Saturday, 30 May 2015

Confident Ptarmigan

A hen ptarmigan sits on her nest, quite relaxed - confident but watchful

I have been surveying rock ptarmigan on the hilltops in the far north-west of the Scottish Highlands over the past few weeks and they are now incubating their eggs. The eggs will take about three weeks to hatch, so the birds have to select their nest sites carefully if they are to gain shelter from the type of wild wind and rain they have had to endure recently.

I found this hen ptarmigan soon after finding her mate, who was about a hundred metres uphill watching over her. As I approached him, he flew off then landed about two hundred metres away, giving a brief croaking alarm to the hen. I knew by his behaviour that he would have a hen on a nest somewhere nearby. Although there was a seemingly endless choice of places where she could have been hiding, with years of experience, I took a look over the area and checked what I considered the most likely place where she might be. It helps to think like a ptarmigan and reason why a bird would choose what features to nest near. And there she was, quietly sitting on her nest as I approached, relying on her camouflage to conceal her in the the short vegetation, which was only about seven centimetres tall.

She was nesting in the short Arctic-alpine heath on the summit plateau of a hill

Unlike red grouse, a closely related species which hide and nest in or under the taller heather on the lower moorland, ptarmigan live successfully on the short Arctic-alpine heath which is seldom tall enough for them to hide beneath. They rely heavily on boulders or exposed bedrock for shelter and concealment. Their plumage colouring matches both the heath plants and the lichen-covered rock. Rock ptarmigan are never far from rock of some kind, hence their name.

She had placed her nest close into the lee of a large boulder

I hadn't taken my main camera or lenses with me that day as I had to walk over twenty kilometres of wet heath and bog, climb the hill, and walk into a strong wind. So I only took the binoculars and telescope, and my mobile phone, which was all I had to photograph the ptarmigan with. No problem though, as I always talk to any ptarmigan I approach, for what predator talks to their prey before pouncing on them? I sat down slowly and gently a few metres from her and began to chat. Initially, she had been holding her head low and I could see her breathing deeply. Then, after a minute or so, she had accepted me, lifted her head and began breathing more slowly. I inched towards her and took a few shots, explaining what I was doing all the time and telling her how much I appreciated her life on the high tops. I don't think she understood a word I said, but there was some form of understanding between us and I am sure that she was confident all the while that if I approached too close, she could jump off and fly away unharmed. If any animal uses camouflage for concealment, it needs to be confident in its effectiveness, and evolution needs to have honed the animal's cryptic colouring to perfection. I think this applied to that ptarmigan as a few hundred metres away there was a large cliff and half-way down that cliff there was a pair of golden eagles with a hungry chick. I left the ptarmigan and wished her luck.

From an eagle's eye-view,she was well concealed, as her cryptic plumage matched the colours of the heath

Sunday, 24 May 2015

Dryas octopetala and a crafty spider

Freshly opened flowers of Dryas octopetala on a cliff top 

There are outcrops of limestone in the Durness area of north-west Scotland and the resulting soil offers suitable growing habitat for base-loving plants such as the Mountain Aven Dryas octopetala. These Arctic-alpine plants seem to almost grow on the bare rock in places, the soil is so thin, and they can also grow on the sea-cliff tops where there is more than a little shell sand blown in by the Atlantic winds. In places, there are large creeping carpets of the plant's glossy green leaves, and now the flowers are opening, showing their distinctive eight petals from which they are named. Although not all the flowers have eight petals.

As their name suggests, eight petals are the norm

I was creeping about on a rock face, balancing the camera as I tried to photograph the flowers and the plants in their habitat, when I noticed a crab spider lying in wait on one of the flowers. Patiently waiting for an insect to land on the flower for a sip of nectar, when it would pounce and grab it.

A crab spider waits in ambush, forelegs held aloft ready to strike

These spiders don't spin webs, they rely on ambush to catch their meal. The front two pairs of legs of a crab spider are adapted to catch their prey, and they are held up high and open while the spider waits. While it waits, the spider lies facing the centre of the flower, ever ready to jump at an insect as it lands on the nectar-baring flower parts.

The two pairs of fore legs are for catching, the hind two pairs for standing, then jumping
However, after numerous attempts to find an on-line guide to what species I found, I am non the wiser. So, if anyone can help identify this spider please do add a comment below.

But - what is the species?

Thursday, 21 May 2015

Surfin' Gadwall

A pair of gadwall Anas strepera dabble in a stream outflow on the estuary

It has been a wild and windy Spring in the far north-west of Scotland, but the birds seem to be just getting on with life and take the weather as it comes. I couldn't venture into the hills the other day as it was too stormy, so I went along the shore of the Kyle of Durness to see what was about. There was a small flock of dunlin with a sanderling, ringed plovers and a few whimbrel, all waiting for the wind to change so they cold fly north to Iceland. And in amongst a flock of black-headed gulls bathing in the fresh water of a steam entering the sea water, there were a pair of gadwall. They were dabbling for food in the fresh water, as they normally do, but as the sea rose, they had to take to the sea and swim. That wasn't easy for them as the waves were rolling into  the bay. They had to paddle into the wave crests to reach calmer water beyond, then they drifted along to a bit of sheltered water behind some rocks. I hadn't seen a dabbling duck ride the surf before. Although I had watched red-breasted mergansers in big surf on a wide beach a few days previously and they, as expert diving ducks, simply dipped into the approaching waves and popped up behind them. Quite a contrast with the gadwall - they ought to stick to the fresh water.

