Originally published in Devon Life magazine, March 2013
Nature has a way of looking after itself. You leave it alone and it usually does just fine. If, however, you start adding things that shouldn’t be there, the results can be catastrophic. The British countryside is full of examples and East Devon is no exception. Here, we look at the price we have paid for our own interference and what is being done on the Escot Estate to redress the balance.
The North American grey squirrel was introduced to Britain in the late 19th century. Since then, the rapid spread of the grey squirrel has been accompanied by a corresponding decline in the red squirrel population, for a number of reasons. Greys are able to digest certain tree seeds much earlier than red squirrels and reds will also only eat certain fruits when they are fully ripe, whilst greys are not so particular. This means that when food is bountiful for grey squirrels, it can often be scarce for reds. Disease is another serious issue; red squirrels are susceptible to a deadly virus known as squirrel pox or parapoxvirus, which is known to be spread by grey squirrels that, unlike reds, are immune to its effects.
Visitors to Escot Park, near Ottery St Mary, can’t fail to notice the Red Squirrel Encounter, opened last year to highlight the plight of this iconic British mammal. The walk-through enclosure, with its larger-than-life interpretation boards and daily talks by Escot’s Nature Rangers, is designed not only to allow visitors to encounter this elusive species but also to bring to visitors’ attention the seriousness of the situation now facing the red squirrel. It also, of course, provides sanctuary from contact with greys.
This Project is part of the larger ambition of the Red Squirrel Project South West (RSSW) initiative to eventually return reds to the wild in the south west and, with this in mind, phase two of the Escot project will see the development of a red squirrel breeding centre.
In 1929, mink were brought to Britain from America to supply the fur trade. A large number of escapees meant that by the mid-1950s mink were known to be breeding in the wild and by the late-1960s could be found in more than half the counties of England and Wales as well as parts of Scotland. This situation was exacerbated in the 1990s when huge numbers of mink were liberated from fur farms by animal rights activists.
As in the case of red and grey squirrels, it is no coincidence that the rise of the mink corresponds with a sharp decline in the population of the water vole. Since the 1970s the water vole population has dropped by an alarming 95%, with predation by mink responsible for wiping out water voles completely in many areas. Habitat loss is another major factor in the decline of the water vole and combined with the presence of mink is a recipe for disaster.
The River Tale runs through Escot on its way to join the River Otter at Ottery St Mary and the estate works closely with the Tale Valley Trust (TVT) to conserve this beautiful part of East Devon. The work of the TVT has seen the implementation of management techniques that work with, and for, the local wildlife. This has included protecting the banks from grazing livestock, therefore increasing bankside vegetation and preventing erosion and damage to nest sites. Water meadows have been restored and the river has been monitored for the unwanted presence of mink. Research suggests that water vole and mink can co-exist where there is sufficient suitable habitat and it now appears that the Tale’s water voles are thriving despite the occasional visit from their most deadly predator.
It is not just the introduction of alien fauna that has wreaked havoc along our rivers and streams. In 1839 a beautiful relative of the Busy Lizzie, collected by Kew Gardens, escaped to the wild from their greenhouses. Himalayan Balsam (Impatiens glandulifera) has since had a devastating effect on wildlife habitats, clogging rivers and out-competing indigenous species, far better suited to sustaining our wildlife. Knowing that each plant is capable of producing up to 800 seeds, TVT volunteers meet up each July to remove all traces of Himalayan Balsam from the length of the River Tale in the hope of slowing its spread and drastically reducing its impact on the river and its inhabitants.
H.G Wells once said “Adapt or perish, now as ever, is nature’s inexorable imperative” but, in the meantime, it is man who must change in order to put right his past mistakes.