Desire Lines and Old Habits
I arrive at Wilderness Wood on a Tuesday morning for a change, as I can’t make Wednesday conservation volunteers this week. I immediately become the object of derision between Jake and Mike who observe how instead of following the new road into the wood yard, I stick to the course of the former road, walking from the car park across bare soil.
It is an interesting and appropriate start to the day since desire lines and doing things out of habit are part and parcel of nature. People are part of nature so I reckon my inability to follow the prescribed new route into the wood yard is a badge of honour.
“We’ll have to put a fence in the way then.” Suggests Jake.
He is right. That would force me to change my ways. Likewise, faced with a new barrier, nature inevitably shifts its desire lines, which then becomes a new habit. One way or another nature will always learn to find the most advantageous route between two points.
My trusty spade in hand I head off along my usual desire line between the wood yard and where I intend to work today - Bat Park.
Then I have a change of heart, as I want to check for orchids in Orchid Glade. This takes me across Middle Paddock where I encounter a pair of very large deer. These are the brainchild of artists in residence Simon and Martin and are made of woven hazel and willow.
Two oversized deer have taken up residence in Middle Paddock, fortunately these are just sculptures
Deer are becoming increasingly significant in our decision making at Wilderness Wood, a bit like climate change. You can’t ignore the reality of either. Some will tell you there is no such thing as a climate emergency, but then science proves otherwise. I had a friend once who declared that he didn’t believe in science, as though it was Santa Clause. I suppose that’s why they say that ostriches bury their heads in the sand (they don’t really do that, but it’s a useful metaphor). Likewise, we can’t ignore the impact of deer. Because of their increasing numbers around the wood we have had to erect a 6 foot high deer fence around Bat Park and have put tree guards on all newly planted trees. It is patently not enough.
I’m not sure if Simon and Martin’s deer are designed to scare off other deer (like plastic herons in your fish pond), or attract them (like plastic ducks on a decoy pond). In reality they are designed to do neither. They are there to stimulate thought and to me they ask a question: “What are we going to do about the deer problem?”
When I arrive at Orchid Glade the first thing I notice is not orchids (too early in the year for them), but deer ‘desire lines’ converging on Middle Paddock from different points in the wood. This is significant because it says that Middle Paddock is an increasingly popular place for deer to gather, despite its proximity to man. They are no longer afraid of us and come in such numbers (probably after dark) that their hooves have worn bare pathways through the grass and other vegetation to get to the good grazing at Middle Paddock.
Black lines mark the converging deer desire lines through Orchid Glade (marked on the ground by hoof prints)
Whilst I’m here I make a mental note of other mammal activity: A rabbit burrow (complete with tell-tale droppings), mole hills and a scrape in the soil made by a rabbit, badger or fox. All live in or around the wood so their signs are unremarkable. Their numbers are not significant for the most part, although the rabbit population does sometimes give cause for concern.
Since there are no orchids to record I return in the direction of Bat Park, although my desire line has now changed a little with my new starting point at Orchid Glade.
At Bat Park I emerge from the shade of the woodland trees into the bright, warming sunshine of this area of open grassland. My mission however is to dig it up. Well that’s perhaps overstating my intentions. I’m here to dig up a number of heather plants growing in the grassland at Bat Park because they too could soon be an issue. The problem with Common Heather (Calluna vulgaris) in our acid lowland grassland habitat is that it could eventually come to dominate the grassland and turn it into heathland. One solution to this is to mow it, as mowing favours grasses and low growing herbs over woody stemmed plants like heather. Another solution is to graze it, either naturally through rabbits, or with sheep. The former have been rejected as they are difficult to control, whilst the latter involves the challenge of managing their welfare.
Our chosen solution though is more elegant. We want the heather to grow in the adjacent area of Bat Park, dedicated to heathland habitat. So all we need to do is dig up the heather in the grassland and transport it 50m to the heathland site, where we can dig a hole in a patch of bare ground and replace the soil with a freshly dug heather plant. This is a win-win situation with the grassland acting as a kind of heather nursery.
I take my trusty spade and start digging. The shallow soil of the grassland is underlain with bedrock so the plants are shallow rooting and I am able to dig one out with ease. Ideally we need to dig the bigger heather plants first since these have masses of seed heads, so are likely to scatter these in their new heathland habitat where they are wanted and away from the grassland, where they are not.
A heather divot is removed from the grassland ready to be transplanted into the heathland area of Bat Park
I have a further bright idea, which is to dig up a young birch tree growing in the heathland and put the heather plant in its place. Birch are a bit of a weed in heathland, so this action kills two birds with one stone (in reality only one tree is killed – but you know what I mean). We have now achieved a ‘win-win-win’ situation, about which I am immensely pleased as it saves on labour. Next Stewardship Saturday I hope to attract a number of volunteers to join me and move 100 heather plants in a couple of hours. A significant contribution towards our slow but steady development of our non-woodland habitats at Wilderness Wood.
Ideally this operation is carried out before it gets too hot and dry, so the heather has a fair chance to root in its new home. Early April will probably be the latest we can reasonably do this. The whole operation not only moves heather to where it is wanted and away from where it is not, but the creation of patches of bare soil in the grassland is also beneficial. As I dig, a robin follows me doubtless gathering invertebrates disturbed by my activity. Likewise, moving soil is beneficial as it potentially spreads seed from one site to another. The grassland Minotaur Beetles also appreciate this newly disturbed and bare ground, to dig holes of their own.
Minotaur Beetles were discovered at Bat Park in 2024. They are quite rare and important soil invertebrate
After moving a dozen heather plants I’m ready to take a rest in the bright sunshine on a nearby south-facing sunny bank. A number of solitary bees are also buzzing around here for suitable locations to make burrows for egg laying and rearing their larvae. This is a prime location since being on a south facing slope it provides for a nice warm, dry substrate with less risk of waterlogging of their burrows. It is noteworthy that the solitary bees don't reuse holes dug from last year. I suspect this is an evolutionary development that they have inherited from successful parents, since old burrows are quite likely to have unwanted parasites in them from the previous year’s occupants. Currently the bees are not aggressive, but if they are anything like their counterparts in my own garden, they certainly will be once they have laid eggs. Old habits, including desire lines that work will only really change once a better course of action is found.
I return for lunch, but afterwards spend an extra 90 minutes addressing one aspect of the deer problem, back in Middle Paddock. Two weeks ago I planted a black poplar sapling donated by Kew Gardens, at Wakehurst Place. The tree guard I put around it will soon be too small, so I set about creating a woven deer guard which should enable the tree to grow tall enough to avoid their sharp incisors, which have done so much damage to many of the hedges planted over the last few years.
A biodegradable tree guard created to protect one of our new Black Poplar saplings from deer grazing
Deer guards are only a temporary solution, with more drastic measures being considered to make the deer change their habits and encourage them to find new desire lines away from Wilderness Wood.