Snowy Owl (heavily barred) |
"An invasion of Arctic snowy owls is moving south in record numbers, many of them taking up residence in airports.
Driven by a search for
food, the birds are appearing in large numbers in central and eastern
Canada and the American northeast. Some are even behaving like
snowbirds, traveling as far as Florida.
“It’s an exceptional year,” said Kevin Kerr, curator of birds and invertebrates at the Toronto Zoo. “We’ve not seen numbers of owls like this down here in a long time.”
These predatory birds don’t typically travel farther south than the Great Lakes Region. But on ebird.org,
a site where birdwatchers, or so-called citizen scientists, post
observations, there have been sightings as far south as the Sunshine
State.
“This year’s invasion
is one of the most dramatic natural history spectacles in the northeast
and it is a story that continues to unfold,” according to the website
run by Cornell University, a world leader in bird research.
Media reports suggest
this could be a record year for sightings in Indiana and New Jersey, and
that eastern Ontario hasn’t seen these many owls in four decades. And
according to ebird.org, there’s an increase in numbers across all of
southern Ontario, compared with recent years. (In Toronto,
a good place to look for them, says Kerr, is Colonel Sam Smith Park and
Tommy Thompson Park, which is located on the Leslie Street Spit.)
Experts aren’t sure
what’s causing this “irruption,” a term used when birds migrate outside
their normal range. But there are likely two reasons, says Kerr. There
may have been a collapse in the Arctic lemming population — a favourite
food source — or a boom during the last breeding season that has
increased competition for food.
Snowy owls, which
start to return north in March, live in the Arctic tundra, north of the
tree line. When they migrate they look for broad expanses of flat and
treeless landscape that remind them of home, such as farm fields,
grasslands and rocky jetties.
A preferred stomping
ground in urban areas is airports, because of the wide-open areas
complete with grass, which are rich with small rodents. Not
surprisingly, airports, including Toronto Pearson International Airport,
are reporting higher than normal arrivals of the avian kind.
“We haven’t seen an
anything like this in 15 years,” said Phil Roberts, director of
operations at Windsor Airport. “They’re all over the place.”
Fifteen years ago,
staff caught close to 30 snowies. So far this season, they’ve captured
and relocated eight owls. Across the river in Detroit, airport officials
captured that many during Christmas week.
Because the snowy owl
is a “high strike-risk species” and easy to capture, many airports try
to relocate them, said Roberts, who’s on the steering committee of the Bird Strike Association of Canada.
“They’re a species
that we do have to be somewhat concerned about because they’re a very
heavy and large bird,” said Roberts. “The bird is big enough to cause
damage to an aircraft.”
The snowy
is the heaviest owl in North America, with females weighing an average
of 2.3 kg and males 1.8 kg. Their wingspan is between 125 and 145 cms.
Airports are already
experiencing strikes. Over the span of two weeks, in late November and
early December, five planes at JFK, Newark Liberty and LaGuardia
airports were struck by snowy owls.
Initially, wildlife specialists in New York were hunting the birds with a shotgun, but after that was reported, prompting public outrage, it was announced they would begin relocating the birds. (Officials at Pearson were not available for comment about their handling of the owl.)
Bird management at
airports is a big problem and not just limited to snowy owls, said Kerr,
who has researched bird collisions with airplanes. Each year there are
about 6,000 of these strikes in the U.S. and about 1,500 in Canada. The
issue has garnered greater attention after a passenger plane crashed
into the Hudson River in 2009 after hitting a flock of Canada geese.
Tanya Pulfer, a biologist with Ontario Nature,
encourages anyone who spots a snowy owl to report it to ebird.org
because it helps conservationists learn more about the species.
“We’re trying to help
mitigate the threats to the animal, and to really learn about why
they’re going, where they’re going and how far they’re willing to
travel.”
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