Science & Technology, UK (Commonwealth Union) – A team from the University of Oxford has introduced a novel examination method to gauge the potential harm posed by robotic lawnmowers to hedgehogs. Their objective is to establish a certification system that empowers consumers to select lawnmowers deemed ‘hedgehog-friendly,’ with the aim of safeguarding these beloved creatures.
As the popularity of robotic lawnmowers rises, concerns mount over the possible threat they pose to European hedgehogs, particularly during their nocturnal activity periods. This species is already facing a significant decline due to factors such as habitat loss, road accidents, intensive agriculture, and injuries caused by dog bites and garden strimmers. In recent times, numerous hedgehog rehabilitation centers have reported a notable surge in hedgehog injuries attributed to encounters with robotic lawnmowers.
Lead researcher Dr. Sophie Lund Rasmussen, affectionately known as ‘Dr. Hedgehog’ at the University of Oxford, emphasized the pressing need to identify and phase out robotic lawnmower models that endanger hedgehogs. The team has devised a standardized safety test, which, when adopted, is expected to contribute significantly to hedgehog conservation. This test will enable robotic lawnmower manufacturers to ensure that their models adhere to hedgehog-friendly standards before entering the market.
Dr. Rasmussen’s inspiration for the test stemmed from conducting collision experiments between robotic lawnmowers and deceased hedgehogs obtained from hedgehog rehabilitation centers. These hedgehogs were deemed beyond recovery due to injuries or illnesses.
According to Dr. Rasmussen, in his findings, he observed that all the robotic lawn mowers he assessed required physical contact with a hedgehog to detect its presence. Shockingly, some of these mowers failed to detect a deceased hedgehog altogether. The robotic mowers exhibited varying levels of impact, ranging from a gentle nudge and change of direction in milder instances to running straight over the hedgehog with active blades in the worst-case scenario, resulting in significant damage to the hedgehog carcass.
In response to these concerning outcomes, a new safety test has been introduced, employing specially designed hedgehog ‘crash test dummies.’ The objective is to determine whether a robotic lawnmower can effectively avoid a real hedgehog and, if not, to assess the extent of damage caused during a collision.
To ensure the test’s realism, researchers collaborated with a hedgehog rehabilitation center in Denmark. The center provided insights into the reactions of live hedgehogs, prepared for release into the wild after receiving care, to robotic lawnmowers. The researchers conducted tests on fifty hedgehogs in a controlled environment using a bladeless robotic lawnmower, positioned 50 cm away from the hedgehog.
The results revealed three distinct responses from the hedgehogs: fleeing from the mower, standing rigidly in front of it while partially curled up, or curiously sniffing the lawnmower. Generally, younger hedgehogs exhibited more bold behavior compared to their adult counterparts.
Dr Rasmussen says “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.”
Utilizing their discoveries, the researchers have pinpointed the optimal positions for placing a crash test dummy to replicate the primary responses of a live hedgehog during a lawnmower safety examination. Crafted from a pliable rubbery plastic that closely emulates the body composition of a genuine hedgehog, the dummy was designed based on initial collision tests.
