Canada Geese are among the most identifiable birds on the prairies, but we tend to have a love-hate relationship with them. We love to see and hear them honking overhead on a quiet autumn evening–but we hate what they do to our parks, lawns and golf courses.
But if you think today’s geese are a nuisance, consider: last week Australian scientists reported the discovery of a prehistoric goose that weighed 500 kilograms. Before we get to the details, some background on the Canada goose of today.
There are several subspecies of Canada goose, characterized by variations in size and shading, ranging from the Giant Canada Goose (the kind we have in Wascana Park), which can have a wingspan of almost two metres and weigh more than 10 kilograms, down to the Cackling Canada goose, which weighs only a kilogram or two.
They all share certain characteristics, though: both males and females have similar coloring, pairs mate for life, they’re well-adapted for walking, they feed by grazing on vegetation, and they’re very social except when they’re nesting, when they establish their own territory and concentrate on raising their own young. Once those young are a bit larger, though, they and the goslings from other families are often joined together in large “crèches,” guarded by several parents at once. Natural predators include foxes, coyotes, wolves, bears, wolverines, gulls, eagles and ravens.
Like other waterfowl, geese are unable to fly for about a month in the middle of the summer, when they are growing new wing feathers. Once they can fly, they may migrate long distances (although the giant Canada goose, as we know, may not leave its nesting area at all if the winter is mild). Their family units stay intact during the migration; if you watch a flock come in for a landing, you can often see the different family units split off from the main group before they all alight.
One way to tell male and female Canada geese apart is their language: males make a slower, low-pitched “ahonk” sound, while females make a much quicker, higher-pitched “hink” sound.
Goslings have a soft, wheezy call at first; as they grow older, their voices may crack, so that they make a sound like a cross between the childish wheezy call and an adult honk.
It’s hard to believe today that at the end of the 19th century over-hunting threatened Canada Geese with extinction. The International Migratory Bird Treaty Act was created partially to protect them. Then, in the 1960s. small groups of the relatively rare Giant Canada Goose were discovered at a number of refuges, and attempts were made to rebuild their populations by capturing and moving the geese into new areas. The attempt was more than successful. In 1950, there were perhaps one million Canada Geese. Now the continental population, before hunting begins in September, probably exceeds 5 million. (The geese are even thriving in countries to which they’re not native: a 1991 census showed 63,581 Canada geese in the United Kingdom, where they were first introduced in 1665 as an addition to the waterfowl collection of King Charles II at St. James’ Park.)
With the burgeoning population have come new problems: too many urban geese. Geese like to graze on the short grass found on golf courses, lawns and parks, and as they graze, they defecate. Goose feces are an annoyance, though fortunately no evidence to date has suggested that they pose a human health risk.
But imagine geese that weigh, not 10 kilograms, but 500 kilograms, and stand as tall as an elephant. That’s what Australian scientists have unearthed in the central Australian desert near Alcoota, about 150 kilometers northeast of Alice Springs–not just the largest geese that ever lived, but the largest birds that ever lived, at least as far as we know.
The geese roamed the region from about 15 million years ago until just 30,000 years ago. They were probably vegetarian, but their beaks and jaws were very strong–strong enough, Peter Murray of the Museum of Central Australia in Alice Springs says, that they could shear your hand off with one nip.
That may have been a concern to humans, whose presence in Australia overlapped that of the giant geese by about 10,000 years. Humans, in fact, may have contributed to the extinction of the geese, either through hunting or through their use of large-scale fires to promote the growth of new, edible vegetation. (Australia lost a lot of giant animals at about that time, including a wombat the size of a hippopotamus.)
It’s doubtful they had many, if any, natural predators, Murray says. The giant geese were fast runners and had powerful legs. Attacked by, say, wild dogs? “No problems, they’d kick them into orbit.”
So today’s Canada Geese may be a bit of a problem, but at least they’re a manageable problem. The next time you step in something in the park, just remember–it could be worse.
