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MAMMAL CONFERENCE
THE HEDGEHOG’S PLIGHT PAT MORRIS The hedgehog is one of our most popular and easily recognised mammals, normally considered to be ‘common and widespread’. However, in recent years people have commented increasingly often that they see fewer these days or that hedgehogs no longer come to their garden. These casual observations have become so frequent as to seriously question the status of this species. Anecdotal information is insufficient to make a strong case, but there is no accurate way of estimating population size or local abundance of species like this that live at a low population density and are not amenable to large-scale trapping or direct observation in sufficient numbers to ensure statistical validity of any assessments regarding population size. Instead we have to rely upon indices of relative numbers to support suggestions that there have been changes in abundance. The most obvious index is the number of hedgehogs seen dead on our roads. In the 1990s, I began a study in which volunteers recorded the numbers seen dead on various journeys, following strict instructions that ensured everyone was making observations in the same way. Nevertheless, I was castigated for being unscientific and doing nothing more than inventing a crude method of measuring traffic density! However, there was good evidence that numbers seen dead per 100 miles driven were not related to traffic density and moreover were consistent regionally from one year to the next. More recently, my colleague Paul Bright has confirmed (with rabbits) that numbers seen dead on the road are a direct reflection of numbers alive nearby. The ‘roadkill index’ is thus a satisfactory way of indicating relative abundance from year to year and place to place. Nowadays we can harness far more observers via the internet and make comparisons with 20 years ago. It seems that hedgehog numbers have reduced by about 30% in that time and continue to decline. Moreover, data from the Game Conservancy Trust show that numbers killed by gamekeepers have halved in 50 years, and it’s not because gamekeepers are getting lazy! Surveys by both the British Trust for Ornithology and by the Peoples Trust for Endangered Species show that numbers of hedgehogs seen in gardens have declined by about 5% each year in recent times. It all points to a significant cause for concern. It is likely that many factors have brought about this decline, notably the intensification of agriculture. A century ago, when horses were abundant, their grazing created excellent feeding areas for hedgehogs who could also nest in nearby hedgerows. Changing to arable crops and removing hedges to make harvesting more efficient has left the hedgehog with poor habitat across vast swathes of our countryside. The use of pesticides to improve crop yields removes many of the beetles, worms and other creatures that the hedgehog depends upon for its nightly nourishment; deep ploughing doesn’t help either. Flail mowers thrash the grass verges of our roads, exactly where many hedgehogs will lie up during warm summer days. Garden strimmers mangle many more, not to mention the 15,000 or so that are killed annually on our roads. In urban areas, modern fencing obstructs free movement, as do the many miles of concrete barriers down the middle of our Trans. Suffolk Nat. Soc. 51 (2015)