Monday 25 July 2016

Clifftop lepidoptera

A pair of Six-spot Burnet Moths Zygaena filipendulae on the stem a red-campion flower
with the empty cocoon of the female below
I went out to the sea cliffs on one of those warm days last week, when it really felt like full summer with blue skies and sunshine. And the lepidoptera thought so too.

My initial reason for the trip was to spend a while watching the seabirds, so I headed out to some of the best viewpoints I know to see the kittiwake chicks which were quite large and would soon be fledging. Most of the guillemot chicks had left their ledges, but there were still some about as well as razorbills, shags and herring gulls. The fulmars were not long hatched so they will be on their nest ledges for months yet.

However, it was while walking between viewpoints that I noticed the flutter of activity along the cliff-top. There were butterflies and moths flitting all across the grassland and heath. The cliff-tops around the coast of Britain hold some of the least disturbed habitats in the country, for they are seldom grazed, and wild flowers thrive there. I shifted my attention.

The female on the left - her wings are still not fully unfolded after emerging


The most abundant species were Six-spotted Burnet Moths. The adult males had already emerged and were patrolling over the grasses and herbs for females. These were only just emerging that day, probably under the influence of the hot sunshine. The males detect them by scent and there were clusters of males in some places, swarming over single females as they emerged from their cocoons. Once one male had coupled with a female, the others seemed to accept they had lost their chance to mate with her and went away to seek another. One female had been found by a male before she had fully emerged and the two moths lay attached as she slowly pulled out of her cocoon and extended her wings.

A frenzy of males swarm over the source of a female's scent 


There was plenty bird's-foot trefoil about, so once their eggs were fertilised, the females would lay their eggs on the leaves of this favourite food plant of the caterpillars.

A male couples with a female before she has fully emerged from her cocoon


While the Burnet moths were colonial, the butterflies were mostly single, with males chasing away any intruders of their species, or even those of other species. While at the same time trying to attract and mate with any females that came through their territory.

The herb-rich clifftop grasslands


Meadow Brown butterflies were the most common in the grasses, because the caterpillars feed on various grasses. However, although there were lots of them about, whenever I tried to follow any to photograph, they would wander over a large area then dip into the sward, fold their wings and disappear in the strong shadows. It was easier to stay still, wait til they landed beside me and then take a photograph.

A male Meadow Brown Maniola jurtina  


The females were especially elusive, skulking in the tallest vegetation, safe from predators. Although there were few passerines about that would have taken them; mostly meadow and rock pipits and they prefer to hunt on short sward and generally eat small insects.

A female Meadow Brown



The male Common Blues were the most defensive of their territories and quickly chased off the large Browns as soon as they appeared on their patch.

A male common Blue Polyommatus icarus


The adult Blues were feeding on bird's-foot trefoil and clover, both of which are also food plants for their caterpillars. So all in all, the rich flora on the cliff-top with the abundant grasses, trefoil and clover was clearly a good habitat for the moths and butterflies.

Sea-cliffs are always great to visit for wildlife, but on that warm sunny day it was especially worth exploring. The seabirds were still on the cliffs, busy as ever, and the lepidoptera were busy on the tops. Let's hope these little sanctuaries never get destroyed,

A female Common Blue


Tuesday 19 July 2016

Honeysuckle Eyrie



The Golden Eagle breeding season is almost over, with most of the chicks fledging soon or having already left their nest. This one was jumping about and exploring its surroundings, taking very short flights between the nest and an adjacent ledge. It hadn't yet taken its first full flight a few days ago, but it might have done so by now as I write this.

This bird has been reared in one of my favourite eagle eyries, set below a deep overhang with a lush growth of honeysuckle which was in full bloom. How did the honeysuckle get there? Perhaps the eagles brought in sprigs to add to the eyrie and seeds came with them. The plant is certainly vigorous, probably a result of fertilisation from the droppings and prey remains in the eyrie.


This the first time I have seen a chick fledge from that nest since I first knew it in 1982. The birds have alternative nests on nearby cliffs and last year they raised a chick in one of those, which is very high and rather inaccessible. In the past, the birds' breeding efforts usually failed if they tried to nest on this relatively low and accessible crag. Disturbance was the most likely cause for their failure as they were usually successful if they nested on the big cliff. This territory is on ground once used for sheep rearing, and now that sheep numbers have been greatly reduced in that area and in the Highlands in general, there seems to be less disturbance.

