It’s spring, which means the arrival of something very special: baby animals! This past weekend, I saw some adorable Canada goose goslings. (And yes, it’s Canada goose, not Canadian!)
Canada geese (Branta canadensis) are large geese found throughout Canada, the United States, and Mexico. There are currently seven different subspecies, varying in size and coloration. The largest of them, the giant Canada goose (Branta canadensis maxima), is among the largest waterfowl in the world! Canada geese generally get smaller as you go north into Canada and tend to be darker in the western part of their range. Today, there are more than 5 million Canada geese across North America.
But we almost lost them in the early 1900s before environmentalists stepped in and enacted a successful wildlife recovery plan. Canada geese became legally protected and reintroduced into areas where they had disappeared. This protection plan was almost too effective: Canada geese today are still increasing in population, and many people consider them pests.
Goslings!
Even if you don’t like the adults, you probably agree that seeing goslings is one of the best parts of spring. But before Canada geese make goslings, they need to pick a mate. Canada geese practice what biologists call “assortative mating” – birds tend to pick mates of similar sizes. Larger males pair with larger females, and vice versa. These breeding pairs are stable, with Canada geese mating with their same partner year after year.
Once successfully paired, the female begins creating a nest. Canada geese like to nest near water and in a spot where they can easily watch for predators in all directions. The female makes most of the nest and finishes it with some down feathers plucked from her breast.
Goslings hatch after about 28 days and are basically ready to go. Canada geese are precocial, which means that the goslings hatch relatively mature: they can leave the nest when they are just one day old and are able to walk, swim, and even dive. Goslings typically remain near their parents, although sometimes they form larger “gang broods” with other nests. These gang broods are made of at least two nests and are watched by at least one adult. Goslings in a gang brood hang out together, moving and feeding as a large group of up to 100 individuals.
V-formation
Canada geese are generally migratory, moving south for the winter. However, migration patterns seem to be changing. Some populations travel less far than they used to and might only go a few kilometers from their breeding site. There are also “resident” Canada geese populations, which never migrate south for the winter. Migration patterns may be changing because of human activity (more waste grain available for eating in the fall and winter) and changes in the weather (warmer winters). Many of these residents are descendants of captive-raised giant Canada geese released to boost populations. These giant Canada geese didn’t traditionally migrate far, so their descendants don’t either.
However, when Canada geese migrate, they do so in a characteristic V-formation along established flight paths with “rest stops.” This flying formation is aerodynamic, and a flock of Canada geese can fly 1,500 miles in just 24 hours if the wind is good.
The V-formation also helps Canada geese maintain their energy during long flights. Each goose flies above the bird in front of them, which helps reduce wind resistance. This pattern also helps coordination by keeping birds in eyesight. When the lead bird gets tired, it moves to the back of the flock for a rest.
Poop machines
Canada geese are grassland birds. They like wide, open areas so that they can easily see potential predators approaching. This used to mean they liked living in fields. But as humans have expanded and started planting nice, open lawns, Canada geese have become increasingly common in urban and suburban areas.
During the spring and summer, Canada geese love yanking out and eating the grass on these lawns. Unfortunately, their rudimentary digestive system isn’t great at digesting grass, and food moves through their bodies quickly—in just two hours. So, they must eat a lot to get the nutrition they need and graze almost constantly.
And, of course, eating a lot and having a quick digestion results in a lot of poop. A Canada goose can create two pounds of excrement every day and may poop up to 15 times per hour. That’s a lot for a bird that’s only at most 20 pounds! For comparison’s sake, the average human produces only about 1 pound of poop a day. A flock of just 50 Canada geese can produce two and a half tons of poop over a year.
Unfortunately, poop is unsanitary and can harm humans. Their fecal matter can contain parasites and bacteria, which can easily enter the water sources Canada geese are living next to.
Aggression
But poop isn’t the only danger from Canada geese: they’re also incredibly aggressive and territorial. While they may spend the winter in larger flocks, Canada geese break off into their breeding pairs in the spring and start defending territories.
Canada geese are good at letting others know when to back off. When threatened, a goose may pump its head, open its beak, and hiss at the intruder. The protective goose may grab the intruder and hit it with its wings if it doesn’t get the message. This aggressive behavior can injure other birds and even humans who get too close.
Want to avoid getting beaten by a Canada goose? Watch them and their goslings from a distance, and if you hear honking, start moving in the opposite direction!
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