Facts instead of hunters' tales: raccoons are not a threat

The raccoon belongs to the American prey animal family of procyonids. It has a highly developed sense of touch and thoroughly feels its food with its front paws. This is what led to its name. The raccoon is a good swimmer and climber. In Europe it was bred for its fur. «Individual animals escaped or were deliberately released, particularly in Germany and northern France, where local free-ranging populations were able to develop», notes the reporting office Kora. As early as the mid-1970s, the first raccoons were spotted in Switzerland.

Editorial team Wild beim Wild — 6 June 2019

More and more raccoons are crossing into Switzerland from Germany. In 2018, a long-term study on the procyonids was concluded in the Müritz National Park.

For a full six years, Dr. Berit Michler and Dr. Frank-Uwe Michler led a research project in part of the Müritz National Park . The subjects of their work: raccoons. Last year they concluded what was, until then, the most extensive and longest field study ever conducted on the procyonids. Berit Michler recently presented some of their findings at Hohenzieritz Castle, as Martina Schwenk reported in the Nordkurier.

One major question that was on the table: is the raccoon dangerous to native and, above all, protected animal species?

No, is the conclusion of the research.

Over the years, 145 animals were captured and examined for the project, with 69 subsequently monitored using radio collars. And a large number of faecal samples were collected. “We analyzed the samples in Berlin to find out what the raccoons' diet consists of”, said Michler. On an annual average, the procyonids in the national park feed on soft-bodied invertebrates such as earthworms and snails for more than 50 percent of their diet. Plants account for 32 percent. Only then come vertebrates. “The raccoon is an opportunist that takes what it can get. There is no specialisation in any particular food. Therefore, no negative impact from raccoons in the Müritz National Park is to be expected in the future either.“

Do raccoons raid nests?

Some participants in the discussion suspected that the hunting success of the small bears was behind the declining numbers of birds, especially ducks. More precisely, that the cute masked animals would be raiding nests. And whether it was even possible to detect eggs in their diet. It is, Michler confirmed. "At the Neustrelitz Zoo, we fed eggs to raccoons specifically to test this. Every time, we found eggshells in the droppings afterwards."

In general, the small bears are doing very well in the national park. The researchers had selected an area where the animals have virtually ideal living conditions. This can also be read from their territorial behavior, according to Michler. As the data from the radio collars showed, the territories in the national park were relatively small. "This means the raccoons find enough food within a relatively small area."

In samples from the wild, however, the researchers found no eggshells. As a control sample from a cultivated landscape, droppings were also collected in the Feldberger Seenlandschaft. There, the animals fed more heavily on plants.

Hunters' tales in Switzerland

If a raccoon falls into a trap in Switzerland, its fate is sealed. «Then we shoot it. We have to», explains hunting warden Amidé Franzen from Kaiseraugst. Because raccoons belong to the neozoa in Switzerland — non-native species. They may be shot all year round. «Raccoons are omnivores and predators. They raid bird nests and eat the eggs. We also have to make sure they don’t get into houses and nest there. You almost can’t get rid of them once they do. That’s a problem in Germany», explains Franzen.

According to Erwin Osterwalder, specialist for hunting and fishing at the Canton of Aargau, there are a few sightings of raccoons every year. «It is here, but not yet widespread.» There have also been some shootings in Aargau. «The raccoon is a strong competitor for native fauna, which is why it is also unwanted here under federal hunting legislation. It is a North American species that has made its way into Switzerland via Germany.»

The natural enemies of young raccoons are lynx, eagle, eagle owl, and fox. Hunting and road accidents are the two most common causes of death.

Males roam, females stay in their territory

Im Herbst wanderten allerdings viele der mit Sendern versehenen Tiere im Müritzer Nationalpark eine grössere Strecke. Dieser Weg hat einen kulinarischen Grund: die reifen Früchte der spätblühenden Traubenkirsche. „Waschbären legen ihren Kot auf erhöhten Stellen ab, vorwiegend auf umgefallenen Baumstämmen. Diese Latrinen dienen aber auch dem Informationsaustausch“, erklärte Michler. Auf diese Weise erfahren die Kleinbären über den Kot von Artgenossen von den reifen Leckerbissen und ziehen los.

Das kann man verhindern, und zwar mit speziellen Manschetten um den Baumstamm.

Der Waschbär

Es sind vor allem die Männchen, die wandern. Weibchen dagegen haben feste Reviergrenzen. „Blutsverwandte Fähen schliessen sich in Gruppen zusammen, sogenannte Mutterfamilien. Diese Linien haben feste Grenzen zu anderen Gruppen“, erklärte Michler. Rüden dagegen verlegen ihre Gebiete und wandern zur Paarung durch die Reviere der Fähen. Ganz wichtig dabei: „Rüden paaren sich nie mit ihren eigenen Töchtern.“ Damit vermeiden sie gezielt Inzest.

