Page 28 - aruba-today-20171223

A28 SCIENCE
Saturday 23 december 2017

Snowy owls wintering in U.S. fitted with tiny tracking devices

By TAMMY WEBBER last North American mass — one step away from en- successfully, said Scott Wei- native villagers to help, it’s
Associated Press migration in winter 2013-14, dangered — by the Inter- densaul, director at Project mostly up to owls with trans-
CHICAGO (AP) — Scott already has yielded big sur- national Union for Conser- SNOWstorm, an owl-track- mitters for now.
Judd trained his camera prises. vation of Nature. They’re ing group whose volunteers Snowy owls somehow seem
lens on the white dot in the Instead of 300,000 snowy protected in the U.S. under have put transmitters on to find lemmings even if
distance. As he moved up owls worldwide, as long be- the Migratory Bird Act. more than 50 snowy owls in they are thousands of miles
the Lake Michigan shore- lieved, researchers say the This year’s mass migration the past four years . from where their population
line, the speck on a break- population likely is closer to is a bit of good news. Re- The snowy owl population last peaked, Therrien said.
water came into view and 30,000 or fewer. The previ- searchers once thought collapsed in Norway and “It’s amazing what we’ve
took his breath away: it ous estimate was based on these so-called “irruptions” Sweden in the mid-1990s, learned, but we need a
was a snowy owl, thou- how many might be able signaled a lack of prey in all but vanishing there for bigger database of birds,”
sands of miles from its Arc-
tic home.”It was an amaz-
ing sight,” said Judd, a
Chicago IT consultant. “It’s
almost like they’re from an-
other world. They captivate
people in a way that other
birds don’t.”
The large white raptors
have descended on the
Great Lakes region and
northeastern U.S. in huge
numbers in recent weeks,
hanging out at airports, in
farm fields, on light poles
and along beaches, to the
delight of bird lovers.
But for researchers, this win-
ter’s mass migration of the
owls from their breeding
grounds above the Arctic
Circle is serious business.
It’s a chance to trap and fit
some of the visitors with tiny
transmitters to help track
them around the globe
and study a long-misun- In this Dec. 14, 2017 photo, a snowy owl flies away after being released along the shore of Duxbury Beach in Duxbury, Mass.
Associated Press
derstood species whose
numbers likely are far fewer to breed in a given area. the Arctic, but now believe almost two decades be- said Smith, who has been
than previously thought, re- That calculation was made the opposite: Breeding owls fore reappearing at lower trapping owls at Boston’s
searchers say. assuming snowy owls act- feed on lemmings, a ro- numbers, experts said. In Logan International Airport
“There is still a lot that we ed like other birds, favoring dent that lives under Arctic Greenland, where the for more than 35 years and
don’t know about them ... fixed nesting and wintering snowpack and whose pop- population collapsed in fits them with a leg band or
but we aim to answer the sites. But researchers dis- ulation surges about every the late 1990s, researchers transmitter before letting
questions in the next few covered the owls are no- three or four years. More found a few nests in 2011 them go.
years,” said Canadian bi- mads, often nesting or win- lemmings means the owl and 2012 after six years with He put a satellite tracker
ologist Jean-Francois Ther- tering thousands of miles population explodes— and no recorded nests, but owls on an owl for the first time
rien, a senior researcher at from previous locations. that more birds than usual didn’t come back in 2016 in 2000, proving that they
Hawk Mountain Sanctuary The miscalculation doesn’t will winter in places people or 2017, when lemmings could make it back to the
in Pennsylvania. necessarily mean snowy can see them. should have been peaking. Arctic.
The solar-powered trans- owls, which can grow to But researchers worry that The National Oceanic and Last week, Smith released a
mitters can last for years, about 2 feet long (60 cen- climate change will af- Atmospheric Administra- young female on a barrier
collecting information such timeters long) with 5-foot fect the owl population tion reported this month beach along the Atlantic
as latitude, longitude, flight (1.5-meter) wingspans, are because lemmings are that the far northern Arctic Ocean. It flew south, then
speed and air tempera- in decline. Scientists simply exceptionally sensitive to is warming twice as fast as circled back and flew over-
ture that is downloaded to don’t know because they even small temperature the rest of the globe. head. As he drove over a
a server when the birds fly never had an accurate changes. But it’s tough to assess lem- bridge to the mainland, the
into range of a cell tower. starting point. Lemmings “depend on ming population trends in owl was sitting on a post,
The use of transmitters, This month, snowy owls deep, fluffy, thick layers of remote areas. Although surveying its new winter
which intensified during the were listed as vulnerable insulating snow” to breed researchers hope to enlist home.q