Michael Walters' latest update:
There can be few more stirring sights than a magnificent stag red or fallow deer brushing his antlers from side to side and bellowing in the rutting season, or marvelling at the prowess of a roe deer easily clearing farm fences like an Olympic hurdler; just being privileged to watch these timid beasts quietly grazing is so inspiring in our largely sanitised countryside. But man (and it is invariably men who meddle with nature) has, by design or by accident, introduced four of our six species of deer to the UK - only the red and roe are thought to be native. So often these introductions of plants and animals have a sting in the tail, and there is now rising alarm about the damage being caused to lowland woods, particularly by muntjac deer, a Chinese species brought to Woburn Park a hundred years ago.
Muntjac, and to a lesser extent fallow, are browsers; that is to say they feed primarily on leaves of shrubs rather than grazing on grass like sheep and cattle. Both these species are now well-established in south east England - the above graph says it all, with a dramatic rise in the muntjac population since monitoring began in 1995 (the units on the y-axis are an index starting arbitrarily at 100 in 1995, and a straight trendline has been superimposed on the annual estimates). The problem is that browsing by large numbers of these animals can eradicate the understorey in woods – everything from bramble to young coppice and low branches of older bushes – and this is the habitat for many woodland species, from warblers and nightingales to dormice and butterflies. Consequently, there is a demand for monitoring to assess how much impact deer are having, and it is now a requirement of the grant that RSPB receives for managing Blean Woods that we install deer exclosures. These are fenced areas four metres square, high enough to ensure that deer can’t jump in, but with a mesh large enough for rabbits to enter if they choose. Nine of these structures have been set up around the wood, and you could come across one on your strolls. In 2008-9 a few fallow deer were present in the wood for a while; I found slots in soft mud, together with the evidence of young coppice, particularly hazel shoots, that had been nipped off a foot or two above ground, and there were two reported sightings of a deer. It seems on that occasion that the animals moved on, and there has been no suggestion of their having returned. Should a population get established in Blean Woods, there are three main options, none of them palatable to the owner of any nature reserve: do nothing and witness the decline or even extinction of our nightingale population; install extremely expensive fencing around all the coppice plots, which would lead to all sorts of access problems while leaving open the risk that a tree falling onto the fence could provide an entry point for the deer; or employ marksmen to cull them, with all the safety and animal welfare concerns that would raise. It seems to be a question of when, rather than if, deer colonise the wood, so the RSPB will have to face up to the dilemma one day.
Michael Walter
michaelwalter434@gmail.com
01227 462491
One of the deer exclosure plots in Blean Woods