08 June 2013

Though Whooper Swans usually leave us in early spring, the extraordinary weather this year may have confused them. April was so warm they stayed for a while in disbelief. Then May came and was so cold they might just as well stay in Scotland as fly to Arctic breeding grounds.
They were still here in mid May but, though there have been occasional reports of breeding in the Outer Hebrides in recent years, the species appears not to have bred in substantial numbers in Britain since the late eighteenth century when there are records in Orkney (though in 1990 a pair of whooper swans bred on Loch an Daimh, by the road above Dunalastair water, and produced four cygnets).
Whooper Swans breed in the taiga from Siberia to Iceland using the same sites repeatedly for many years so that their nests grow to be large mounds of earth.  Individuals from Iceland and Scandinavia winter in Britain especially Scotland and in Ireland. They have been coming here for a long time. Whooper swans were hunted for food by Stone Age man and traces of the species have been found in Pictish middens in Orkney dating from the eighth century. alt
At the end of the 19th century their numbers were greater than those of the smaller Bewick’s swan, which I used to see wintering in Warwickshire, but this has now been reversed. In 1960 whoopers had an estimated population approaching 2000. This rose during the ‘70s & ‘80s to an estimated 9,000 for Britain but is now again in decline due to a change in the feeding habits of the birds who have turned to newly sown winter wheat, which still has toxic dressing on it and which has caused a number of fatalities.
Both whoopers and Bewicks have yellow patches between eye and bill. These patches are all differently shaped allowing identification of individual birds. It is said that Bewicks have the yellow are resembling a ’B’; the whoopers patch is a ‘W’.
Individual birds from the north winter in Britain, especially Scotland. Huge flights of Whooper Swans arrive in Ireland after an unbroken journey of 800 miles and, after resting, spread throughout Britain. In one year exceptional weather conditions produced an incredible migration; Whooper Swans travelling from Iceland to Ireland were tracked on radar flying at over 8000 metres, nearly the altitude of Everest, with a groundspeed of 86 mph . They appear to fly high deliberately to avoid the buffeting of turbulence at lower levels. This is all the more astonishing when one remembers that at such altitude the temperature may be as low as -50°C and oxygen tension extremely low. Birds have evolved a highly efficient respiratory system with the main air passages of their lungs communicating with air sacs in their bones reducing weight and allowing them to maximise the use of the reduced oxygen, even with these adaptations meeting the oxygen requirement of flight they must get short of puff at such a height.
Wintering birds congregate on large inland waters particularly in Perthshire. They are highly sociable out of the breeding season, when migrating parties form long lines, or sometimes Vs when flying high. Unlike the mute swan they are shy and tend to be seen at a distance. They are also less aggressive, failing to arch their wings over the back when angered as threatened mute swans will do. They roost in groups on large expanses of water and, when on land, walk more easily than mutes.
In Scotland’s  west coast there was the belief that these ‘wild swans’ cast the evil eye upon cattle making them give no milk. Swans were popularly supposed to be akin to angels, and to shoot one was to bring disaster on its executioner. Perhaps the eerie calls of these majestic birds contributed to these old beliefs. The typical call on the wing is a loud bugle-like hoot sounding more goose-like than the call of the Bewick Swan. It also produces a triple blast sounding like a motor horn, or a double whoop in which the second is of higher pitch. Before take off they often have a different call consisting of loud nasal bugle-like blasts
Look out for these beautiful swans on Loch Kinardochy in winter.

 

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