Sunday, February 1, 2015

It's an ill wind, etc., etc.

Bad weather sometimes brings unusual birds into our small suburban garden, but this moorhen that arrived the morning was a real surprise. We are a mile from anything that could be described as moorhen habitat, with a lot of roads and housing in between, so it must have been flying over and just dropped in.




















First it had a mooch around the flower beds, then ....



...... failed to find anything interesting on the snow-covered lawn ....























.... so then it came right up to the house to pick up food that had fallen from the bird table. I hoped that it might fly up there so I could honestly boast that 'we had a moorhen on our bird table' - but no luck.




So then it just ambled down the garden path .....



.... leaving a distinctive set of arrow-shaped footprints in the snow, then ....






































.... paused to glance into the pond, which was covered with an inch of ice, before disappearing into the garden next door.


Saturday, January 31, 2015

Waders on a winter afternoon


Spent a very pleasant hour watching waders - sanderling, ringed plover and redshank - at Whitburn rocks near Sunderland yesterday. Nothing rare or unusual, just glorious sunshine, crystal-clear air, and the sounds of the surf and the waders' calls. 

The seaside in winter is a great place to be on days like that.




















Sunday, January 25, 2015

Honeybees in January


Two days ago we had snow on the ground and freezing winds. Then the thaw arrived.






































Today, at mid-day, it was like spring, with warm sunshine coaxing out honeybees in our son's back garden at Winlaton Mill near Gateshead.























The bees were busy collecting pollen from Viburnum tinus. There as also a bumblebee out, but it flew away over the fence before I could see what species it was of take a photograph.






































This one had full pollen baskets

More on winter honeybees here


Thursday, January 22, 2015

Newly-hatched lacewing larva

I found this amongst some old colour transparencies that I took about 20 years ago. It shows a newly hatched lacewing larva, climbing out of its long-stalked egg that's attached to a hawthorn leaf.






































For some more images of a predatory lacewing larva, carrying the corpses of its victims on the bristles on its back, click here


Wednesday, January 21, 2015

A moss with teeth


These are the ripe spore capsules of cypress-leaved plait moss Hypnum cupressiforme - a moss with teeth.


Many mosses have teeth - peristome teeth - that surround the mouth of the capsule and regulate the dispersal of the spores. They're highly sensitive to changes in atmospheric humidity, so in dry air they curl back and allow the spores to be shaken out, just a few at a time, when the capsule vibrates on its stalk.

























It's fascinating to watch the teeth uncurl and then curl under the microscope when you breath on them. They seem to be alive, although they're really formed from dead cell walls that react to changes in atmospheric moisture in the same way as the scales of a pine cone.


Monday, January 19, 2015

Snakefly


Back in 1974, when I worked in a research station at Wellesbourne in Warwickshire, I used to take a regular lunchtime walk along the footpath across the farm. One day I spotted this extraordinary insect - a snakefly Raphidia notata - on a cow parsley umbel. 

In those days I had a very basic camera and could only afford black and white film, but I managed to take some photographs. Yesterday I found the negatives (that I'd never printed) 40 years after I took them.

This is the only time I've ever found this rather uncommon insect. I've been looking for another for 40 years, with no luck, but still hope that one might wander into my field of view, so that I can photograph it in colour with better equipment.



Snakeflies belong to the insect order Neuroptera, which also includes alder flies and lacewing flies, and their distinctive feature is that extraordinary elongated neck.


This specimen was a female. That long, curved ovipositor is used for laying eggs in the bark crevices of oak trees.


Snakeflies are predators, feeding on other, smaller insects. I was able to watch this one hunting aphids in a cow parsley umbel.











That long neck is useful for reaching forward through narrow gaps to reach prey, like .....


... this aphid that it has impaled in its jaws.






































Click here for more information about snake flies

Thursday, January 15, 2015

A Golden Wall

Thursday's Guardian Country Diary is about this remarkable 'golden' wall at Hexham, in Northumberland's Tyne valley. It's a retaining wall beside the main Carlisle to Newcastle railway line, that crosses the Tyne just beyond that bridge in the distance and passes this point at head height.







The golden covering is caused by an alga called Trentepohlia aurea.


It spends the drier months of the year as a  powdery deposit on rocks and tree trunks but when it's wet the alga grows into a forest of minute filaments, forming a dense mat on the surface.
























You can see the filaments in this close-up, grouped together to form golden cushions that are a few millimetres in diameter. This wall is constantly wet, due to water percolating through from the railway track bed, so conditions are near-perfect for the growth of the alga.





















When the tufts coalesce into a golden carpet they provides a very striking back-drop for other plants that are colonising the wall, like this ivy and .....



The liverwort Conocephalum conicum, also known as snakewort. Its surface is divided into small polygons, each with an air pore at its centre, giving it a resemblance to green snakes' skin.


There are other liverworts on the wetter sections of the wall, including this one which I think is Pellia endiviifolia.





















The crevices are home to mosses and this little fern with leathery fronds - wall rue Asplenium ruta-muraria.



















The alga seems to thrive particularly well on the cement but there are patches of lichen on some of the stones. A close look at this one revealed ....









































.... these fungal fruiting bodies, which look like tiny pink toadstools. I think this is a species in the genus Baeomyces.

























Another lichen, this time .....






































... with fruiting bodies (apothecia)  that look like minute disks of liquorice. A species of Lecidea?






































This lichen is a Cladonia species, probably C. fimbriata

Lichens are formed by the symbiotic association between a fungus and an alga and it's very likely that the algal symbiont of some of the lichens on this wall is Trentepohlia






































Back now for a closer look at the alga Trentepohlia, this time under the microscope.






































Under low magnification (c. x40) with a stereo-microscope you can see the forest of algal filaments that make up those orange cushions, while ....



....... here, under a compound microscope (x100) you can see the cells that make up the filaments, and .....







































.... at a higher magnification still (c. x400) you can see the granular, pigmented contents of the cells.

There are animals living in the crevices in this wall, including the fearsome snake-back spider - but that's another story.