What had happened? When Stefan Böckling, founder of the initiative Tiernotruf e.V., was called to Bonn, the six nutrias had already spent almost a week in the sewers, without food and in complete darkness. Böckling, together with volunteers, was able to get the animals out of the sewer system in an eight-hour operation. During the rehabilitation of the Rheinauensee, the nutrias had sought refuge in a pipe that protruded into the lake, which had been pumped dry at the time. Every evening, a group of volunteers coaxed the animals out of the tube to feed them. When the renovation work was completed and the Rheinauensee filled up again, the animals had disappeared. The reason: the tube they were sitting in had been sealed with a so-called balloon to prevent the water from draining out of the lake.

As Böckling explains, the volunteers had previously offered the city of Bonn their help to lure the animals out of the tube. However, the city is said not to have accepted. According to a spokesperson, employees were sent to "carefully" search the branched pipe system for nutria, and the pipe was only closed after no animals were discovered there.

But Böckling suspects that the animals were able to hide well in the dark, narrow shafts, some of which are covered with centimetres of mud. The nutria family was trapped.

There was no escape on the other side of the pipe either. There is a drain leading to the Rhine, but its current is probably too strong for the animals. Böckling explains: "The nutrias would have had to jump in there in the pitch dark. But nutrias are not stupid. They don't jump into an unknown current without knowing where they will arrive.“

The city of Bonn sees it differently: "The canal system leads into the Rhine. At the exit there is a grid with eleven-centimetre gaps between the bars. There is also a slightly larger gap under the grating because some concrete has broken away here," the city spokeswoman describes. Since nutrias, like all rodents, can make themselves very flat, the city had assumed that nutrias could use these openings as an exit. "In the other direction, however, i.e. as an entrance from the Rhine into the canal system, the opening does not work because there is a step in the canal slightly in front of the grating."

The city has another explanation how the animals must have got into the pipe under the Rheinaue: "The set bubble was unfortunately damaged and removed three times by unknown persons. During the last removal, the water level was already so high that an enormous suction must have been created. If there had been nutrias in the canal system at that time, they would have been washed into the Rhine or into the area between the step and the grating. The city therefore assumes that the animals only entered the canal afterwards," the spokeswoman explains. She does not explain exactly how this was possible.

The fact that it was noticed at all that six nutrias had been caged is thanks to the volunteers who regularly fed the animals during the renovation work - despite the express ban on feeding, which the City of Bonn again points out in the context of our enquiry. As can be seen in the Facebook video, they have not only named all the nutrias, the animals are also very trusting towards them. "Without the knowledge of these people, I would not have been able to do the operation," explains Böckling, who founded the animal emergency service as a private one-man initiative and is now called to animal rescues all over Germany.

How angry he is that his intervention was necessary at all can be seen in his telephone conversation with our editorial team: Instead of crawling through the sewers for eight hours, he thinks the city of Bonn should have taken up the offer of the volunteers. "Why am I sending people through the sewer when animals are lured out of the tube and fed every evening? The city could have closed the access right behind the nutrias. That would have been a two-minute operation.“

The city of Bonn wants to make rescue operations like this unnecessary in the future. "In the next stages of rehabilitation, the city would like to work more closely with citizens who are committed to the nutria in the Rheinaue," says the spokesperson. Contact has already been made with two volunteers. "An appointment has been made with them for the insertion of the bladder in the next lake area to ensure together that there are no nutrias in the canal system. When the water is drained in the next lake areas, the city plans to close the drain pipes so that the nutrias can't get into the canal in the first place.“

Stefan Böckling is nevertheless considering pressing charges. "Even if nutrias are not wanted as an invasive species in this country, the same animal protection law applies to them as to all other vertebrates," he says. "And this prohibits inflicting prolonged, avoidable pain and suffering on them."

Original text: Sandra Liermann

Translation: Mareike Graepel