Snowy owls soar south from Arctic in rare mass migration
By Laura Zuckerman | Reuters – 12 hrs agoRelated Content
Enlarge PhotoA snowy white owl takes flight in this undated handout photo courtesy of U.S. Fish …
SALMON, Idaho (Reuters) - Bird enthusiasts are reporting rising numbers of snowy owls
from the Arctic winging into the lower 48 states this winter in a mass
southern migration that a leading owl researcher called "unbelievable."
Thousands of the
snow-white birds, which stand 2 feet tall with 5-foot wingspans, have
been spotted from coast to coast, feeding in farmlands in Idaho,
roosting on rooftops in Montana, gliding over golf courses in Missouri
and soaring over shorelines in Massachusetts.
A certain number of
the iconic owls fly south from their Arctic breeding grounds each winter
but rarely do so many venture so far away even amid large-scale,
periodic southern migrations known as irruptions.
"What we're seeing now -- it's unbelievable," said Denver Holt, head of the Owl Research Institute in Montana.
"This is the most significant wildlife event in decades," added Holt, who has studied snowy owls in their Arctic tundra ecosystem for two decades.
Holt and other owl
experts say the phenomenon is likely linked to lemmings, a rodent that
accounts for 90 percent of the diet of snowy owls during breeding months
that stretch from May into September. The largely nocturnal birds also
prey on a host of other animals, from voles to geese.
An especially
plentiful supply of lemmings last season likely led to a population boom
among owls that resulted in each breeding pair hatching as many as
seven offspring. That compares to a typical clutch size of no more than
two, Holt said.
Greater competition
this year for food in the Far North by the booming bird population may
have then driven mostly younger, male owls much farther south than
normal.
Research on the
animals is scarce because of the remoteness and extreme conditions of
the terrain the owls occupy, including northern Russia and Scandinavia,
he said.
The surge in snowy
owl sightings has brought birders flocking from Texas, Arizona and Utah
to the Northern Rockies and Pacific Northwest, pouring tourist dollars
into local economies and crowding parks and wildlife areas. The
irruption has triggered widespread public fascination that appears to
span ages and interests.
"For the last couple
months, every other visitor asks if we've seen a snowy owl today," said
Frances Tanaka, a volunteer for the Nisqually National Wildlife Refuge
northeast of Olympia, Washington.
But accounts of
emaciated owls at some sites -- including a food-starved bird that
dropped dead in a farmer's field in Wisconsin -- suggest the migration
has a darker side. And Holt said an owl that landed at an airport in
Hawaii in November was shot and killed to avoid collisions with planes.
He said snowy owl
populations are believed to be in an overall decline, possibly because a
changing climate has lessened the abundance of vegetation like grasses
that lemmings rely on.
This winter's snowy
owl outbreak, with multiple sightings as far south as Oklahoma, remains
largely a mystery of nature.
"There's a lot of speculation. As far as hard evidence, we really don't know," Holt said.
(Editing by Steve Gorman and David Bailey)
