The raccoon allegedly threatens endangered species. Its impact on biodiversity is now being researched in Saxony.
New scientific object: the raccoon Photo: dpa
In June 2012, pedestrians at the Federal Administrative Court are presented with a furry sight. In broad daylight, a raccoon climbs up the facade at the courthouse and basks in the sun. The otherwise rather crepuscular and nocturnal animals thus moved into the public consciousness. The species has been spreading in the city and surrounding areas since the 1990s. In view of the large number of animals in the Leipzig area, experts are increasingly asking themselves what influence they have on biodiversity and how the small bears should be dealt with.
For some time now, Andreas Sickert, Head of Department in the City of Leipzig’s Urban Forestry Division, has been receiving repeated reports from ornithologists, hunters and conservationists. The reason for this is the raccoon, which endangers rare animal species in the Leipzig floodplain forest, such as amphibians and nest breeders. For Sickert, "the potential threat is indisputable due to its food spectrum and skills."
The Federal Agency for Nature Conservation (BfN) classifies the animal as invasive, meaning potentially harmful to biodiversity. The EU Commission also placed the small bear on the "List of invasive alien species of Union-wide importance" in 2016.
The raccoon is not only an excellent climber, but also travels on land and water. As an omnivore, it helps itself to fruits, insects, worms, but also amphibians and birds. Because of its skills, the predatory mammal occupies an ecological niche; it has hardly any natural enemies. Especially in spring, when the raccoon has a high protein requirement and fruit trees do not yet bear fruit, amphibians offer a potential food source.
Sickert does not have a "secret recipe" for dealing with the animals in the long term. However, he does not consider the raccoon to be a widespread plague so far. For the past four years, the population has not been increasing, but rather fluctuating.
As part of the taz’s "Future Workshop," a separate page for Leipzig appears every Friday instead of the Neuland page, the taz.leipzig: planned, produced and written by young local journalists.
Rene Sievert, biologist and chairman of the Nature and Biodiversity Conservation Union Leipzig (Nabu), also observes the ecological impact of raccoons on other animal species. The situation is difficult for the tawny owl, for example, which was voted "Bird of the Year 2017" by Nabu. As an owl species, it lives primarily in tree cavities. Sievert noted that raccoons occasionally occupy them and thus displace the tawny owl.
The small raccoon also helps itself to some nests of rare bird species such as the red kite and amphibian waters in the floodplain forest, such as the highly endangered great crested newt and the common toad. However, Sievert does not know how great the influence of the raccoon on species diversity really is. There are other predatory mammals such as martens and domestic cats that also roam the forest. "And the biggest negative impact is from humans with increasing habitat fragmentation and intensive agriculture." In 2016 alone, he said, more than 60 hectares of green space were lost in the growth city of Leipzig because of the influx.
10,000 raccoons killed in Saxony
The German Hunting Association (DJV), on the other hand, is convinced of the negative impact of raccoons on biodiversity. It has therefore proclaimed 2017 the "Year of the Raccoon." In April, the advocacy group called for widespread hunting, especially in pacified districts, such as settlements and nature reserves. Currently, however, the Saxon hunting law prohibits hunting in the Leipzig settlement area. Outside of pacified areas, the raccoon has long been hunted. Last year, almost 10,000 raccoons were killed across Saxony; in the Leipzig area, more than 2,300 were killed in the 2015/16 hunting year.
Peter Winter is a member of the Leipzig Hunting Association, but he finds the DJV’s demands unrealistic: "It is not possible to hunt raccoons across the board in order to reduce their numbers; there are simply too many animals for that. They’re also difficult to hunt." Winter has worked in the southwest hunting district of the Leipzig hunting cooperative for 15 years. Because the bears are nocturnal, Winter can only hunt them by live trap, which is required by law in Saxony. In addition, female raccoons react to hunting pressure with increased fertility. One bear killed is soon followed by another. Winter would like to see closer cooperation with scientists in order to use collected data to take targeted hunting measures in smaller areas. "Because just hunting across the board is pure actionism and doesn’t achieve anything at all."
This is also the opinion of the Saxon State Ministry for the Environment and Agriculture (SMUL). Therefore, a joint project with conservationists and hunters is to start next year if possible. "The thesis is that the raccoon has a detrimental effect on native biodiversity. Now we need basic scientific data to get to the bottom of the complex causes," says Bert Dankert, species conservation officer at the ministry. Within three years, raccoon, mink and raccoon dog are to be hunted specifically in a "project area of particular value in terms of species conservation." "Then we look at how the population of breeding birds has changed before and after hunting," Dankert says. The tested methods could then be transferred to other areas in Saxony, such as the Leipzig floodplain forest. With its joint project, Saxony is playing a pioneering role nationwide.
Against general suspicion
Marten Winter therefore sees the Environment Ministry’s joint project as a step in the right direction. He is head of the Synthesis Center at the German Center for Integrative Biodiversity Research (iDiv): "We are still pretty much poking around in the dark in Germany when it comes to the effects of invasive predators. After all, how do you even determine that one species is responsible for the decline of another?" A few observations and the rising raccoon population wouldn’t be enough for that: "We first need statistically provable data to be able to assess what impact it really has."
In her doctoral thesis, Berit Michler found out that the raccoon at least has no negative impact on biodiversity in the Muritz National Park. Numerous rare animal species live in the nature reserve.
The biologist submitted her dissertation on the ecological impact of the raccoon to the Technical University of Dresden in early April. Together with other scientists, she conducted research on the small bear over a period of eleven years in the Muritz National Park. The current catalog of measures of the Ministry of the Environment is based on the research group, Michler welcomes the measures in Saxony.
For her doctoral thesis, the biologist analyzed more than a thousand raccoon fecal samples, examined the food components and correlated them with the food supply: "The scientific data from our food analyses show that the raccoon is a generalist and eats what it gets. This includes rare species such as amphibians, but there are no shortages."
Michler’s work is the first scientific evidence in Europe that raccoons have no negative impact on biodiversity. "Until now, people have largely speculated about the negative impact of raccoons and placed them under general suspicion. I hope that further long-term studies will help to return to a factual, constructive debate."