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Researchers develop hedgehog safety test for robotic lawn mowers

WildCRU Research Associate Dr Sophie Lund Rasmussen has led new work assessing how dangerous robotic lawnmowers are to hedgehogs. The authors hope this will lead to a certification scheme that will allow consumers to choose ‘hedgehog-friendly’ mowers.

European hedgehog populations (Erinaceus europaeus) are in decline – increasingly sharing habitat with humans and being exposed to a range of dangers including road traffic accidents, intensive agriculture, and injuries from dog bites and garden strimmers. In recent years, many hedgehog rehabilitation centres have reported a significant increase in the numbers of hedgehog injuries caused by robotic lawnmowers. These machines are becoming increasingly popular, however many are concerned that using them, especially at night when most hedgehogs are active, could pose a threat to European hedgehogs.

Dr Rasmussen, aka ‘Dr Hedgehog’ says, ‘There is an urgent need to identify and phase out models of robotic lawnmowers that pose a threat to hedgehogs. Our new standardised safety test will greatly aid hedgehog conservation, by enabling manufacturers of robotic lawnmowers to ensure their models are “hedgehog friendly” before they are put on the market.’

The safety test was developed through exploring both the reactions of live hedgehogs as well as crash test dummy hedgehogs. Overall, hedgehogs showed three distinct responses: running away from the mower; standing rigidly in front of it partially curled up; or sniffing the lawnmower inquisitively. Generally, younger hedgehogs were bolder than adults.

Dr Rasmussen said, ‘Each hedgehog was tested twice and, interestingly, they tended to act more shyly on their second encounter. This is hugely important, since it suggests that hedgehogs may learn from their first encounter with a robotic lawnmower. Potentially, if a hedgehog survives its first encounter with a robotic lawnmower, it is less likely to be injured in the future because this may cause it to avoid them. So, the more hedgehog friendly mowers out there, the more chance there is that the first mower a hedgehog meets is a hedgehog friendly one. If these hedgehogs meet a mower again later in their lives, they will then likely be more cautious.’

The team intend to make the crash test dummy design publicly available for 3D printing, so that robotic lawn mower companies can use it in the process of developing hedgehog friendly robotic lawnmowers. Ultimately, they hope that the hedgehog safety test using the dummies will become integrated into the official testing protocols approving the robotic lawnmowers for sale on the European market. This could enable a certification scheme that will allow consumers to choose ‘hedgehog-friendly’ models.

Fay Vass, from the British Hedgehog Preservation Society added: “We are pleased to have been involved in funding this important piece of research. The population decline of hedgehogs is alarming and unsustainable so it’s crucial to find out which potential dangers are actually causing problems, and which are not.”

Access the published scientific articles here:
https://www.mdpi.com/2076-2615/14/1/122
https://www.mdpi.com/2076-2615/14/1/2