A CENSUS of the swan population took place this winter.
We have three species in Ireland but only the two migrant ones were counted this time around.
The survey was organised by BirdWatch Ireland, supported by the National Parks and Wildlife Service. The Wildfowl and Wetlands Trust covered Northern Ireland. Censuses are held every five years or so.
Swans have been around for a very a long time. The other waterfowl families, the geese and ducks, are thought to have evolved from them. Although they don’t appear in prehistoric cave art, these large white birds seem to have appealed to people in ancient times; ‘swan’, or a close variant of the name, is found in most European languages.
The word comes from Indo-European, from which most modern European languages and Sanskrit developed. According to the linguists, it denoted a non-musical sound, almost certainly the familiar ‘mewing’ of the mute swans’ wings in flight. The Latin ‘sonare’, meaning ‘to sound’, has the same root.
The children of Lir were turned into swans and spent 300 years on Lough Derravarra, 300 more on Inishglora, followed by a third exile on the Sea of Moyle.
The sudden appearance of migrant swans in the autumn and their equally inexplicable disappearance in spring may have given rise to the legend.
The birds’ shy and elusive behaviour made the creatures all the more mysterious; unlike their mute cousins, which fraternise with people and can become tame, the migrant swans shun human contact, preferring remote uninhabited locations. The difference in behaviour makes swan censuses interesting.
Which is the better strategy, shunning people or making a Good Friday Agreement of mutual respect with them? Tameness nowadays benefits mute swans but, in former times, things were not so rosy.
All mute swans in medieval England were captured as cygnets. In a process known as ‘pinioning’, a bone was removed from the wing rendering the bird flightless. Then mature cygnets were rounded up, fattened in pits, roasted and eaten.
The wilder Whoopers and Bewicks avoided such horrors. However, they were hunted vigorously everywhere and one species, the American Trumpeter, narrowly avoided extinction.
Migrant swans, paradoxically, are easier to count than mutes; they are not dispersed in pairs and family parties on lakes and along rivers but spend the winter in flocks.
Their haunts tend to be traditional; birds having been visiting some locations for centuries and swan counters know where to find them.
The census is a major logistical operation. More than 1,200 sites must be visited. Birds move frequently between locations so all locations have to be visited at or about the same time.
Given the limited manpower available, covering the entire country within 48 hours is a major achievement. There is still a risk that birds will be missed or counted twice but, hopefully, such errors cancel each other out.
The results of this winter’s census are still being analysed. In the 2005 survey, the number of whoopers counted was 14.079, 11% more than there were in 2000.
Almost 19% of these Icelandic birds were youngsters which had fledged during the previous summer. Families had, on average, 2.2 young.
Bewick swans, on the other hand, were thin on the ground in 2005; only 224 were counted, 17% of them juvenile. A century ago, Bewicks were more numerous than whoopers. Back in 1975-6, Oscar Merne of the National Parks and Wildlife Service, estimated that there were 2,000 of them in Ireland.
Several hundred visited the Wexford sloblands then, more than there are in the whole of Ireland nowadays. These small swans nest in Siberia, about 3,400km from here. Each autumn they fly to Denmark, northern Germany and on to the Netherlands. Some continue to Britain. Severe weather seems to determine how far they move. If conditions are mild and there’s easy access to food, few come to Ireland.
Conditions during most of the last decade have been mild, but this year’s census results promise to be especially interesting. The counts were made during one of the coldest spells since 1963. Will Bewick numbers be up?
According to national organiser Helen Boland, 150 counters headed into the field on January 16 and 17 and virtually all swan haunts were covered. Her analysis of the data collected is eagerly awaited.
a d v e r t i s e m e n t
This appeared in the printed version of the Irish Examiner Monday, March 15, 2010
