Category Archives: clearance

Trail cameras

There is a lot of wildlife on Ardnamurchan. It is one of the reasons I returned here time and again … and came back more permanently in 2018.

Some of the wildlife is obvious.

Siskin (male)

Siskin (male)

The never-ending parties of tits, siskins and finches on the bird feeders.

A white tailed eagle effortlessly gliding along the scarp slope of Beinn Bhuidhe.

The stag ghosting away in your peripheral vision as you drive back late along the B8007. Did you really see it at all?

An otter rolling amongst the bladder wrack exposed at low tide as it searches for crabs.

Otter, Loch Sunart, Glenborrodale, October 2018

Otter, Loch Sunart, Glenborrodale, October 2018

But most of the wildlife you never see because it is about when you’re not.

Either the wildlife makes itself scarce when we’re blundering about … or because it’s the middle of the night.

Smile, you’re on candid camera

But with a bit of technology, some patience, a bit of trial and error and a little luck you can see what you’re missing.

Trail cameras (also know as trailcams or camera traps) are movement-activated cameras that record still images or short videos any time of the day or night. During daylight hours they record colour images. At night they use infra-red LED lighting and record in black and white.

I’m using camera traps to detect the wildlife I don’t see because I’m chainsawing out the rhododendron and making a mighty ruckus.

And I’m using them in the vain hope that they’ll help identify the gaps the undesirable wildlife get through to eat the native flowers and trees I’m planting in the newly rhododendron-free areas ūüôĀ

Red deer hind scouting out a rhododendron-cleared area for newly planted trees

There are dozens of makes to choose from at prices ranging from ¬£25 to at least 20 times that, depending upon the features required. The more expensive models have 4G or wifi built in (and I’ve no experience of these).

Optically – at least from the technical specifications provided by the manufacturers – trail cameras above ¬£150-175 don’t improve very much. Less expensive models tend to offer lower resolution and longer trigger times (I’ll discuss the significance of both of these shortly).

It’s worth noting that none of these ‘hobbyist’ camera traps are going to produce stills or video to compete with the sort of stuff you see on Seven planets, One world¬†1.

However, they can produce perfectly acceptable results.

Roe deer buck

I’ve used the Browning Recon Force Advantage and Browning Spec Ops Advantage¬†cameras.

Yes … the names are totally ridiculous ūüėČ

I felt like I should spend the weekends disguised as a bush, or at least be wearing a camouflage hat and jacket, when I ordered them over the phone 2.

Resolution

Both these trail camera models deliver still images of 4 – 20 MP (megapixels).

This is nothing like as good as it sounds I’m afraid. This is because the larger images are¬†interpolated when they’re scaled up – effectively adding pixels as the image is expanded.

I’ve only tested the still camera function during daylight and can see no significant quality differences between 4 MP and much larger images.

Do not expect images comparable to your digital SLR … they’re not even vaguely close.

Video is better being up to 60fps 1920 x 1080p HD 3. This is perfectly acceptable and I usually use them at 30fps to save SD card space.

Less expensive models usually offer lower video resolution and/or a lower frame rate. Both reduce the quality of the resulting video, though perhaps not so much it actually matters.

Lights, camera, action

Well, lights, battery life and action.

To work at night the camera needs to illuminate whatever it has picked up using the motion-sensitive sensor. It does this using infra-red LEDs. The two cameras (embarrassingly) named above use different types of LEDs.

The Recon Force Advantage has ‘low glow’ IR LEDs. These are visible to the human eye and they are certainly visible to animals (as I regularly capture video of them reacting adversely to the light).

Badger – note the surprise when this¬†poorly-sighted fellow sees the ‘low-glow’ LEDs

The Spec Ops Advantage has ‘no glow’ IR LEDs. These are essentially invisible to humans 4, but are effective over a shorter range (~70% the distance of the low glow LEDs).

The other significant feature to look for in a trail camera is the trigger speed i.e. the time it takes from detecting motion to capturing video (or a still  image).

