German mayors have called for a nationwide ban on night-time use of robot lawnmowers to protect hedgehogs and other small nocturnal animals from being killed or maimed in the dark.

Recent studies have highlighted the threat lawnmower blades pose to wildlife active between dusk and dawn, prompting growing calls for regulation. Hedgehogs also tend to curl into a ball when threatened rather than running away, making them harder for a robot mower’s sensors to detect.

“Many animals are active in gardens, particularly in the evening hours. They also depend on these green spaces in the immediate vicinity of residential areas,” said Claudia Kalisch, the vice-president of the German federation of cities.

Kalisch, who is the mayor of Lüneburg in northern Germany for the Green party, said cities had become substitute habitats for many of the mammals as property development and intensive agriculture encroach on their habitats.

“That is why a nationwide ban on night-time operation [of the lawnmowers] is a logical protective measure,” she told the Funke newspaper group, after petitions making a similar appeal drew tens of thousands of signatures earlier this year.

Kalisch said companies making automated garden equipment had a responsibility to do more to protect wildlife.

“We are also calling on manufacturers to find solutions to ensure that small animals are no longer endangered by robotic lawnmowers,” she said on behalf of the cities’ federation.

“This is a key step towards protecting animals and enriching the quality of life in the city through biodiversity.”

Hedgehogs have appeared on the “near threatened” red list of the International Union for Conservation of Nature since 2024 after a drop in numbers of at least 30% over the previous decade.

Beyond lawnmowers, motorised leaf blowers and vacuums can also be harmful to hibernating hedgehogs, while up to one in three are run over by vehicles, a big factor in their drastic decline across Europe over recent decades.

Researchers at the University of Oxford, collaborating with colleagues in Denmark, published a study last month showing hedgehogs hear high-frequency ultrasound, raising hopes that they could be deterred from dangerous roads with sonic repellers.

Oxford experts have also used crash-test-dummy hedgehogs, created with the help of 3D printers, to work with industry in the hope of enabling a certification scheme that would allow consumers to choose “hedgehog-friendly” mowers.

Study co-author Anne Berger, of Germany’s Leibniz Institute for Zoo and Wildlife Research, said injuries from robot lawnmowers placed an “enormous burden” on animal care centres.

“Moreover, the majority of hedgehogs with cut injuries are found days or weeks after the accident happened and therefore have to endure considerable suffering, pain and harm,” she added.

Hedgehogs are subject to protection under German law, with trapping, injuring or killing of them subject to fines of up to €65,000 (£57,000).

Several German urban areas have already outlawed night-time use of robotic lawnmowers, including Cologne, Leipzig and Munich, but a recent attempt by the Greens to impose a statewide ban in Bavaria failed to pass.