New Scientist 31 January 2013 by Fred Pearce
Magazine issue 2902. newscientist.com
What creates the wind? Anyone will tell you that temperature differences are key. Hot air rises and is replaced by cooler air surging in beneath. Except that maybe the explanation found in every textbook is too simple.
What if, instead, the winds that drive atmospheric circulation are mainly created by the condensation of moisture? Much of this occurs over rainforests as water evaporates or is transpired from the trees. The physicists and foresters behind this controversial idea say that if we chop down the forests, we will lose the winds – and the rains they bring with them.
Saturday afternoon and we moved on from Westhay to the RSPB reserve at Ham Wall. Much standing around in the cold – the sun had gone in – and apart from a couple of Snipe hidding in the reeds and the obligitary Coots nothing much stirred. We could hear dozens of wildfowl out in the reed beds getting on with life, but not one was willing to put in an appearance. Breakfast seemed a long time ago and so we headed for the wonderful Eco Friendly Cafe at the Avalon Marshes Centre at Mere. Proper china mugs and they leave the tea bag in! Fortified by strong tea and toasted cheese and onion sarnies we sat back to reflect on the day so far and decide what to do next. At which point the Nuthatch arrived on a feeder behind us. I have never, ever, been that close to one of these striking birds and so took the opportunity to take its photograph, and then it was gone!
A few minutes later this adult Starling in winter plumage arrived looking like a pearly king (or queen, both sexes are very similar). Its legs and feet are already changing colour from winter brown to spring pink. Handsome bird.
If you are ever in the area and in need of refreshments, you could do a lot worse than visit the Eco Friendly Cafe.
Snow gone, not raining and the sun is out. Stuff the housework, time to spend the weekend on the nature reserves!
Saturday morning, we were sitting in a hide at Westhay staring at nothing in particular when we noticed something moving in the reeds near the hide. It was too dark to get a clear identification other than to note that it was small, shy and was not coming out. So when in doubt, shoot first and examine later.
That evening we sat down to process the days shots and were amazed to discover that the little bird bouncing around in the reed bed was a Cetti’s Warbler. Now whilst this is not a rare bird, (The population in the UK, whilst limited to southern England, East Anglia and Wales, has been gradualy growing since its arrival in 1961 from mainland Europe, where it breeds extensively from northern France to North Africa and east into Southern Asia.) it is very rarely sighted. This is a bird that has perfected the art of invisiblity. The RSPB Handbook describes it as ” a secretive and skulking species that would be overlooked if it were not for the outbursts of its distinctive song.” I think that is a little harsh. Ours was bouncing around in the reeds picking up insects quite happily – hardly skulking.
The Cetti’s (prounounced chetty) Warbler was named after the 18th century zoologist Francesco Cetti, an Italian Jesuit priest, zoologist and mathematician. Cetti took long excursions in the vicinity of Sassari in Sardinia, collating his discoveries in the Storia Naturale di Sardegna (Natural History of Sardinia) (1774–7). This has four volumes, covering quadrupeds, birds, fish, and insects and fossils respectively.
Oh yes, and whilst we were coming away from the hide, this busy little Blue Tit paused in its efforts to tear the reed stem apart to pose for my camera. There were bits of reed stem flying everywhere!
This is one of a pair who live in the woods behind our house. Our bird feeders hang in an old tree that is directly outside one of the kitchen windows, which is why we noticd him. We were sitting in the window with a mug of tea each watching the birds on the feeders when he turned up and started in on the fat pellets that we put down for the thrushes, robins and small mamals. He is very close to the house so the smell of humans and dogs must have been overpowering. He and his mate come through the garden early in the morning and at night but never in daylight before. There have been lots of rabbit tracks in the snow on the hill above the wood, so I’m surprised that he would take such a risk for such meagre pickings. Fortunatly the distance from the kitchen to my office and back is short so I just had time to grab the camera, run back ‘quietly’ and focus through the glass.
The fat dove sitting in the tree has distracted him and I suspect he may have been working out the odds…….
The following day the vixen arrived at about the same time, hoovered up some pellets and then left. We have not seen them since.
Here is Wikepedia on the origins of the name:
The Modern English word “fox” is Old English, and comes from the Proto-Germanic word fukh. It corresponds to the Proto-Indo-European word puk, meaning “tail of it”. The Sanskrit word puccha also means “tail”. The bushy tail is also the source of the word for fox in Welsh: llwynog, from llwyn, “bush, and grove”.
Another winter migrant from Scandinavia and Siberia, the Fieldfare have arrived in huge flocks. As the cuckoo is considered to be the herald of Spring, so the Fieldfare announce that winter is definitely here. An enormous flock descended on our garden, and the woods behind, two weeks ago when the snow was at its deepest. They quite literally filled the woods with their raucous chack-chacking. Fieldfares arrive on the east coast from October onwards and work their way across the country foraging for berries, resorting to worms and insects when the berries run out.
Fieldfares are large, colourful thrushes, much like a mistle thrush in terms of size, shape and behaviour. They stand very upright and move forward with purposeful hops. They are the most pugnacious of birds, prepared to get physical to defend a food supply. We put out apples and currants for them to supplement our meagre berry crop and watched as they strutted, argued, threatened and when that failed to deter a competitor, wrestled each other to the ground.