0.4 seconds might not sound very long, but a small animal – like a stoat – moving fast across the field of view will feature for a further half second on the video before you get 10 – 20 seconds of just herbage waving in the breeze.

Mouse … one of several hundred I have videos of ūüôĀ

Both cameras use eight AA batteries. Unfortunately, not just any old AA batteries. You’re strongly recommended to use lithium AA batteries which are appreciably more expensive 5.

Why lithium? You need batteries capable of delivering high current – at least 2500mAh – and they often need to work at low temperatures. Standard rechargeables or Duracell simply cannot do this.

I get 9-12 months use out of a set of lithium batteries in a well-placed camera (i.e. not too many false triggering events) set to take short videos, about 50% of which are recorded at night. So, although the batteries are not inexpensive, they also last well.

I’m also dabbling with building a solar-powered rechargeable battery pack, though this will only be suitable for areas which receive full sunlight at least some of the time. It will make it less portable, but might be worthwhile for a really good location (or a very remote one).

Irrespective of the technical details of the camera trap, the biggest influence I’ve seen on actually capturing useful and usable images is due to the positioning of the camera.

Location, location, location

Firstly, things to avoid …

  • Glare from the sun. Try and position the camera facing north. Or at least somewhere in the arc between north-east and north-west. Not an issue at night of course, but why compromise daytime images beings spoilt by glare and dazzle? 6
  • Herbage moving close to the lens. This will repeatedly trigger the camera during windy weather. There’s only one thing less interesting than screening 89 short videos containing the same small branch being blown intermittently in and out of the field of view.
  • Mounting the camera on something that moves. This almost always ensures lots of false triggering. Even 8-10″ tree trunks sway perceptibly in strong wind. A fencepost is good, as is a tree-stump 7.
  • Mice. This is what’s less interesting. That infuriating branch I just mentioned is insignificant when compared with a couple of hundred ten second videos of mice scurrying around in the foreground ūüôĀ

Red deer stag and glare from poorly positioned camera

Obvious places to try …

  • Game trails. Large animals usually leave a track or trail, particularly if the ground is soft. I usually point the camera along the trail to get a head-on (or tail-on!) video, rather than a fleeting glimpse as they cross the field of view.
  • Paths. Many animals will follow man-made tracks rather than making their own way through the undergrowth. This is where I’ve had most success in filming a wide range of wildlife – from badgers to woodcock.

Roe deer hind on manmade ‘path’ hacked through the bracken

  • Bait. I’ve not tried this but you’ll see many camera traps set up pointing at bait of some sort. Some people use an egg, others use cat food or – for pine martens – a digestive biscuit with jam.
  • A waterhole. Don’t expect hippos and gazelle, but you might well get an otter or animals coming to drink. I don’t have anywhere really suitable so can’t comment on how effective this is.

The camera should almost always be mounted 30-60cm above the ground. Most trail cameras have a small screen you can use to check the positioning. If the camera is only 30cm from the ground this can be tricky to view 8.

Try to position the camera vertical and avoid too much sky in the field of view. The former makes the resulting videos/photos look a bit better quality and the latter avoids lots of ‘blown out’ highlights in the images.

Trail camera firmly strapped to the lower trunk of a tree

The great thing about these cameras is they’re pretty much ‘set and forget’. You can leave them for a week or a month. You certainly don’t need to check them on a daily basis. They just sit there, quietly grabbing images when triggered.

SD cards

Camera on game trail

All of the images are recorded onto full-size SD cards. I only use 16 or 32 Gb cards and have only ever run out of space when I setup the camera incorrectly and recorded very long video clips.

With 16 or 32 Gb SD cards now costing only ¬£6-8 it’s easy to carry spares and swap them with the SD card in the camera. I’ve also built a portable, battery powered, Raspberry Pi Zero backup device which copies the card in situ. However, this gets press-ganged into other roles and, frankly, it’s faster to just swap cards over.

Absence of evidence is not evidence of absence

The two most obvious signs that badgers are in an area are their extensive latrines and their corpses at the side of the road ūüôĀ The badger (above) was the first I’d seen on Ardnamurchan and I had no reason to suspect they were there.

