Wild boar not bad for biodiversity in Britain’s woods

Britain's bluebells and beetles are standing up to wild boar September 2011. Britain's beloved bluebell woods appear to be standing up well to the wild boar that escaped from farms and have been breeding here for the past 20 years, new research has found.

Extinct in 13th century
Native populations of wild boar became extinct in the UK during the 13th century but during the last two decades several small, isolated, breeding populations have established from animals which escaped following the start of commercial farming. Often regarded as a pest elsewhere, its effects in Britain have been little studied and because its current distribution is so restricted, it is not yet clear whether its presence should be welcomed, tolerated or prevented.

Dr Ralph Harmer of Forest Research studied the impact of wild boar on UK woodland plants and invertebrates. Working in woods near Rye, East Sussex, which are home to the UK's oldest wild boar population, he identified 12 sites with varying amounts of rooting. By surveying the woodland at the height of the bluebell flowering season and using a specially-designed "armoured" pitfall trap capable of withstanding the wild boar to collect invertebrates at each site, he was able to assess the impact of rooting on the woodland's beetles and bluebells.

According to Dr Harmer: "The most obvious sign of boar in these woodlands is soil disturbance caused by rooting. During spring many of these woods are carpeted in blue and white by luxuriant displays of bluebells and wood anemone and the potential effect of boar on bluebells has raised concerns."

33 species of beetle
His findings should, however, help allay these fears. Some 67,000 invertebrates - including 33 species of ground beetle - were identified from the pitfall traps, which were emptied every two weeks between April and August. Although the mix of beetle species varied between sites, rooting had no adverse effect on either the number of species found or the total number of beetles living in each wood.

There were large differences in the abundance of bluebells and the amount of rooting between woods, and overall there was generally more rooting activity where there were more bluebells. However, analyses found that boar do not strongly target rooting activity at patches of bluebells.

"There was no apparent adverse effect of rooting on either the ground beetle community or the other groups of ground dwelling invertebrates. Overall results suggest that if boar populations and rooting activity remain similar to those of the last 20 years then ground dwelling invertebrates may be largely unaffected and whilst there may be a reduction in the amount of flowering, bluebells are not unduly threatened in the short-term," he says.

http://www.wildlifeextra.com/go/news/britain-boar011.html