The English common name fieldfare dates back to at least the eleventh century. The Anglo-Saxon word ‘feldefare’ perhaps meant traveller through the fields. But it may be derived from Old English ‘fealu’ which in modern terms means ‘fallow journey/farer’. This may allude to the natural habitat of the bird being the fallow winter fields and their hedgerows. It is a lovely name, the ‘Fallow Farer’, and conjures an image of silent, frosty fields with the hedgerows laden with berries and flocks of ‘Fallow Farers’ busily flitting along them.
John Clare’s poem describes this scene perfectly.
On Emmonsail’s Heath in Winter
I love to see the old heath’s withered brake
Mingle its crimpled leaves with furze and ling,
While the old heron from the lonely lake
Starts slow and flaps its melancholy wing,
An oddling crow in idle motion swing
On the half-rotten ash-tree’s topmost twig,
Beside whose trunk the gypsy makes his bed.
Up flies the bouncing woodcock from the brig
Where a black quagmire quakes beneath the tread;
The fieldfares chatter in the whistling thorn
And for the haw round fields and closen rove,
And coy bumbarrels, twenty in a drove,
Flit down the hedgerows in the frozen plain
And hang on little twigs and start again.
I’m writing this today, Saturday, with snow still covering Somerset, trying to remember last Tuesday. It seems as if an entire season has passed and that last Tuesday happened sometime during a previous summer. If it hadn’t been for the low position of the sun, casting long mid-morning shadows, I could well have believed that I was experiencing one of those rare dry and even rarer, sunny, days of a summer past. I had decided to walk with the dogs across the fields towards Brean Down, a towering coastal peninsula that jutts out into the Bristol Channel and is almost the last uprising of the Mendip Hills before they disappear into the sea, and then north along the sands below Weston Super Mare.
At low tide here the shore line birds are usually far out across the mud flats and impossible to reach, but this morning, by luck rather than by judgement, the tide was still high over the sands, so that the few sea birds that had chosen this short strip of coastline to search for food were still close enough to approach on firm sand.
Distinctive amongst the usual assortment of crows and gulls was a small group of oystercatchers. These are distinctive birds with long red bills, red legs, mad red eyes and glossy black and white plumage. Despite its name oysters do not form a large part of its diet which is varied and dependent on habitat. Coastal oystercatchers prey upon limpets, mussels, gastropods, and chitons, whilst those on estuaries hunt for bivalves, gastropods and polychaete worms. Species occurring inland feed upon earthworms and insect larvae.
One noticable variation in sub-species is the shape of the bill which is determined by diet. Birds with broad bill tips open molluscs by prising them apart or hammering through the shell, whilst those with pointed bill tips tend to probe for worms. Juveniles watch and learn technique from their parents so a young individuals final bill shape will be defined by the habitat they grow up in.
As its name suggests, the redshank’s most distinctive features are its bright orange legs and slender orange bill that looks as if it has been dipped in black ink.
A member of the Sandpiper family, redshanks spend much of the winter on estuaries and coastal lagoons with as many as half of these birds having migrated from Iceland. Like the larger oystercatches these elegant little birds hunt for insects, earthworms, molluscs and crustaceans by probing their bills into the mud.
The problem with identifying gulls is that there are so many species and sub-species, all with subtle and often seasonal differences. So having taken some quite good identification shots and confident that my wife, an experienced bird watcher and fount of all knowledge, would be able to identify them for me I was a bit surprised when she said: “Dunno, gulls are difficult.”
So after several hours of intense study I believe that this is a lesser black-backed gull (Larus fuscus) and that this may be an adolescent; or an adult in winter plumage. You see the problem developing here? You know where you are with an oystercatcher or a redshank, but with gulls it’s all a bit vague.
This after extensive research I am fairly confident is a herring gull (Larus argentatus) or it could be another lesser black-backed gull……
This is a tricky one. The plumage suggests that this is a yellow legged gull (Larus michahellis), but with pale green legs and bill? Well if anyone reading this does know I would be gratefull if they would share their knowledge.
Sunday: further investigation, we got out all the bird books, reveals that this is probably a second winter common gull (Larus canus). Strangely, common gulls are not very common at all.
Later on Sunday: turns out that the herring gull is another lesser black-backed gull.
A group of these beautiful birds spent today feeding on mistletoe berries in an old cider orchard in Bathpool, just outside Taunton.
I had not seen a Waxwing before, so today was very exciting, particularly as the light was so good and there was the possibility of a good photograph. Waxwings in Somerset are, I think, a very rare event as the few that do make it across the North Sea are usually to be found along the east coast from East Anglia up to Scotland. For them to be this far west may well be due to the poor berry crop this winter. There normal diet when they are here is rowan, hawthorn, cotoneaster and rose. They may have been on the mistletoe because they couldn’t find anything more palatable.
According to the RSPB, birds that arrive in the UK are usually from Scandinavia and arctic Russia where they breed in spruce and pine trees of the Taiga. In winter, when their summer food of insects has gone, they rely on berries, and their winter distribution depends largely on the berry crops close to their breeding areas. In most years when local crops are good, they will move south and west, but not too far from the breeding areas, and only a small number will be seen in Britain. In poor berry years, large numbers of birds may move considerable distances and this is when we receive an influx in Britain.
It was so nice to be out in the sun again after so much rain.