The camera never lies.

Pine marten, Ardnamurchan, May 2018

In contrast, it’s not uncommon to see pine martens lolloping across the road and their scats (faeces) are often left in prominent places 9.

Pine marten scat

Of course, the ‘biggy’ in terms of mammals on Ardnamurchan, is the Scottish wildcat. Although this area was designated as a wildcat ‘haven’ about 5 years ago, things have gone a little quiet since then.

Scottish Wildcat Action are now concentrating on Morvern which, although not far away, is across Loch Sunart and likely forms an isolated population.

Nevertheless, over the next year or so I’ll continue to leave at least one or two trail cameras well away from areas of human disturbance in the hope of capturing one on video.


 

Are you sitting comfortably?

The heady combination of hills, lochs and ever-changing light make for some wonderful views on Ardnamurchan. This is obvious from some of the dawdling rubberneckers on the tortuous B8007. Far better to stop and take in the view properly than to drive with one eye on the scenery and one on the next blind corner.

And once you do stop it’s good to sit.

Isle of Carna, Loch Sunart

Relax. Why rush?

And the same applies when you reach the end of your journey.

Sometimes I sits and thinks, and sometimes I just sits

Our plot is south-facing, partly wooded and heavily overgrown with rhododendron. However, between the trees and over the rhododendron there are some great views of Loch Sunart, the hills of Morvern and Рlooking north and west Рthe Ardnamurchan hinterland.

It’s good to sit and watch the world and the wildlife go by, to see the yachts and fishing boats on the loch and to listen to the birds and the wind in the trees and … little else.

You can sit and think things through, or just sit 1

But don’t rely on being able to sit on the ground. The climate in Ardnamurchan is mild and wet. At times very wet. The annual rainfall exceeds 1700mm and so the ground is often damp.

So you’ll need a chair, or a bench or a thoughtfully-placed log.

Sometimes I sits and thinks, and sometimes I just sits

Having carried a collapsible chair around the plot a few times it was clear where the likely spots were to place a more permanent seat.

Now all I had to do was find some suitable wood.

Larch

Totem pole

Did I mention it can be wet in Ardnamurchan?¬†Anything left out in all weathers needs to be rot proof. Teak is the obvious choice but I’d prefer not to contribute to the further destruction of Myanmar’s tropical forests.

Something closer to home was needed.

Aside from the ubiquitous birch, rowan, hazel and oak there are a number of larches around the site. One of these had been topped and limbed (albeit rather crudely).

It was a favourite spot for the greater spotted woodpecker but it was also a bit of an eyesore.

It intruded into some of the better views and looked like a totem pole. I even briefly considered tidying it up in situ and producing some chainsaw garden sculpture from it.

Instead, I felled it.

It was growing from a very steeply sloping bank and necessitated a rather precarious stance, but the combination of my Trusty Husky and a plaid shirt soon had it down.

Larch (Larix decidua) is a deciduous conifer introduced to the UK in the 17th Century 2. The needles turn a lovely yellow in autumn before being dropped and are then replaced with fresh, bright green growth the following spring.

There are two other notable things about larch. In my experience it generates some of the smallest and most irritating splinters when freshly cut. Gloves are essential. More importantly, it exhibits good resistant to rot, so was ideal for my purposes.

Ardnamurchan chainsaw massacre

The tree was about 35 years old and far too heavy to move without some more attention from the chainsaw. Having properly tidied the side branches protruding from the ~6-7 metre trunk I cut it into suitable sized logs. Then, using a combination of brute force and lashings of ignorance, I manhandled them to a flat area to construct some log benches.

Larch garden bench

You weren’t expecting fine furniture were you?

Having created a couple of notches in the trunk I rested it on two cut logs and then levelled the top off to create a flat area to sit on. The resulting bench was very sturdy, pretty stable and exceedingly heavy. It also left me with half a dozen infuriatingly small and itchy splinters …

Little and Large

Having made one I then made a second slightly smaller log bench with the ‘leftovers’.