Wichtig war auch, wer bei den Waschbären eigentlich für den Nachwuchs sorgt. Vor allem ältere, erfahrene Fähen ziehen demnach Nachkommen gross. Jährlingsfähen, die gerade geschlechtsreif sind, bekommen entweder keine Jungen oder kriegen sie oft nicht durch. Unter anderem fehlt ihnen die Erfahrung. Allerdings, so berichtet Michler, gibt es Ausnahmesituationen. „Wenn mehrere Tiere aus einem Revier sterben, beteiligen sich die Jährlingsfähen in der nächsten Paarungssaison verstärkt. Zudem zeigen Beobachtungen, dass die Tiere dann mehr Jungen gebären als sonst.“

Staupeausbruch im Nationalpark registriert

Das konnten die Forscher auch im Nationalpark beobachten. In einem Jahr, berichtete Michler, trat die Canine Staupe auf. An der Krankheit starben etliche Waschbären. Im Jahr darauf kamen ungewöhnlich viele Jungen zur Welt, sodass die Verluste schnell ausgeglichen wurden. Der Staupeausbruch beschränkte sich zudem auf ein einziges Revier. „Dadurch, dass die Reviere der Mutterlinien feste Grenzen haben, konnte sich die Staupe nicht ausbreiten“, erklärte Michler. Ob die Kleinbären Überträger von Krankheiten seien, fragte ein Jäger nach. Oder ob es Fälle von Räude gebe, fragte ein anderer. Nein, sagte die Forscherin. Neben Untersuchungen lebender Waschbären hatten die Forscher etliche Totfunde obduziert. „Apart from distemper, no transmissible diseases were detected in the local population."

The otherwise matter-of-fact discussion briefly grew heated. An audience member asked how the number of animals could be reduced and how they could be gotten rid of. "That's why we're here", the man said. "You've probably misunderstood the topic of the presentation", Michler replied calmly, advising caution against sweeping statements. "Where one species of predator lives, others live too. Blaming the raccoon alone for declining bird populations, for instance, would be premature." Especially since vertebrates — and birds in particular — are demonstrably eaten by raccoons only very rarely. Ultimately, the raccoon has already reached its peak population in the national park. It would continue to spread in Germany as well. "The raccoon is here to stay, but we can learn to live with it", said Michler.

Facts instead of hunters' tales

It has long been scientifically established that raccoon hunting stimulates reproduction while also destroying age structures and social structures.

The attempt to push back raccoon populations through hunting is now considered hopeless and has failed. Numerous scientific studies have shown that hunting predators has little or no influence on the breeding success of ground-nesting birds or on the population densities of small game. Hunting predators leads to no reduction — or at best only a short-term reduction — in population density, since losses are immediately offset by immigration and increased litter rates.

In many North American states, hunting is the most common cause of death for raccoons, claiming the lives of nearly half the population each year. Yet the population does not decline. Instead, hunting interventions cause a drastic shift in age distribution. The entire social structure is dramatically manipulated and thrown into complete disarray by recreational hunting.

Biologist R.J. Robel and his colleagues studied the effects of additional human-caused mortality as early as 1986 by comparing two areas in Kansas (USA). In one area, 52.5 percent of all raccoons died within a single year, most of them due to hunting or road traffic. In the other area, which had few roads and houses and where no hunting was practiced, only 26.5 percent of all animals died during the same period. The researchers found that in the undisturbed population, juvenile animals were in the minority at 28 percent. In the disturbed population, the opposite was true: juveniles made up a clear majority at 62 percent. Every older female and 38 percent of all yearling females were pregnant.In the undisturbed population, none of the yearling females became pregnant, and only 50 percent of the older females did.

Interestingly, no reduction in population size was observed in the hunted population — only the shift in age class structure described above. The raccoons were thus able to compensate for a high mortality rate with a high birth rate.

Despite the high mortality among juveniles and adults, the yearlings growing into the adult cohort represent the largest fraction. In some years, they account for as much as half of all animals of reproductive age. They therefore play a critically important key role in compensating for large losses. In stable populations with low mortality rates, young females take their time before becoming mothers, and it is not uncommon to find no pregnant animals among the yearlings. If, on the other hand, many animals die over the course of a year, young animals typically also participate in reproduction. In such cases, up to three-quarters of all yearling females and nearly all multi-year females become pregnant. In these situations, first-time mothers alone — by virtue of their sheer numbers — account for the lion's share of offspring production.

Based on these and other wide-ranging scientific studies, it becomes clear that hunting represents nothing more than the ultimate distortion of fauna, with drastically negative consequences. Hunting amplifies the very problems it claims to solve. This is true not only when it comes to hunting raccoons, but also, for example, with foxes. Negative effects and excesses of hunting can be observed worldwide. Recreational hunting is a violent, destructive intervention in sensitive structural and ecological systems, with negative chain reactions — not only for the hunted species itself.

On a list published by the EU of the “100 worst invasive animal species on the continent”, the raccoon does not appear at all, unlike the cat or the trout.

Raccoons do eat birds, but these make up only about 3.1 percent of their total diet. Amphibians account for 5.7 percent, reptiles only 0.11 percent — which shows that the claim that raccoons threaten protected amphibians and reptiles is only partially correct. Using their highly sensitive front paws, they occupy an ecological niche in their foraging that was previously unfilled. They therefore do not compete for food with other native species, as stated, for example, in an information brochure published by the Berlin Senate.

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