study the benefit of carcasses for these non-scavenging birds to support conservation efforts.
Not only animals benefitted from the remains of the reindeer, so did the local plats. As scavengers were visiting the site, they dropped viable plant seeds with their faeces. Over the following years, the plant composition thereby changed close to the carcasses.
As we are facing the climate emergency, the frequency of weather extremes increases, so does the occurrence of mass mortality events. Last year’s Australian bushfires have costed the lives of many hundreds of millions of animals, for example. The current fires in the Amazon, like last year, are also taking lives of many animals, including amphibians, invertebrates and insects. Also in Kazakhstan, 200 000 saiga antelopes died in 2015 because of a pathogen that became harmful due to the warm weather. Meanwhile, that year also costed lives of over 1 million seabirds due to warm temperatures around the ocean of North America. Understanding the role of scavengers better, will also mean that we improve our understanding of the ecosystems. The interactions and connections in food webs are important to maintain a stable ecosystem that can withstand a certain fluctuation in environmental conditions.
Especially important are those scavengers that may perform long-distance movements and distribute nutrients over large spatial scales, such as vultures and large mammalian predators.
Death brings life
The Dutch organisation ARK initiated a project ‘Dood doet Leven’ where they are working together with several organisations to restore a place for dead animals in nature. By doing so, they create a place for scavengers to return. The project has been successful already, as you can see in one of their videos below. It shows the diversity of animals benefiting from a carcass. In a matter of merely weeks, an entire red deer can be consumed and recycled to the bone. It is a good example that letting natural process take their course are benefitting the ecosystem, to ‘let nature be nature‘.