Sunday 27 May 2007

A warbler day, but a slug and beetle week

Monday was an absolutely brilliant day, a visit to a favourite village, lots of birds and warm sunshine. The rest of the week was a bit bogged down with survey work but lots of interesting things to see whilst doing it.


Aberlour was the village, right by the River Spey, surrounded by whisky distilleries and home to Walkers Biscuits. Fishermen were all along the river, and though I didn't see them catch anything it is always fascinating to sit and watch them flicking fishing line and fly way out over the water, only to retrieve it after about half a minute, and then start all over again. The village, which straddles the busy A95 is worth a visit and is also a great starting point for a walk along the Speyside Way ( red dots on map) to the next village of Craigellachie, returning on the opposite side of the river. Or, you can follow the Speyside Way in the opposite direction to Carron, again making your way back on the other side of the Spey. Conveniently, there is a suspension footbridge across the river by the car park in Aberlour, allowing the choice of two circular walks. This area gives a nice variety of birds and broadleaved woodland when compared to Nethybridge and Abernethy, and consequently a few more warblers are to be seen/heard on these walks. The warbler haul for the day was willow warbler, whitethroat, blackcap, garden warbler and sedge warbler and a total of 49 birds were seen or heard, though I always struggle with the difference between blackcap & garden warbler songs! I always like to produce as full a list of birds from an outing as possible for BTO Birdtrack recording, so I started off the walk by skirting the church graveyard, following the small stream back to the A95 (admiring the wee pack-horse bridge over the stream on the way) and walking back along the high street seeing lots of house sparrows and swifts, before turning left to get back to the river via the children's play-park. It was then a case of following the Speyside Way towards Craigellachie. The River Spey along this stretch is fairly wide and shallow allowing excellent opportunities for the salmon fisher-folk, many of whom wade well out into the river to fish the best rapids and slack water by the banks. The next good bird for the day was common tern, not one but two, dipping down to fish the river. With many shingle backs along the river there has to be a possibility that these birds could breed here. The Speyside Way actually follows the old Grantown- on-Spey to Elgin railway line and the old station buildings in Aberlour now provide office space for the Speyside Way rangers. From the path you get good views into the adjacent woodland where several pairs of starlings were feeding their young in natural holes in some of the older trees, and siskins, treecreepers and great spotted woodpeckers were also present. On reaching Craigellachie you leave the Speyside Way and enter the play-park to head towards the old road bridge over the Spey. This bridge is worthy of a visit in its own right, built as it was by Thomas Telford in 1814. Having crossed the bridge an old road takes you up to the B9102 which in turn takes you to the Macallan Distillery with its Visitor Centre where you might be able to taste a "dram" if you were to pop in before continuing your way back towards Aberlour! Check out their website at http://www.themacallan.com/ for more information. However, the best route to follow is the fisherman's track back down to the Spey just by the distillery entrance. A few yellowhammers were singing along this section of the walk, and both pied and grey wagtails were feeding young. Follow the river back to Aberlour and across the suspension bridge to get back to the car park. Brilliant.

It happened again this week, another violet ground beetle (Carabus violaceus) walking along a track with a wood ant attached to its leg! Why, I wonder, doesn't the beetle just turn round and grab the ant in its powerful jaws, and get rid of it? Is it actually quite terrified of this predatory ant? I found this a little odd when, later in the week I came across the same species of beetle killing a great big black slug. Certainly, if other ants followed the attached ants scent, the beetle would be in trouble (see left), but the beetle covered 15 metres in just a few minutes so it is unlikely that any ants would be following so quickly. But what about the beetle itself? Do you see these beetles around your garden? If so, do please leave them to carry on foraging because they are very beneficial to your garden. The violet (violent?) ground beetle is a member of the Carabidae family of which there are about 350 species in Britain. Many of this group of beetles are voracious predators and will attack and eat aphids, other pest insects and slugs and snails. By encouraging them to live in your garden you can use the beetles as a natural form of pest control. Unlike some other beetles, violet ground beetles can't fly, their wing cases (elytra) have become fused together, acting as protective armour. A few logs, leaf litter or the odd stone lying around the place will provide the shelter they require to hang around your patch. If you disturb the beetle however, it can discharge a noxious and highly irritant fluid from the tip of its abdomen, so just leave them to look after your garden. And the beetle with the slug about ten times its size? Well, having got its powerful jaws into the rear-end of the slug (see picture) it was able to release a fluid onto the slug from its jaws, disabling the slug and waiting for the digestive enzymes in the fluid to make the slug easier to eat. Eight hours later the pair were still together, the slug dead and the beetle with a large lump of food that it was going to stay close to until it had had its fill. Amazing.