The duck led the way into the waves

As they are dabbling ducks they didn't like to dip their heads into the waves, but kept their heads up like novice surfers

True to fashion, the water ran off their backs and off they went

Sunday, 17 May 2015

Frogs spawning in a mountain pool 

Common Frog Rana temporaria in a high hilltop spawning pool

It is now mid-May and frogs are spawning in the hill pools in the Highlands. Sadly, there have been many days of snow showers recently and there are lots of late lying snowbeds for the frogs to contend with.

Ben More Assynt from one of the frog pools on the summit ridge of Glas Bheinn
I was up on Glas Bheinn in Assynt yesterday surveying ptarmigan on the high rocky ground, and while walking past a small pool at about 700m I noticed some frogspawn in the margins. I counted about 75 separate clumps of spawn and some of the tadpoles had begun to hatch. Then I checked a second pool where there was still snow lying around the edge, and there was one massive accumulation of spawn in a corner. Some of it had been frosted and the embryos were dead. The spawn had a grey opaque appearance. Then I noticed that there were numerous dead frogs lying on the bottom of the pond, while others were still amplexed together and swimming in the near-freezing water.

Late-lying snow edged the pool and the grasses had not yet started to grow

Life for those frogs up on the high hills is so different from that of those in the warmer lowland waters. They must be so wonderfully well adapted to survive in such conditions. They are amphibians, cold blooded animals, yet they were getting on with life right on the margin of their physiological capabilities. Meanwhile, I was all wrapped up in windproof clothing and still felt cold in the northerly wind. Well done the frogs that managed to lay their eggs and their tadpoles that hatched. Well done.

A large clump of frogspawn lay in the shallows, and dead frogs lay in the depths

Wednesday, 13 May 2015

Sea-eagle and sandpiper

It has been a hectic week, or rather two weeks for me recently, trying to study greenshanks and golden eagles in the far north of the Scottish Highlands. All due to late snow showers and strong northerly winds. It's rather difficult to watch birds when I can't hold binoculars steady or even hold myself steady in buffeting winds. But, today turned out successful and I am back early enough to post an update.

The young white-tailed sea-eagle lifts off its feeding site leaving some morsels to a waiting raven

One evening last week, while out watching greenshank, I noticed a great black-backed gull standing on a hillside above a river. That seemed a bit out of place out on the moors, so I spied it, and immediately I saw why it was there. A white-tailed sea-eagle was a little downhill from the gull, feeding on something, I couldn't make out what. But I would not have noticed the eagle itself as it was an immature bird with no white on it. It's dark grey-brown body merged into the grey-brown hillside in the driving rain. I noticed the gull only because it was white on a dark background. I stopped and watched until the eagle had eaten enough and flew off. And as it did so, I grabbed a few poor long-range photographs through the rain, to check if it was ringed. And it was, but I couldn't make out the colours or numbers on the ring. It looks like it had been ringed as a nestling in 2014 by one of my colleagues in the Scottish Raptor Study Group, so I sent them a copy of the photograph in case they can make something of it.

Blue over yellow on the left, and dark green over metal on the right - the male of a pair a common sandpipers that have bred in the northern Highlands three times and been to Africa twice in that time, at least.

Then, on the next morning, on my way out to look for greenshanks, I saw a pair of common sandpipers feeding along a loch shore, so I stopped to check their legs for colour rings, and sure enough, both were ringed. These had been ringed by Ron Summers and Brian Etheridge of the Highland Ringing Group two years previous and when I told them about my sightings, they said the birds had not been there the day before, so the sandpipers had only just arrived back from their winter quarters in Africa that morning, or the night before. And there they were, looking as fresh as can be, having flown all those miles, not once but for their third time at least, back to their breeding grounds by a Highland loch. Wonderful birds.

Sunday, 3 May 2015

Spring snow and cuckoos

Snow covering the eastern Highlands - a view from above the North Sea

I flew into Scotland on Monday, the day after a snow storm and the hills were white with Spring snow. However, the weather continued to be wild and windy so it was few days before I could have a clear day on the hills. When I did reach the high ground I could see that the winter had been windy as there were lots of long-lying snowbeds, filled with drifted winter snow; on top and between there was a thin covering of soft new snow, lower down the ground was pie-bald with fresh patches. The whole landscape sparkled in the Spring light between the continuing showers.

The snowy ridge of Creag Leacach under a heavy sky

It was the 1st of May, and after the previous run of warm weather I expected the plants and animals to be well on in their fresh growth and breeding behaviour, no so. The buds on the heather and other heath plants had only just begun to expand, none had opened yet, and the hen red grouse were still feeding up to make their eggs, none had laid a full clutch and begun incubation. The cock grouse were calling out to mark their territories, with an occasional squabble between neighbours, but mostly they were walking along behind their hens, overseeing their safety from predators and keeping suitors away.

A male rock ptarmigan sits quietly - tricky to see as his pie-bald plumage merges well with the patchy snow lie 

My main purpose for the day was to count the numbers of pairs of red grouse and rock ptarmigan on a hill where I have been studying them for over twenty years. So after watching over the ground for a couple of hours, mapping the birds' locations, I ventured on up and slowly quartered the study area. The grouse numbers were high, but there were only a few pairs of ptarmigan and they were rather difficult to see in the snow.

He watches over his female as she feeds on fresh spring growth farther down the slope

As the day drew on, the temperature up on the hill began to drop, so when I came down I enjoyed the warmth of the glen. The birches were opening their leaves and when I stopped by a loch for a look around, I heard my first cuckoo of the year. A cuckoo and Spring snow, a nice day, and rather a nice start to my summer season in the Highlands.