The latest report from Michael Walter:
One of Blean Wood’s hidden gems is its heathland and, if you’ve visited the reserve, you’ll no doubt have followed a waymarked trail through a two-hectare heath. Delightful though this is, especially in late summer when all the heather is in drowsy, honey-scented bloom, it is quite a small area. A second heathy block, six times the size, is tucked away down the track leading to the A2. Even this is very small beer when contrasted with Ashdown Forest or the New Forest, but it is big enough for management by grazing to be a realistic option, and nearly 15 years ago the RSPB embarked on an experiment with livestock, initially bringing in 22 Soay sheep and 18 goats, all on loan from a very obliging Kent Wildlife Trust. Half of the sheep and all the goats had to be returned to the Trust later that year, compensated for in 2006 by the addition of two konik ponies to the menagerie. Although the sheep and ponies were both hardy, primitive breeds, they were primarily grazers (flesh-and-blood lawn mowers) whereas what we really needed were browsers, such as goats - animals that would control woody plants, particularly bramble and the very invasive birch, by regularly nibbling off their leaves. The sheep gradually died of old age, and in 2017 the ponies were returned to the Trust, leaving the way open for a programme to build up a flock of goats, starting with five endearing little Bagot kids – not children from a little-known Midlands town, but young black-and-white goats of an ancient breed. Too small to be commercially valuable, they are hardy, self-sufficient animals, which makes them ideal for conservation work, where conditions may be tough in winter. Those initial pioneers are now full-grown and, with the gradual addition of more animals, the flock today stands at 19, with enough chomping jaws to start making an impact on the ubiquitous birch. Despite the legendary tales of their catholic tastes in food, goats are actually quite fastidious, preferring young birch and bramble leaves in summer while in winter, when the options are fewer and less appealing, they have to brace themselves to tackle gorse and nutrient-poor heather. They do have one trick up their sleeves though, and that is to make use of their chisel-like incisors to gnaw away at the bark of young trees up to 20 feet tall, and recently they have had a fine time chewing the trunks of numerous alders that form a line down a tiny stream. What some might consider desecration of the trees can’t easily be hidden, as the wood turns quite a striking orangey colour on exposure to the air, announcing to the world the vandalism inflicted on them. But what is the appeal of bark-stripping? The bark itself is a dry, largely dead layer with minimal nutrient value and difficult to digest, but what the goats are seeking out is the phloem, which forms a narrow layer immediately below the bark. Sugars that have been produced in the leaves during the summer are transported through the long pipe-like cells of the phloem to wherever they are needed, so, although photosynthesis grinds to a halt when the leaves drop, the phloem tubes remain juicy, and thus highly desirable to animals that are otherwise restricted to a boring winter diet of tough, tasteless vegetation. If the bark is stripped off all the way round the stem, it may lead to the death of the tree above that point; fresh shoots can still sprout from near ground level but, being readily accessible to the goats, this young growth will be promptly eaten back, leading to the eventual demise of the tree.
Although we’ve passed the winter solstice, we may be kidding ourselves that spring is coming, but there is hope, in the form of dangling hazel catkins, if you know where to look for them, and singers include great tit, song and mistle thrush, robin and stock dove, all currently receiving a severe battering from Storm Brendan.
Michael Walter
michaelwalter434@gmail.com
A Bagot goat eagerly stripping off alder bark to get at the underlying phloem
The goats’ impact on a cluster of alder stems