There was a heavy mist when I checked the eyrie, some would call it rain, but the chick was well sheltered by the overhang. I was soaked through. The chick had a lovely big nest to play about in, and the view from the cliff is quite dramatic. What a wonderful eyrie to grow up in.



Monday 18 July 2016

Lots of insects - and birds

A Yellow Wagtail Motacilla flava eyes off a crane fly Tipulidae


As a final post on my recent trip to Norway, I would like to mention the insects, the profusion of insects which make it possible for so many migrant birds to breed in the tundra and birch forests. The most noticeable insects are the mosquitoes, of which there are thousands, millions, and all the females are intent on sucking blood. This is probably the most deterring factor for me to visit the arctic, but for the birds it is perhaps the most alluring factor. And many other insect species also thrive in high numbers, all adding up to form the rich feeding grounds for birds to rear their chicks. Of course, on balance, it is worth the discomfort to study the birds.

Mosquitoes torment a Short-eared Owl Asio flammeus chick


However, not all birds eat insects. The owls eat voles and have to endure the mosquitoes like we humans.

Male Red-spotted  Bluethroats Luscinia svecica are one of the more conspicuous birds in the birch forests
they often perch on on high perches when hunting for insects



The most obvious and abundant passerines feeding on the insects are the Yellow Wagtails, Red-spotted Bluethroats and Willow Warblers Phylloscopus trochilus. However, in some years the weather can be cold and insects scarce. Then the passerines are scarce too, as so often happens with bonanzas, it can be a case of boom or bust. The migrant birds clearly take a risk in flying so far north to breed, but the risk must be worth taking or else evolution would have selected against such behaviour.     

Female Red-spotted Bluethroats are one of the less conspicuous birds in the birch forest
when they hide on their nests 


The waders also rely on the insects. The adults eat them, often probing for the larvae, and the chicks eat them, often as adults, picking emerging mosquitoes as they lie on the water surface. If only they could eat a few more mosquitoes before they eat me. But now that I am back south and away from the mosquitoes, birch flies and horse flies, I have cast them out of my thoughts. I can now concentrate on the good memories; the wealth of flora and fauna in arctic Norway. That was a great trip.

Wood Sandpipers are very conspicuous when they have young.
They often stand on high perches overlooking the mires where their chicks are feeding
- even in the rain



Sunday 10 July 2016

Arctic Norway Flora

A northern Norway landscape showing a mix of  tundra with small pools and mires,
a large lake, birch forest and high mountains 



























While I was in northern Norway studying birds recently, I took the opportunity to note and familiarise myself with the plants. Below is a small selection of them; they are are all common in the area, some abundant and forming large proportions of the ground flora.  

Arctic Bramble Rubus arcticus


The Arctic Bramble was growing in small clumps, often only tens of centimetres tall and wide, very unlike its sprawling southern relation. I found it growing on hummocks in wet mires and on the forest floor, in sheltered, wet conditions. The flowers are delicate and like so many of northern species, short-lasting. I wondered how the fruit would taste, it is famed for its flavour.

Bog Bilberry Vaccinium uliginosum


Bog, or Northern Bilberry was one of the common ground covering plants on the hummocks in the mires. The drooping pink flowers would soon drop their petals and the dusty blue fruit would form. There are so many fruits on the tundra in autumn, forming a rich food source for the animals before the onset of winter.

Blue Heath Phyllodoce caerulea


Blue Heath is a very rare plant in Britain, confined to a few small locations in the Scottish Highlands. In northern Norway it is abundant, growing thickly on drier ridges and hummocks. It is one pant that seems to have taken advantage of the loss of lichens as mentioned in the previous post.

Alpine Bartsia Bartsia alpina


Alpine Bartsia is one my favourite alpine/arctic plants. The tubular sepals enclose the flowers, and the rich blue colouring flushes through all the uppers parts of the plant, making it difficult to make out where the flowers are in the crown. The downy surface on the leaves and flowers are a feature common on cold-climate species.

Wood Cranesbill Geranium sylvaticum


Wood Cranesbill is found widely in European and British woodland. In the far north, it grows in the birch forest and is commonly found on roadside banks. This is not a northern specialist plant, rather an example of one that has an extensive range. It is just as good to find old friends as to find new ones.

