Monday, 4 January 2016
Tom Langlands - The Wonderful Whooper Swans of Iceland
Every year some 25,000 whooper swans fly from Iceland to overwinter in the UK. Although Iceland can get very cold in winter it is also one of the most volcanic places on the planet. Consequently, warm volcanic springs in some parts of the island mean that not all whooper swans have to migrate to escape the cold. Around 2,000 birds will remain in the warmer parts of Iceland all year round. Their natural habitat is a wetland one. Nests are constructed near to good clean water sources that provide the main food source of aquatic vegetation. Whooper swans live in family colonies and larger groups, becoming territorial mainly during the breeding season. Interestingly, not all adult whooper swans breed and only a small percentage account for the perpetuation of the species. Three or four cygnets is the norm with occasional broods of five or six. Generally birds will pair for life and whilst 'divorce' is uncommon it does occur occasionally.
Around mid October as the winter chill spreads south from the North Pole the whooper swans prepare to head to warmer climes. Some of these family groups will have youngsters that are only a couple of months old. Calm, moonlit nights are a favourite for the migratory flights. Birds will gather and characteristic whooping and head bobbing signals their intention to fly. Running on land or water to gain speed they stretch those huge white wings and lift off. They don't fly particularly high in the sky and tend to stay close to the surface of the sea. With almost silent wing-beats and only the occasional whoop cutting through the silence of the night they make their way to the Scottish coastline. It is a perilous journey and not all of the birds will make it. Some will become separated from their family groups and others may perish in bad weather having been blown miles off course. This is not a journey of choice but of necessity and survival. If all goes well many birds will rest on the Isle of Lewis before heading further south.
Some 500 Whooper Swans come to the Solway area near to Caerlaverock. It is always exciting to see parents arriving with new offspring, for the same birds tend to return each year. However it is a sad occasion when a bird known to have left Iceland remains unaccounted for. Once here, whooper swans are sometimes seen alongside our resident Mute Swans but, with their distinctive yellow and black bills emitting frequent ‘whooping’ noises, they are easy to distinguish.
Each winter at the Wildfowl and Wetland Trust reserve at Caerlaverock they catch many of the whooper swans to enable them to further their research and understanding of these birds. The swans are weighed, measured, have blood samples taken to check for viruses and toxins, and ringed.
With international law now protecting whooper swans it would be reasonable to assume that the birds should reach their normal lifespan of 10 – 12 years without facing significant danger. Sadly, this is not the case; lead shot is still a major problem. Although banned in the UK it is permitted in Iceland. Shot from spent gun cartridges or fishing is swallowed by the birds and just 3 pellets will cause a prolonged and painful death.Despite international protection a staggering 14% of whooper swans have lead pellets embedded in their bodies as a consequence of being shot. However, despite all of the hazards the swan population is actually healthy and growing steadily to the extent that that the Wildfowl and Wetland Trust no longer regard whooper swans to be a conservation concern.
Long may the current optimism continue for these wonderfully vocal birds are part of the Solway scene and somehow winter would never be the same without them.