This kind of goose was once an endangered species, but now people have to give them family planning again.

Originally a migratory bird, the goose migrates back and forth between Canada and the United States every year, thanks to its huge size (wingspan 1.27 to 1.85 meters, weight 2.6 to 6.5 kilograms) and its natural aggressiveness, it has few natural enemies in adulthood, only hyenas, gray wolves, golden eagles, sea eagles, snow owls and so on. As a result, their original habitat is so vast that they can be seen from northern North America to areas close to Central America.

However, with the expansion of European colonists in America, especially excessive hunting and land development in the late 19th and early 20th centuries, the population of Canadian geese plummeted, and by the 1950s they were even thought to be extinct. In 1962, however, American researchers found a small herd of overwintering geese and launched a population recovery effort for Canadian geese.

In the process, because artificially bred Canadian geese are unable to learn migration skills from their parents, and there is still an adequate food supply in human cities in winter and few natural predators, these Canadian geese no longer migrate and become settlers in the city. The number of them in the city has increased so rapidly that it has quickly changed from a rare protected animal to a disgusting "pest".

Canadian geese have become urban settlers and can be seen in many North American cities. Figure / wikipedia-Pierre5018

Although they sometimes prey on small insects and fish, Canadian geese are generally herbivores, feeding on plant leaves, grains, legumes and so on. This habit will bring damage to local agriculture, especially the large-scale cultivation of wheat, corn, rice, soybeans and soybeans, which have become delicacies of Canadian geese. Of course, the major trash cans in the city are also fixed meals for geese. In this way, for food, Canadian geese not only bring losses to agriculture, but also wander the streets, bringing inconvenience to urban residents.

Canadian geese in the fields? Figure / Oregon Department of Fish & Wildlife

In addition, the feces excreted by Canadian geese have become a major source of pollution in those cities. Canadian geese are a kind of waterfowl, they like to be close to the water-in the city, all kinds of parks are their perfect habitat. And visitors to the park often feed, so that some geese can live well just by begging for food. In some urban parks in North America, hundreds of Canadian geese often gather to live together. However, they are veritable dung-making machines, and some foreign media have described that "their feces are bigger than their brains." A goose discharges 1.4 kilograms of feces every day. By simple calculation, two geese can discharge a ton of feces a year.

Foreign media are reporting that the streets of the city are full of goose dung. Look at the ground in this picture. Photo / screenshot of thestar.com web page

The problem is that the feces appear randomly in parks and city roads, and they may also carry large amounts of E. coli, which are mixed into lakes and coastal water, forcing many parks to restrict swimming in the summer. Even more irritating, the droppings left everywhere by geese attract the attention of dogs, and some geese build nests next to cisterns on the roofs of some buildings, which greatly increase the risk of human infection with E. coli.

A Canadian goose on a beach in a state park in New York. Figure / wikipedia-Geoffrey.landis

In addition, some geese cross roads or settle near airports, which also brings great risks to public transport. In 2009, American Airlines Flight 1549 was forced to land on the Hudson River because of a collision with a flock of Canadian geese, which was later adapted into the famous movie Captain Sally.

A live picture of Flight 1549 that crash-landed on the Hudson River? Figure / wikipedia-Greg L

As a result, major cities in North America have been trying to drive away Canadian geese since the 1980s. The easiest way to drive away is to use models of scarecrows or owls or crocodiles. Although people complain that Canadian geese have droppings larger than their brains, that doesn't mean they have bad brains. After a while, they get used to these methods, so this method quickly ends in failure.

Of course, the easier way to think of is to hunt Canadian geese, and many companies in the United States and Canada choose to do so, but this is greatly restricted. On the one hand, the law protects Canadian geese, and hunting requires permission to hunt. And can only be carried out at a specific time and within a specific scope. On the other hand, hunting will be greatly resisted, and the hunting habitat will still attract a large number of Canadian geese the following year, so this is not a good idea.

Demonstrators marched in front of the city government after Denver shot and killed 2000 Canadian geese in 2019. Photo / Denver Post website screenshot

In order to solve this problem, parks in the United States and Canada have come up with some comprehensive measures. The first is to transform the habitat to make city parks look like Canadian geese don't like. For example, reduce the lawn area, increase the density of shrubs or branches on the lawn (can limit the take-off of geese, they do not like this environment), and at the same time transform the urban suburban environment into an environment that geese like, attracting geese to the suburbs.

The second is driving. If the number of geese increases to a certain threshold, they will begin to drive. There are a variety of driving methods, such as laser driving, sheepdog driving, and drone driving. But some geese have learned their lesson, they will fly away at the time of driving, and then fly back soon! And if it happens to be in time for the breeding season, the Canadian goose leading the calf will have a bad temper, irritable and aggressive, and can easily break the head of both people and dogs.

The last way is to do family planning for geese! At first, the park rangers wanted to take the goose eggs directly from the goose nest, but the goose had the same habit as a chicken, and it would lay one or more eggs, so later people's technology was updated to take out the eggs, kill the eggs, and put them back. This method is simple and easy, poking the eggshell with a needle, or smearing the eggshell with grease (which insulates the air), or just shaking hard can prevent the egg from hatching. But the goose does not know, so it will continue to hatch these dead eggs.

Canadian goose nests are very common in some cities in North America. Figure / wikipedia-Famartin

But the disadvantage of these approaches is that they cannot be done once and for all and must be done year after year. We have brought them into danger of extinction, and now when their numbers are restored, we will begin to control their numbers, and there is still a long way to go to live in harmony between man and nature.