What Does The Wolf Eat? Mendel University Researchers Study The Diet of Wolves
As an alternative narrative to the story of Little Red Riding Hood, Mendel University researchers are studying the diet of wolves. In the latest part of our series about research on environmental issues at MENDELU, Brno Daily’s Coline Béguet accompanied the researchers from the forest to their laboratory, first following Miroslav Kutal, a specialist in large predators, during his field work monitoring the presence of wolves in a Czech natural reservation. Photo credit: Coline Béguet
Brno, June 4 (BD) – What are large predators? The term is partially arbitrary, in the sense that it is not a taxonomic category defined by strict criteria of physical and genetic characteristics, but is defined by their place in the food chain: they can eat most large herbivores and are not eaten by any other animal. In Central Europe, the term large predator therefore includes four species: the wolf, the brown bear, the lynx and the golden jackal. The fox is not included because it is only able to attack modest prey such as rodents.
Like other large predators, wolves were exterminated in the Czech Republic in the 19th century, for what were then considered to be security reasons. The first wolf reappeared in the country in 2014 and today there are about 25. They are now a protected species, due to their scarcity and key role in ecosystems. However, this status does not please everyone, especially rural populations and farmers who see them as a threat.
The main crux of the conflict is wolf attacks on herds of cattle. Wolves come to help themselves and, disconcerted by the abundance of easy prey concentrated in the same place and stressed by the presence of humans, they often kill many more animals than they eat. This situation is financially problematic, but also extremely stressful for breeders. However, Miroslav Kutal, an expert in carnivore conservation and the MENDELU Department of Forest Ecology, says there are solutions to cohabitation. Trials are being carried out in collaboration between breeders and nature protection associations to find ways to protect herds from attacks without culling wolves. Different methods can be used, such as electric fences or large herding dogs. These tests have so far been quite successful, but many sceptical breeders refuse to participate in the program.
In another attempt to find solutions to the difficulties of cohabitation between the agricultural world and wildlife, Kutal and his team are carrying out a project to study the eating habits of Czech wolves. If these are better understood, it will be easier to find solutions and protect both wolves and livestock. This is the main reason for today’s field expedition: to collect wolf droppings in order to bring them back to the university’s laboratory in Brno and analyse them.
This requires several hours of walking, departing from Ruprechtice in the very north of the country, where there is a nature reserve. I find Kutal at the train station, after I arrive 40 minutes late, because the train did not stop and continued into Poland. Maybe no one ever gets off at that stop and the driver decided to skip it, or maybe it was necessary to jump while it was moving, like in the classic Czech movie “Slunce, seno, jahody”.
We drive another ten minutes in the dawn mist, then park where the road ends. The long walk begins and we find ourselves in a forest that looks like a children’s fairytale, where the majestic fir trees are closer and closer and let less and less light through as we go on. The birds are silent as we pass and the only sound we hear is that of the branches cracking under our feet. Yet, to a trained eye, it is obvious that this forest is not empty. Many paths drawn by the daily passage of animals zig-zag through the bushes. Even on the wet earth of the human path, one can also notice numerous animal tracks. These are mostly from ungulates, wild boars or deer, but sometimes Kutal stops to observe what could be wolf tracks. They are often difficult to distinguish from those of large dogs, however the latter leave more round and wide prints while those of wolves’ paws have a more elongated shape, with tighter toes.
Wolves are creatures of habit, and often follow the same paths to get from one end of their territories to the other. They are also clever and know how to use the infrastructure; rather than the effort of sneaking between bushes, they often prefer to use pre-existing roads, in particular those made by humans, wide and well-defined. Wolves live in families of variable size, and in established territories, with the exception of the younger ones who have just left their parents and are looking for a life partner and an available territory.
When we find wolf droppings, Kutal begins by photographing them with a measure to record the exact size, then immediately uses his phone to enter the photograph into the national database for monitoring large predators, including adding the exact GPS coordinates. He then takes a sample for the laboratory. This step varies according to the state of preservation of the excrement. For the study of diet it is enough that they are still well formed and that the decomposition is not too advanced. But Kutal also sometimes tries to take samples that will be used for DNA analysis and, for this, the excrement must be still fresh. For these samples, he takes only a very small piece, using a wooden stick, which he places in a tube with preservative liquid. Each sample is carefully packaged, numbered, and entered into the database.
How can we distinguish wolf droppings from dog droppings? First of all, they have a very characteristic smell. According to Kutal, dog droppings smell terrible, while wolf droppings do not. “Well, it’s not a pleasant smell either,” he clarifies, prone in the fir thorns, “but it smells of, um… forest.” And above all, wolf droppings are… hairy! Indeed, wolves waste nothing of their prey, and consume everything including bones and skin. That’s why their excrement looks like strange balls of hair after it has dried. It is sometimes even possible to find preserved elements in their excrement such as the whole hooves of young deer.
I ask Kutal if he has ever seen wolves during these research expeditions. “Yes, it has happened, but that’s not the point. We don’t want to disturb them, but study them without being intrusive.” For this in particular, researchers install automatic cameras in the wolves’ territory that are triggered when they detect movement. These make it possible to map the areas of activity of the animals, as well as their population. Kutal places them in strategic places, where paw prints or excrement suggest that these are paths regularly taken by wolves.
Many volunteers assist with the national monitoring programme of large predators. This is coordinated by the Hnutí DUHA association, in which several MENDELU scientists, including Kutal, are involved. Teams of volunteers roam the forests, looking for indications of the presence of large predators and, like Kutal, enter their findings in the national database. This information collected by the volunteers makes it possible to estimate the population of these animals, as well as tracking their movements through the country and better understanding their habits.
But is it dangerous to walk where there are wolves? Kutal says attacks on humans by wolves are truly exceptional and have not happened in the country for centuries. Above all, he explains, the large predators of our forests are much less dangerous than much more common things we encounter every day, such as cars, mosquitoes or stray dogs. But “people are afraid of what they don’t know,” Kutal laments. Wolves have always nourished the human imagination, giving rise sometimes to fear, sometimes to adoration, but never to indifference. For many, wolves are “symbols of wildness,” says Kutal, for better and for worse.
At the end of a long day of walking, we finally start returning to civilisation, laden with more than 20 samples of droppings, a very good haul according to Kutal, who rarely finds so many. These will be brought to the Mendel University laboratory, then stored in fridges before being analysed. Look out for the next part of the series, in which we will explore what our wolves actually eat, and why it is useful both for the forest and, in some cases, even for agriculture!