26 December 2009

Unusual birds in our garden

Around Christmas we often seem to have some unusual bird visitors to our garden. In previous years we have seen Blackcap, Iceland gull and Reed bunting among others during the Christmas period. This year proved to be rewarding, no doubt partly due to the snow which has now been lying for a week.

On Christmas morning we had visits from a song thrush and a redpoll. Although we have had both species before, we hadn't seen either since the spring.

Song thrush

In the afternoon I went out into the park next to our house on my skis and spotted this treecreeper. Although this one wasn't in our garden, it wasn't far away. We have seen treecreepers here before, but not very often.

On the 26th we noticed a large thrush-like bird in one of the trees opposite. It made a brief visit to our garden to collect a cotoneaster berry. Viewed through the binoculars, it turned out to be a fieldfare, which is a new record for our garden. I tried to take a photo, but at that moment it took off so this is all I managed to get.

In the evening we were just going out for a night walk in the snow when we were astonished to see a pair of mallard ducks approaching our house. They seemed to recognise us when we appeared, and we can only think that they were a pair that visit us in summer and could find no open water in the cold weather. They were certainly very hungry. We have ducks visiting our garden every year, but only between late March and August.

Our complete list of species for Christmas week:
Black-headed gull
Carrion crow
Coal tit
Common gull
Great tit
House sparrow
Song thrush
Wood pigeon

12 December 2009

Conic Hill

Today was a very foggy day at home. I looked at the mountain weather forecast and it said that it would be a sunny day, but only above 300m as the fog would cover the lower ground. I had already thought of climbing Conic Hill, and at 358m, it seemed like a good choice.

The fog was thick all the way until I was close to my destination. Suddenly there was a break in the fog, and I could see Conic Hill in sunshine.

I soon climbed into the sunshine, but the fog then rose and hid the view until I was at almost exactly 300m. Suddenly it cleared again and the sun shone. I was soon on the summit ridge, and as the sun cleared I saw a glory - a ring of rainbow colours - on the cloud below me.

To the west, Loch Lomond was covered in cloud, though one of the islands was peeping through.

To the south, the Campsies were sticking up out of the fog.

The fog rose again and the glory became stronger, showing my shadow, the Brocken spectre, at the centre.

The mist was still swirling round the summit.

To the north, the fog cleared off the summit of Ben Lomond.

Soon it came rolling back up the glen below me.

I went to the west end of the ridge. Normally this is a good viewpoint for seeing the Highland Boundary Fault stretching across Loch Lomond, but this was blotted out by the fog which was rising and falling below me.

I stayed on the summit ridge for several hours, as I didn't want to go back down into the fog. Then I began the descent.

There was still some frost on the vegetation in places.

I had a last clear view back to the summit, with another Brocken spectre in the foreground.

I noticed that there was also a fogbow, which is just visible in the picture below.

Then it was time to go back down into the fog.

There are two slideshows of my previous visits to Conic Hill on the hill walking pages of our website.

For more information about glories, Brocken spectres and fogbows see the Atmospheric Optics site.

05 December 2009

Another ice spike

The season for ice spikes is here again. Yesterday morning one appeared in a plastic food tray which was nearly full of water and floating in one of the large trays of water we put out for the ducks. The spike was about an inch (25mm) high. This is what it looked like at 9am.

It was filled to the brim with water, and you can see that the water is bulging with surface tension slightly above the top of the spike. This is because the water in the tray freezes until only one point is left and, as water expands as it freezes, it gets pushed out of the hole and builds up a wall around it. As ice tends to freeze in a triangular pattern, these ice spikes tend to be triangular in cross-section.

Some time during the following hour, the water must have thawed enough to break the ice seal in the box. This caused the water level in the spike to drop. The following two pictures were taken at 10:30am.

I lifted the box out of the tray and held it up so the ice spike was against the sky. You can see that the top of each wall is curved upwards.

You can see several other entries about ice spikes in this blog, and we also have a section about ice spikes in our website.