A day at Dog Falls

At the end of June I went up to Glen Affric for the day, intending to visit Glac Daraich, the site of the third fenced exclosure in the glen that we funded in partnership with Forestry Commission Scotland, back in 1993.  However, it was one of those days when I decided to stop for a quick look at the forest near Dog Falls on the way into the glen, and I ended up spending the whole day there never making it to my destination …

I stopped near the falls themselves, and as soon as I stepped out of my car, I spotted something of interest – a couple of flower spikes of common wintergreen (Pyrola minor). This is a typical plant of the Caledonian Forest, and while it’s not rare, it is relatively uncommon to see it. These plants were in their prime flowering stage, so I got my camera out immediately to photograph them.

 

 

 

 

 

 

 

The individual flowers on each spike are almost spherical, and are pinkish-white in colour, making them quite distinctive and different from the other common flowering plants in the forest. They must have been flowering there regularly, as I also noticed an old dried flower spike, which must have been from last year. I’ll visit this site again next summer, to see if they flower again.

 

Just next to the wintergreen plants, there was a young Scots pine (Pinus sylvestris) seedling, and it was covered in the froth or ‘cuckoo spit’ produced by the larvae of the common froghopper or spittlebug (Philaenus spumarius). This is very abundant at this time of year, and can be seen on heather, blaeberries and other herbaceous plants in the forest.

Just behind the pine seedling, I spotted something on a bracken plant (Pteridium aquilinum), and looking closer I saw that it was a moth. I didn’t recognise the species, but it seemed quite content to stay motionless on the bracken, so I was able to get a good photograph of it, and I subsequently had its identity confirmed as being the Welsh wave (Venusia cambrica).

 

There’s a small gravel-covered clearing in this area, which used to be an small informal car park, but vehicle access to it was blocked off some years ago, and it’s now beginning to vegetate over. I’ve been observing the changes over the past years as plants colonise it, so I had a quick look at it this day as well. My eye was quickly drawn to some autumn hawkbit plants (Leontodon autumnalis) that were in flower, as I knew from the aphid survey that we had done on Dundreggan last year that there are host-specific aphids that feed on this species. I didn’t have to look too far, as one of the first few plants I looked at had aphids feeding on its stem, below the flower.

I took a number of photographs using my high-magnification macro lens, and was later able to get the aphids confirmed as being a different species (Uroleucon hypochoeridis) to the one (Uroleucon leontodontis) which I’d seen on autumn hawkbit at Dundreggan last year. It was only later at home, when I looked at the photographs in detail that I discovered I had captured the moment of birth, when a nymph emerged from its mother! Aphids are remarkable in their reproductive behaviour, with the females able, in part of their life cycle, to produce young without first mating with a male. Unlike most insects, they also give birth to live young, not eggs, and the newly-born nymphs will already have developing embryos inside them.

This combination of strategies enables aphid numbers to increase very rapidly, particularly in the spring, when the sap that they feed on is flowing strongly in trees and plants. I’ve had an increasing fascination for, and interest in, aphids in the past couple of years, so I was delighted to see these ones here, particularly when I realised I’d got some images of an aphid birth occurring. I’ve subsequently prepared a powerpoint presentation about aphids, and the birth photo is one of the highlights of that, judging by the feedback I got from the volunteers on the ‘Up Close to Nature’ Conservation Week I showed it to recently.

Crossing the road, there’s a viewpoint beside the river, looking upstream towards Dog Falls, although it’s hard to see much of the falls themselves, because of the angle of the rocks there. Only the lower-most part of the falls is visible, giving a tantalising view which hints at how much more there is to see.

 

 

 

 

 

 

While I was photographing the falls, I noticed a caterpillar that was motionless on one of the fence that forms the balustrade around the cliff edge there. It didn’t move at all during the half hour or so that I was there, and I was later able to get it identified as being of the  December moth (Poecilocampa populi). This is a fairly common species, and as its common name suggest, the adult can be seen in flight in December. The caterpillar apparently feeds on a range of deciduous trees, but its specific epithet refers to poplars, and it may be that it had been feeding on one of the aspen trees (Populus tremula) that are growing by this viewpoint – the fence post it was on was only a few feet from one of them.

 

 

 

 

 

 

 

Under the canopy of the trees near the viewpoint my attention was drawn by a cluster of hard ferns (Blechnum spicant). This is one of the commonest ferns in the forest, and its evergreen sterile fronds, which grow close to the ground, bring a splash of bright green colour to the forest floor in even the duller winter months. It also produces fertile fronds each year, and these grow more vertically, so that the spores they release can be dispersed by the wind. These fronds die back each year, and the new season’s ones were just uncurling, in a graceful slow motion natural ballet.

Just beside the hard ferns, and in amongst some fronds of bracken (Pteridium aquilinum), there were some bright blue flowers belonging to germander speedwell (Veronica chamaedrys). These have a delicate beauty to them, but can be easy to overlook, as they are small in size, and usually dispersed  – it took me a couple of minutes to find this group of four blossoms clustered together to photograph.

Leaving the viewpoint, I headed up to the falls themselves, stopping just as I reached them to look at the aspen trees (Populus tremula) growing there. I often visit these trees, and have frequently found interesting life on them – galls, sawfly larvae and moth caterpillars, to name a few. This day, I was looking at the underside of some of the leaves when I noticed clusters of tiny eggs that had been deposited there in what looked almost like a geometric pattern.

On some of the leaves, the eggs had hatched and groups of black larvae were feeding on the leaves beside each other. I suspected that these larvae, from their body shape and feeding pattern, were from a leaf beetle (Phratora vitellinae)  – a species which I’ve seen the adults and larvae of feeding on these trees in previous years. This was the first time I’d seen their eggs though, so I took a leaf with some un-hatched eggs home, and reared the larvae, feeding them on leaves from the aspen tree in my garden, until they pupated. I then sent one of the adults that emerged off to a Coleopterist (an entomologist who specialises in beetles), and he confirmed their identity – a result that was very satisfying for me, as it meant I’d successfully recognised another stage in the life cycle of this species.

I turned my attention then to the falls themselves, and to the rock formations through which the water cascades. It was some time since I’d been right to the edge of the falls, but in the moment it was exactly where I wanted to be, and as it turned out, I spent the rest of the day there.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

It’s actually very difficult to see the falls themselves, because of the angle at which the river plunges down between the rocks. The best view would be from the bottom of the gorge itself, immediately below the falls, but it’s impossible to get there – that would require being lowered down on a rope, and hanging in mid-air. The best I could do was take some photographs looking down into the gorge, which only provides a partial view of the falling water.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

After some time looking at the water plunging into the depths of the gorge, I moved just upstream of the falls, to enjoy the view from a different angle. Although Dog Falls is one of the most popular visitor attractions in Glen Affric, very few people seemed to be stopping there this day, so I had the area to myself for most of the time.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I had a literal field day with my camera, taking all these photographs, and many more, in the region of the falls themselves. It was very good for me to do this, for although I’ve visited the falls countless times over the past three decades, I’d never before spent so much dedicated time with them. I felt like I really got to know the falls this day, in a way that I hadn’t before, and I hope that these images convey something of that experience. I also shot some video, which gives a different impression of the falls, so I’ll finish with that here:

 

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