Blue sky and clouds reflected in open water surrounded by floating mire

























Saturday 25 June 2016

Lichen heath




The tundra in northern Norway covers a vast area and the landscape appears to be one large spread of rolling heath of browns and greens. From one horizon round to the other. The richness however, is in the detail, the fine structures and colours of the lichens which form some of the main ground cover. Hence, this post is simply a sample of shots to show the beauty of the lichens.



Most of the lichens are fruticose, those that grow in shrubby bush-type structural forms, and most are Cladonia species.I do not list them here, for that would detract from the visual appeal that I  have tried to portray, rather than a scientific list.



Bells of Blue Mountain Heath  Phyllodoce caerulea stretch up above the lichen sward.



When looked at in fine detail the lichens resemble the form and colours of a coral reef. And both are being destroyed by human influences. In the case of the lichens, they are being eaten and trampled by large herds of reindeer. There are hundreds of thousands of reindeer in northern Norway, herded by the indigenous Sami people. The lichens shown here are only a few centimetres tall, and in sparse clumps. In areas where there is less grazing by reindeer, they grow much more luxuriantly, often several centimetres tall. For more on this and some dramatic aerial images of the effect of reindeer, see this article in Arctic Biodiversity Trends.  I find it ironic that these lichens are often collectively referred to as reindeer lichens.



But for now, forget the ecological damage and political discussions, simply enjoy the colours and forms of the lichens as they are.

Wednesday 22 June 2016

Hawk Owls

An adult Hawk Owl Surnia ulula watches over its shoulder
There is an abundance of voles, Grey-sided Voles Myodes rufocanus in northern Norway this spring, so there are lots of raptors and owls breeding. Two species I have been seeing are Rough-legged Buzzards Buteo lagopus and Hawk Owls, both well-known specialist feeders on small rodents. The buzzards hunt mostly over the high open tundra and the owls in and around the woodland, but this family of owls were hunting around the edge of a small hamlet set in birch forest.


The owl brood were perched around this building; in the trees, scrub and wooden structures 
The adult female owl was perched high above her brood. She was up on wires, while her chicks were perched in birch scrub, one on the roof of a hut and one on the frame of a lavvu. These owls hunt by daylight, which in such a place above the arctic circle is no problem. There is abundant food and 24 hours of daylight to hunt. So the owls have large broods. There were four chicks at least in this brood, but there could have been perhaps seven or more.


An adult owl sits atop the frame of a lavvu, a Sami tent-type temporary dwelling
While the female was guarding the chicks, the male was away hunting, returning frequently with voles for the chicks. I have been seeing a few voles per day while walking through the local forests, but these owls were catching several per day, how many did they see per day. They are such efficient hunters, they probably saw many more than they caught, looking down from their high hunting perches.


A close up of the same bird
I have seen hawk owls before, mostly at a distance and in thick extensive forest, so it was a special experience to stand amongst them as they carried on their business regardless of my presence. And they really are such wonderful birds.

An adult bird brings a vole to feed a chick
Hawk owls can be aggressive in defense of their chicks, but fortunately these birds were not. They can attack humans around the head and draw blood with their very, very sharp talons. Another reason to admire them. And respect them.


One of the fledgling owl chicks
While watching them, I thought how easy it was to approach the chicks without causing them to fly away. Meanwhile, I stayed constantly aware that the adults were vigilant and could swoop at me if they wanted to. To them, I was easy to approach and cause to flee. And I would have done so if they had.

A wink that only owls can do so well

Saturday 18 June 2016

Grouse family

A hen Red Grouse and a chick up above, crouch low in the heather 












The Red Grouse Lagopus lagopus scotica, a race of the Willow Grouse, are quiet on the moors just now as they have chicks. They spend the day walking slowly through the heather and wet flushes of grasses and sedge. That is where the chicks, which feed themselves from hatch, can find more adult insects and caterpillars, important sources of nutrients for them in their first two weeks of life.

The hen watches me closely as I pass by


I was walking up a hill towards the higher ptarmigan habitat when I noticed this family hiding in the heather. They were spread over several square metres, crouched and frozen exactly where they were feeding when the adults must have given the alarm and they all crouched down to hide from, a potential predator - me.