Location, location, location

I made two log benches as I’d already identified two positions with contrasting and rewarding views.

The first was on a¬†rocky outcrop backed with light woodland, which commanded good views to the north west. It’s relatively sheltered from the east and is in dappled shade until the afternoon.

Somewhere to sit and think

I managed to carry the smaller bench up to the rocky outcrop unaided, with several rests to breathe look at the view.

The larger bench was much too heavy to lift and was to be located further away and – critically – further up the hill. So, having chosen to install it on the warmest part of a sunny June day (D’oh!), I laboriously lifted it, end-over-end, up and up and up the hill.

About an hour and three pints of sweat later I’d got to the top having inadvertently discovered a wasps nest in the undergrowth. They didn’t take too kindly to me thudding past with my carefully handcrafted bench.

But it was worth it …

The perfect place for a cup of coffee or glass of wine

There are panoramic views over the islands (Risga, Oronsay and Carna) in Loch Sunart, the hills of Morvern to the south, and to Ben Hiant, Mull and Coll to the west.

Time for a rest …


Notes

The splinters that freshly-cut larch generates are very quickly rubbed away and the benches are perfectly safe to use without wearing gloves (or reinforced trousers).

A good guide to tree identification is Collins British Tree Guide (ISBN 978-0-00-745123-4) by Johnson and More. For more information on the propagation, growth, uses and lore of Scottish trees I recommend¬†A handbook of Scotland’s trees (ISBN 978-190864382-7) edited by Fi Martynoga.

If you want to know what you can see from any point on earth I recommend the HeyWhatsThat horizon plotter website. Quoting directly from the site this¬†computes the horizon and mountain names and other related visualizations, including the surface of the Earth visible from where you’re standing (the visibility cloak or viewshed) and the line of sight profile between you and the distant peaks”.

For example, here’s the map of what’s visible from the top of Ben Hiant …

HeyWhatsThat horizon map from Ben Hiant, Ardnamurchan

 

Don’t forget your roots

Having discussed the Triffid-like rhododendrons that infest parts of Ardnamurchan and the tools needed to clear them, here’s a further instalment showing how to ensure they don’t re-grow.

Rhododendron (Rhododendron ponticum) are relatively shallow-rooted woody shrubs. They can spread by wind-dispersed seed and by suckering. Suckers are more correctly termed basal shoots and emerge from the root system.

Dense rhododendron growth with no understorey

Dense rhododendron growth with no understorey

Each of these suckers essentially has the ability to form a new plant.

If you cut a rhododendron to near ground level – leaving just enough of the woody stump to trip over ūüôĀ – it will usually produce new growth.

Even if it doesn’t produce growth from the stump, it will almost certainly generate suckers from which large new plants will eventually grow.

Consequently, simply cutting rhododendrons to the ground and leaving the roots untouched results in dense multi-stemmed thickets forming.

Multi-stemmed rhododendron from suckering

Multi-stemmed rhododendron from suckering

Therefore to ensure the rhododendron does not re-grow you must kill the roots of the plant. There are a variety of methods that can be used to achieve this, some faster than others.

Environmentally friendly methods – efficacy unknown

You can cut and clear the rhododendron and then periodically return to the stumps and, using something like a hammer, smash down the re-growth. Over a period (perhaps a long period) the stump will be killed.

There is an approach called the¬†‘lever and mulch’ method in which the shrub is cut down and the amputated top growth is used to cover the stump, effectively starving any new growth of light.

I’ve not tried either of these methods – I don’t have the time and want the site cleared – and so cannot comment further on them.

Environmentally unfriendly methods

A very common approach is to cut down the plant and then return after it has re-sprouted to spray with a systemic weedkiller such as glyphosate (in commercial products Roundup or Gallup).

Spraying requires a dry relatively calm day. If it’s wet and/or windy the weedkiller will either be less effective or may damage other plants.

Ardnamurchan has fabulous weather but it’s not always suitable for spray treatment ūüėČ

I’m also not keen on the relatively indiscriminate application of weedkillers so have not used this method.

