A couple of weeks ago, a snowy owl in the care of Atlantic Veterinary College staff was released back into the wild after recovering from severe emaciation.
It was an event Dave McRuer says is uncommon — usually, by the time snowy owls are found in this condition, he said it is too late to save them.
McRuer is a wildlife health specialist with Parks Canada based at the Atlantic Veterinary College in Charlottetown. His job takes him to national parks across Canada, where he has periodically come in contact with snowy owls. He was also director of wildlife services for 11 years at the Wildlife Centre of Virginia, where they would occasionally receive snowy owls, and worked with them as intern at the University of Saskatchewan.
Since snowy owls are in the news, we asked McRuer to share what he finds most interesting about the rarely seen species, and he generously obliged.
1. Why they’re suddenly here
Snowy owls breed and usually stay in the North, on the flat, frozen tundra territories of Canada, the U.S., Greenland and Russia.
Some, however, migrate even further north to pack ice where they forage on polar bear kills, and to open water there where they feed on sea ducks.
Still others will migrate as far south as the Carolinas and do so annually.
Every five years or so there’s what scientists call an irruption, when large numbers of them migrate south. Rarely — once every few decades or so — there’s a “super movement” of snowy owls south.
Right now, snowy owls are in an irruption year, which is why more are being spotted in southern locales including P.E.I. These periodic moves south were thought to be because of a lack of food, but scientists have now debunked that theory and are working to discover why, McRuer said. For more on the owls’ migration, he suggests checking out the Project Snowstorm website.
2. ‘Young and dumb’
The snowy owls that show up here in Canada are typically younger, McRuer said.
Scientists affectionately call them “the young and dumb” because they haven’t had as much practice catching food.
If they miss a few attempts in a row, they can become weak, which can lead to a “downhill spiral” ending in starvation and death, McRuer said.
“Those are typically the birds that don’t move at all when you walk up to them here,” he said. They can end up at the AVC and other wildlife rehabilitation centres, and usually die because they are too severely emaciated.
“It’s pretty rare that they make it through,” he said. “There’s no muscle left on their bodies whatsoever.”
3. Females are bigger
Like most raptors, the females of the species are bigger by up to one third.
The males are almost pure white, McRuer said. The females have some black marking or “barring” across their chests, wings and heads, and the young snowy owls have even more barring.
4. That’s a lot of eggs
Normally the females each lay five to seven eggs a year, but in years where food is very plentiful, they will lay 12 to 16 eggs in one nest.
“Those years, there is a ton of snowy owls, and when winter comes, there are territories that these owls do have, and there’s just not as much room for all of these young owls, so they tend to migrate south,” McRuer said.
Those are the years people report seeing more snowy owls.
5. 1,000-yard stare
Snowy owls can see for up to a kilometre — really well. As in, a mouse half a kilometre away scurrying across the snow. That’s lunch!
“As soon as they see it they’re off, and they can actually fly really quickly” in pursuit of food, McRuer said, even though at four to five kilograms they are the heaviest North American owls.
6. People make them nervous
Because they can see so far away, they can of course see you coming, and they don’t like people getting too close.
McRuer said if they are fidgeting and staring directly at you, you’re too close. The best way to observe them, he said, is with binoculars, from your car.
“Cars are fantastic blinds,” he said. “You can generally get closer to any kind of wildlife in a car than you can just generally walking.”
If you “bump” the owl, or get so close it flies away, that’s a bad thing, McRuer said: It makes them more vulnerable to predation, and it uses up valuable energy they need to hunt and survive. It also stresses their immune system.
7. Mmm, tundra grouse
Prey consists of small rodents like lemmings and voles, and the occasional ptarmigan, a small tundra grouse.
And, because they are used to hunting in 24-hour darkness in the North, they usually hunt at night.
“Never feed owls,” McRuer said, even if they look hungry. “It just encourages the owls to come close to cars,” and they are often hit by vehicles.
8. Watch out for that eagle
Snowy owls are listed as a vulnerable species and therefore hunting is forbidden. There are 100,000 to 400,000 around the world, he said.
But other animals don’t know that. Arctic foxes eat the owls’ chicks and eggs, but McRuer said adult owls can take on a small Arctic fox (about the size of a domestic cat) and win. Arctic wolves and polar bears will also scavenge on the nests if they find them, he said.
People hunted them and stuffed them for show in large numbers in the late 1800s and early 1900s, McRuer said.
In southern climes such as P.E.I., their main predators are red-tailed hawks and eagles.
But mostly they die due to human activities, McRuer said, such as collisions with vehicles or utility wires, eating rodents that have been poisoned, or being snared accidentally by hunters.
9. Where to spot them
The owls’ habitat in the Arctic tundra is flat, so they’re most at home along the shoreline or perching on a sand dune or telephone pole, but not in trees, McRuer said.
10. Life span
Wild snowy owls, like most raptor species, can live as long as 15 years but generally most die “pretty quickly,” McRuer said.
That’s why they attempt to have and care for as many chicks as possible.
Snowy owls can live close to 30 years in captivity, McRuer said.
11. The myth of the wise owl
McRuer is also a falconer, and trains raptors such as hawks, falcons and even some species of owls.
“I can tell you owls are not as easily trained as other raptors. They just don’t pick up on things as quickly,” he said. “I’m not going to say they’re dumb, but they’re a little slow on the pickup.”
The birds he has trained are ones rescued at rehabilitation centres and are used for educational purposes, he said. However, he has not trained a snowy owl.
“Having a bird on your glove, you get a lot more attention than just sort of standing up there with a power-point presentation,” he said. “They make great education ambassadors.”
McRuer does not encourage people to try to keep them as pets.
12. They can breed with other owls
Scientists have seen snowy owls breeding with other large owl species — so far only in captivity, McRuer said.
But don’t be surprised if climate change brings about a hybrid in the wild soon, he said.
“That’s occurred in other Arctic species like polar bears and grizzly bears, for example,” he said.