Poor slug, but please don't be too hard on this big black slug (Arion ater), it is rarely as destructive as the three smaller species you often see around the garden and your veg patch. Put out a saucer with some beer in it if you don't believe me, and see which species fall in. Like all slugs it has a fairly powerful set of mouth parts, well able to rasp away at rotting vegetable matter, fungi, manure and even dead animals! At this time of year I also see very acrobatic black slugs, keen to feed on the abundant flush of broom flowers on the many bushes around the place. Way off the ground, the slugs seem quite confident as they "slide" out along the broom stems to get at the emerging flowers, though it only seems to be on damper days that you come across this balancing act. Have a look next time you are out and about on a damp day and see if you can witness this "death defying" act!

Joan and Robert, our chalet visitors last week wondered what the yellow dust was covering their car. In previous diary entries I have shown and mentioned the new growth appearing on the Scots pine trees. The male pollen bearing "flowers" are now fully grown and, as the wind starts to blow, the pollen is wafted around and some of it will land on the new pine cone flowers ensuring fertilisation and new cones developing next year. The new shoots and pollen flowers are mini works of art and worth looking at in close up, mostly they are completely yellow but occasionally you find vivid red ones, both produce the same fertilising yellow pollen. A still, warm spell of weather at this time of year can create perfect conditions for visitors to the area to think that the forest is on fire if suddenly a breeze develops and the pollen from the pine trees is lifted high into the air above the forest. The pollen looks just like a swirl of smoke as it wafts across the tree tops. Deposits of the same pollen into Loch Garten can similarly provoke genuine phone calls of worry to the local environmental health department reporting a serious pollution incident at the loch as a thick yellow sludge washes up in the loch shore! It really does look like someone has deposited a tin of yellow paint in the loch. I had a bit of fun trying to capture a pollen "event" at one of our trees in the forest, I think you should just about get an idea of just how much pollen must be blowing around when you see how much appears from just a small, low-lying branch, shown left without pollen and right as pollen appears.

There is also a lot of evidence locally of the Scots pine leader shoots of new growth being eaten by capercaillies (left). It would appear, that over the years, the same young trees are targeted by the birds and they then start to develop a very bushy appearance. I have no doubt that eventually the nibbling away at the new growth helps form some of our characteristic round-topped Caley pine trees in the forest. Instead of the trees growing tall and pointy, they develop a very rounded crown much loved by cone feeding crossbills. Browsing by red and roe deer on the leading shoots of young trees will also produce the same effect. The tree on the left is typical of what the foresters and sawmills require whilst the one on the right is typical of many of the trees of probably higher conservation value, within Abernethy. Elsewhere in the forest the first crested tit families are appearing much to the relief of visiting birdwatchers. An evening wander through some restored bog woodland produced a nice surprise. An alarming mallard alerted me to the possibility of a water-borne predator being about, and lo-and-behold a foraging otter popped out of the clumps of reeds! After poking its head into many of the reed clumps, it swam off down the dammed up drain. Phew! As with the rest of the UK the weather of late has been changeable to say the least. On 25th I was surrounded by huge numbers of large red damselflies one minute and pelted with hailstones the next, not the best weather for progressing the mason bee survey (Osmia uncinata) even though lots of bird's-foot trefoil is now starting to flower. This wee bee likes the temperature to be in the high teens, and only starts to forage once the sun shines fairly continuously throughout the day. Fingers-crossed for next week.

Happy reading & have a nice Bank Holiday

Stewart & Janet




Firwood drainpipe in action as seen & queried by chalet visitors!

All photos © Stewart Taylor