Drill and drop

What’s needed is a method that applies a weedkiller such as concentrated glyphosate in small amounts¬†precisely where it is needed.

This can be easily achieved using stem injection.

The method is simplicity itself. A 10mm hole is drilled near the base of the trunk and 1-2ml of strong weedkiller is applied directly into the hole. The weedkiller is transported throughout the plant and, over a period of weeks or a few months, the plant is killed.

Once the plant is dead it can be cut down and burnt.

For pretty-obvious reasons this method is known as drill and drop.

Birds-eye view of a multi-stemmed rhododendron drilled for glyphosate application

Birds-eye view of a multi-stemmed rhododendron drilled for glyphosate application

Notice the holes an inch or two above the leaf litter in all the major stems. Why, if¬†‘… the weedkiller is¬†transported¬†throughout the plant …’¬†does every stem have to be drilled?

That’s because I oversimplified the method. The weedkiller appears to only kill the top growth and root of the individual sucker. It’s not entirely clear why. I presume that the new growth establishes its own root system over time (some of these stems are 2-3″ in diameter and 15-18 feet long) and that the weedkiller only spreads systemically within this new growth.

Consequently every stem must be drilled … and some will be missed 1.

Therefore, there is another method that can be used …

Drop and drill

You cut the plant down first, drill the remaining stump and apply the weedkiller. This approach has the advantage of immediacy. There’s no waiting for the rhododendron to die. It also has the advantage of thoroughness. Since you’ve cut all the top growth down you cannot inadvertently miss any of the stems.

Drop and drill

Drop and drill

The additional advantage is that you are generally drilling from the top into the stump. It’s easier to generate a clean hole and there’s even less chance of spilling weedkiller.

Driller killer

A battery-powered portable drill with a 10mm wood bit is needed. If the rhododendron growth is very dense or very extensive or – in my case – very dense and extensive ūüôĀ then it’s worth having a spare charged battery or two so you aren’t forced to stop just as you’re beginning to have fun.

The hole needs to be 2-5 cm deep. It is best drilled at an acute angle to reduce the chance of excess weedkiller running down the stem onto other plants. One hole is generally sufficient, even for the largest stems.

Stems as narrow as 2 cm in diameter can also be drilled. Choose a place where the growth is horizontal – close to the original stump – and drill a 1 cm deep hole, filling it with weedkiller to just below the brim.

Choose your poison

The weedkiller I use is Gallup glyphosate. Bought in bulk this costs about ¬£20 for 2 litres. Because you’re applying a very small amount to a single, potentially very large, plant it needs to be used quite concentrated. I’ve used it at 20-25%¬†i.e. mixed 1 in 4 or 1 in 5 with water.

Prepare a stock solution in a well-labelled plastic bottle. Don’t make up much more than you need as I’ve read it degrades over time and so loses efficacy. I make up 250ml which is enough for a very rewarding afternoon of rhodo-poisoning.

Trickle 2 container for delivery of glyphosate

Trickle 2 container for delivery of glyphosate

Administering 1-2 ml to a small hole in the base of a drilled stem requires a steady hand and a bottle with a nozzle that doesn’t drip or leak. I’ve used what a beekeeper would know as a Trickle 2 oxalic acid bottle. These probably have a proper name, but I’ve no idea what it is.

The bottle has a 100 ml reservoir and a small upper chamber that takes 5 ml. It has a twist-lock nozzle and doesn’t drip. It needs to be refilled every 50 or so stems. Remember you’re probably using it on your hands and knees in dense undergrowth. A refill is a welcome opportunity to stand up and stretch.

Drill and drop vs. Drop and drill

In practice I’ve found I have to use a mix of the two approaches. Each has advantages and disadvantages, but both are usually needed.

Drill and drop is great because the killed shrubs are much lighter to cut down, easier to transport and burn faster. It takes about 3 months for the plants to die – the upper growth withers and finally drops off.

