Two-dimensional animals that won’t move
In New Zealand we are supposed to have about 100 x 106 possums (Trichosaurus vulpecula). But if one asks some of the foreign visitors to New Zealand, if they had seen any possums in the wild, they will answer “Only some on the roads, run over by cars”. Such comments reminded me of my stays in Australia, where the only spiny anteater (Tachyglossus aculeatus) outside a zoo, which I had ever encountered, was a flat, dried up carcass on a road leading to Melbourne. And when one day in northern Finland on the carpark in front of her kindergarten my little daughter pointed to a dry and flat, pancake-like thing (which had once been a toad), I thought by myself, I ought to write a book about animals flattened by cars and lorries. Yet, as I learned when embarking on the project, such an identification guide to animals killed on roads, streets, and highways already existed.
Written by Roger M. Knutson of Luther College in Iowa, the book is called “Flattened Fauna” and represents a stark reminder that more and more people learn about wildlife only from dead and flat animals found on (or along) roads and highways. When an animal is transformed from a three to a two-dimensional condition through the flattening action of a car or lorry, then identification of such animals is not straightforward, for the latter have taken on a look very different from when they were alive. Some are more easily recognizable than others: snakes for example. Others pose greater problems.
Animals with short legs are usually squashed in a dorso-ventral direction and end up spread-eagled and flat with their four legs projecting outward. Slender and thin animals become fat and seemingly ‘ironed out’ when run over and animals with longer legs like rabbits commonly lie on their sides. In birds quite often one of the wings is spread and feathers are dislodged. Some of the ‘road-fauna’ are seasonally more abundant like snakes and lizards, which you would not encounter in winter. Toads and other amphibians are most frequent in spring, when they go on their annual migrations to ponds and other water bodies to breed.
But why do so many animals (and Knutson mentions over a hundred species of vertebrates) come to the roads at all when they are such dangerous places? Well, snakes and other reptiles are attracted to roads, because these animals warm their bodies on the road surface. Birds flock to roads because they feed on carcasses of road victims or on items like potato chips, bread crumbs, etc. carelessly thrown out of the window by the occupants of cars. Some animals, needing to cross a road, because their habitats shrunk or were destroyed, are simply too slow to make it to the other side. One gets the impression that roads and highways turn our countrysides into a patchwork of ever-decreasing areas for wildlife, delineated by deadly borders. Clearly, the dangers of the road represent an evolutionary pressure, which animal species either respond or succumb to.
The European hedgehog, for example, used to have the habit of rolling itself into a prickly ball when threatened. But now individuals following this strategy end up flat and dead and only hedgehogs with a gene for running away when danger approaches in the form of a car will survive and reproduce. So, while it’s sad to see so many flat and dead animals on our roads, there is hope that some will adapt to the dangers and, moreover, as long as we do see flat and dead animals on our roads at all, we know they haven’t yet altogether become extinct. And that’s the only thing positive I can say about flat animal road victims: they show us they are still around.
© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2020.
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