Flying on a wing... and a prayer

GEESE were in the news recently for all the wrong reasons; the airliner that came down in the Hudson River flew into a flock of them.

The culprits were Canada geese, huge numbers of which frequent the eastern seaboard of the United States in winter. A big gander can be half the size of a swan, tipping the scales at 5.5kg, not the sort of creature a pilot wants to encounter during a critical manoeuvre.

Gay Byrne later told RTÉ’s Mooney Show that jet engines were tested by having dead chickens flung into them. The turbine blades pulverise the carcass but can’t deal with birds as big as Canada geese.

Gay has a personal interest in this subject. In 1985, a plane in which he was travelling hit birds near Dublin Airport. An engine exploded and should have fallen off, in which case the plane could continue flying on the remaining engine. The shattered engine remained attached to the wing, dangling from electrical cables and pipes.

Boeing engineers believed that the drag from a hanging engine would cause the plane to fall from the sky, but, miraculously, the pilots managed to return to the airport and land. In the Hudson River case, both engines were put out of action.

Air travellers in Ireland may be at risk from bird strikes, but they have little to fear from Canada geese; there are not so many of them in this country.

This North American native is easily recognised by the white cravat which adorns its black neck. An enormously successful species, there are more Canadas in the world than any other type of goose. The “Canada honker”, as it’s known in the US, has a long association with people. Captive geese were brought to St James Park, in London, in 1665, to join the wildfowl collection of Charles II. Birds were then introduced to other estates in Britain. Waterfowl, kept in parks, have their wing feathers clipped, but a new set grows each year and birds escape to the wild. The Canada goose is a resourceful character; escapees are breeding wild in every country where the bird has been introduced. The British population remained at around 4,000 until the 1950s. Then, numbers began to increase. There were 61,000 Canadas in Britain by 1991. Sweden has more than 10,000 and there are estimated to be 30,000 in Germany. The number in New Zealand exceeds 40,000.

A few Canadas of the original wild stock cross the Atlantic to Ireland each autumn, and fraternise with white-fronted geese in places such as the Wexford slobs. There is more of a size variation within the 12 varieties of Canada goose than among the races of almost any other bird species.

The average length, from bill to tail, of specimens in the largest race is almost twice that of the smallest.

The smaller races are more migratory. Since the birds that come to Ireland are small, they must be American visitors. The large geese of the introduced British population are sedentary and don’t come here.

WE have, of course, our own introduced stock of Canadas. Olivia Crowe, in the book Ireland’s Wetlands and their Waterbirds, claims that the species was brought here in the early 1800s, but the growth in numbers has not been as dramatic as elsewhere. In 1980, there were about 538 Canadas at 23 Irish locations. A count carried out by BirdWatch Ireland, in 1997, gave a total of 975. Numbers are greatest around Strangford and in Counties Leitrim, Cavan and Fermanagh. Not everybody loves the Canada goose. It has become an agricultural pest in some places, feeding on valuable crops, trampling and soiling the ground. An aggressive bird, it bullies other waterfowl. Climate change has played into its hands; global warming is opening up previously inhospitable areas to colonisation.

The species is now breeding in East Greenland and there are fears that it might ethnically cleanse the white-fronted goose population if its numbers expand too much. American ornithologists seem to hate the bird. I once asked Bill Sladen, the New World swan expert, what should be done about the Canada goose. His reply was unequivocal: “we should eat it”.