The disadvantage of drill and drop is that you need to get to the base of the stems in very heavily-overgrown areas. Almost inevitably this means crawling about, working in confined dingy spaces and involves encounters with brambles, wasps nests and sharp pointy things.

Wear safety glasses.

New growth retrospectively drilled and killed

New growth retrospectively drilled and killed

Almost inevitably you’ll miss some stems. Drop and drill has the advantage of immediacy. You cut the plant down and then drill and poison the stump. You gradually work your way through a dense thicket, but the drilling and glyphosate delivery is done in an already cleared area so is much easier.

Slash and burn

I prefer to drill the plants, let them die back, cut them all down and return to ‘mop up’ the remainders I missed the first time round. I usually carry a pen to mark stumps cut down ‘live’ that need retrospective treatment 2. This avoids double-dosing.

If you cut the trunk near but below the previously drilled site the woody interior of the stem is usually stained distinctively, so you can avoid re-dosing it.

Waiting for the inferno

Waiting for the inferno

The side branches and top growth are removed with a billhook, stacked up and subsequently burnt.

Towering inferno

Towering inferno

The main stems are cut up and dried for firewood.

Something for the winter

Something for the winter

That lot is about half what I prepared from the 1600 m2¬†(i.e. 40 m x 40 m) area I’ve cleared so far.

Glyphosate – mode of action and toxicity

Glyphosate is a broad-spectrum (i.e. indiscriminate) weedkiller that inhibits the plant enzyme 5-enolpyruvylshikimate-3-phosphate synthase. This enzyme is critical for the synthesis of the aromatic amino acids tyrosine, tryptophan and phenylalanine. Production of these amino acids is important during plant growth which explains why glyphosate only kills growing plants.

Glyphosate was discovered by Monsanto, given the trade name Roundup and first used for agricultural purposes in 1974.

It is adsorbed through the leaves, through drilled or cut stems but only poorly through the roots. Stem drilling, or stem injection, is a much more effective way of administering glyphosate than simply painting it onto a cut stem; there is less wastage and much less potential for collateral damage.

Glyphosate has low acute toxicity and a half-life of about 47 days in soil.

Glyphosates and cancer

Glyphosate is extremely widely used. Consequently, residual amounts are sometimes found in food products. The levels are very low, with over 99.5% of nearly 7000 food products tested in 2016 having less than the maximum allowed residue levels.

However, the very widespread use and potential long-term exposure to low levels of glyphosate mean that it has repeatedly been associated with causing human cancers. Monsanto (now Bayer) have recently lost a court case when sued by a an individual who had developed non-Hodgkin lymphoma, claiming it was caused by long-term exposure to high levels of glyphosate while working as a gardener. Monsanto is appealing against the decision.

The scientific evidence¬†(a very different level of ‘proof’ to a law court) supporting glyphosate being a carcinogen is very limited and equivocal.

A long-term (decades) study of 55,000 people showed that there was no increased risk of cancer in those exposed to higher levels of glyphosate.

Very recently a¬†meta-analysis¬†(a statistical study of other studies) has linked exposure to very high levels of glyphosate to non-Hodgkin lymphoma. Despite the headline figure being a scary 41% increased risk 3 of developing non-Hodgkin’s lymphoma the¬†absolute risk was only about 0.5%. And this was only for people exposed to very high levels over a very long period.

The headline 41% figure sold some newspapers, but the coverage was probably distorted and ignored or selectively over-interpreted much of the scientific evidence.

There’s wasa good account of this subject on the¬†More or Less podcast recently.

Nevertheless, I always take care when using glyphosate. I wear disposable nitrile gloves and safety glasses. I administer small doses (1-2 ml) to the drilled holes, avoid spilling it and wash my tools and hands carefully after use.

A blank canvas

Before

Ardnamurchan or Borneo?

Ardnamurchan or Borneo?

After

Cleared and ready for native tree planting

Cleared and ready for native tree planting

There’s still more to do (measured in acres not m2) but after a bit more clearing this area will be planted up with native trees in the 2019/20 winter.