WHY did the hedgehog cross the road? Well, it turns out he didn鈥檛. In fact, it appears that the much-loved spiny creatures, whose tragic misadventures have made them the butt of such cruel jokes, do everything possible to stay off the asphalt.
鈥淲e were surprised they showed such strong avoidance of all but the very smallest roads,鈥� says Patrick Doncaster, a biologist at the University of Southampton who radio-tracked eight urban hedgehogs to see how roads affected their nocturnal foraging.
But hedgehogs haven鈥檛 suddenly acquired a new-found traffic awareness. The answer is simpler. Roads form an obvious physical barrier because the hard surface isn鈥檛 to the animals鈥� liking, plus there aren鈥檛 many tasty worms crawling around on the tarmac. 鈥淭hey鈥檙e not responding to the traffic, but to the road surface itself,鈥� says Doncaster. 鈥淚 don鈥檛 think they are fearful of cars as such.鈥�
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In Functional Ecology (vol 16, p 504), Doncaster and his colleague Carlo Rondinini point out that up to 350,000 hedgehogs die each year in the Netherlands, as well as a similar number in Belgium. Across Europe, the death toll averages 1 animal per year for every 1 to 2 kilometres of road. But Doncaster reckons this accounts for only a few per cent of the population.
Ironically, says Doncaster, hedgehogs are 鈥渙rders of magnitude鈥� more abundant in urban rather than rural areas, thanks to more food and fewer predators. For example, worms are easier to find on the short grass of playing fields and garden lawns, and badgers are less of a threat in towns than in the countryside.
The researchers have also established, using an unpublished analysis of hedgehog DNA, that males are more likely than females to brave the traffic. 鈥淚t鈥檚 quite likely the males are greater risk-takers,鈥� says Doncaster.