The cock bird peeps through the cover of a sprig of blaeberry


I have studied grouse and ptarmigan for many years and recognised the behaviour of the adult male, whom I saw first. So I stopped in my tracks until I could see that my feet were clear of stepping on any chicks. Then I slowly crept round them, counting six chicks altogether.

The chicks are well camouflaged in the heather, blaeberry and moss


If I had stepped too close to any of the birds they would have jumped up and flown downhill away from me, cheeping if they were a chick and croaking if an adult. All would then have erupted from the heather in explosive flight. Each was crouched ready to jump at the first call. Even at only a week old, the chicks are strong enough to fly for about a hundred metres to safety. In such circumstances, the adults then quickly round them up once any threat of danger has passed. A great strategy to ensure that even if one chick were caught, the others should survive.

Crouching ready to spring at the first alarm call 



Friday 17 June 2016

Lesser Twayblade

A typical single plant of Lesser Twayblade, growing within a scattered group (out of shot)

On the long walk out from the eagle eyrie in the previous post, Adam Ritchie spotted a group of Lesser Twayblade Listera cordata plants growing right in the middle of the path we followed. These plants are not too uncommon on the wet peaty moorlands like the one we were on, but they are very easily overlooked and hence probably very under-recorded. Well done Adam for noticing them. Simon and I had already walked right over them.

The flower spikes were a pale pink/brown colour and faded into the background heather
they looked rather like dead stems of some other moorland plant

This was an added bonus to an already great day out, but the light was poor by then as it was evening, with clouds gathering for big rain on the ensuing days. Nevertheless, Simon and I pulled our cameras out of our rucksacks and grabbed a few shots.

The twin leaves growing at the base of the stem, opposite and enfolding one another - the distinctive leaf pattern of Twayblades 



These plants tend to grow in loose groups because they are more commonly spread by runners. If they are successfully pollinated, that is usually by fungus gnats. There were probably more plants growing in the moor beside the track as the habitat was similar, but these plants were perhaps as noticeable as they ever can be - growing in the middle strip of heather, blaeberry and moss between the ruts of the path.

Simon gets down low for a macro shot of the twayblade



Thursday 16 June 2016

Eagle nests are large

A typical Golden Eagle eyrie site in Scotland
set on a broad vegetated ledge behind an old Rowan tree 
The golden eagle Aquila chrysaetos chicks are now large enough to ring and I visited this nest a few days ago with Adam Ritchie, a fellow eagle researcher. Simon Cherriman, a friend and another eagle researcher - mostly of wedge-tailed eagles in Australia - helped and gained experience of how things are done in Scotland.

The chick is about 30 cm long and 20 cm broad, so this is a deep wide eyrie 


It was good that Simon came to this eyrie, for as the two of us roped down to the nest I was reminded of the size of these nests. I don't always appreciate that when alone. But with another person on the nest the scale became clear. The nest was huge.

Simon measures the length of the chick's head and bill
there is room for two people and the chick on the nest 


The chick was ringed and measured within minutes, a minimal intrusion when the adult birds are often away from the nest for hours when the chicks are this age or older - this chick was about four weeks old. Although I am sure the adult birds would have been watching us from a distance all the time.

The trailing edge on the foreground of the nest is the birds' landing platform, they don't flop down
 onto the nest but glide and stall onto the lower edge, then walk up onto the platform.
It also shows how easily the birds can launch themselves out onto the air straight from the eyrie
- there is a lot of space below

Saturday 11 June 2016

Misty Cotton


















There has been an east coast fog recently under the continuous cool north-east wind. In north east Scotland, this mist is known as the haar. In the evenings it creeps in over the land and one evening this week it was lying low on the moors. Meanwhile, it is the season for the cotton grass Eriophorum vaginatum to set seed, and this year there has been a splendid crop of the white cotton heads. The two features together make a soft delicate landscape. A transient tapestry.





































The individual plants of the cotton grass grow in tight tussocks on the wet moorland, bog really, known as mosses in the north-east. These cotton buds shine bright white in the sunshine, but in the diffuse evening light, the details of their silky tufts are the showpiece. Whether in close up detail or en masse.































When looked through from ground level,the sea of white rolled on and on, one snowflake after another, forming a fluffy bogland blanket.





























The hedgerows are full of white blossom at the moment, but the cotton grass even up-staged them. This was a truly spectacular sight, a soft but spectacular sight.