The United States has been invaded.
None of the presidential candidates are talking about it and I haven’t even seen it mentioned on the national news reports yet.
Birders, however, are well aware of this invasion and we welcome our new owl overlords. Yes the country is being overrun with Snowy Owls (Bubo scandiacus), at least relative to how many of these magnificent birds are usually seen.
Since November, thousands have been spotted all across the northern states and even as far south as Oklahoma. The national parks have not been spared. Snowy Owls have been spotted in Pictured Rocks National Lakeshore and Cape Cod National Seashore. One was seen at Breezy point in Gateway National Recreation Area, just a stone’s throw from New York City.
There were also reports throughout December of a Snowy Owl on Cadillac Mountain in Acadia National Park. I can only presume that one was waiting to be the first in the United States to see the first sunrise of 2012. Others have been spotted near Olympic National Park and Theodore Roosevelt National Park.
These invasions are not particularly uncommon. Ornithologists even have a name for the phenomenon: irruption.
This should not be confused with eruption, which is something you’d find at Hawaii Volcanoes National Park, a spot notoriously deficient in tundra-dwelling owls.
Ecologists define an irruption as a sudden increase in an animal’s population. To birders in the United States, it has become synonymous with an unusually high number of a particular northern species arriving here for winter. Redpolls, Bohemian Waxwings, and Three-toed Woodpeckers all have irruptions from time to time, but none seem to generate the excitement of a Snowy Owl outburst.
Snowy Owl irruptions occur about every four to five years in relation to the population of lemmings, their favorite food on the tundra. When these little rodents become scarce, the owls head south in winter looking for food. Sadly, many of the owls forced down to Maine or Michigan are malnourished or virtually starving when they arrive. Many never survive to return north.
This year, the irruption is particularly intense and unique because by all accounts the lemming population was robust this fall. It’s believed the owls have had an unprecedented breeding season thanks to the lemming abundance and there were simply too many birds for the diminished hunting areas in the winter.
Juveniles and weaker adults were pushed out of their territory and before long, some of them found themselves a thousand miles from home in cornfields in Iowa.
Snowy Owls are all born with heavy banding and dark markings. As they age they become lighter colored, with adult males often becoming almost pure white. Most of the owls seen in the United States during an irruption will be heavily marked juveniles, but a pristine white male isn’t unheard of.
My first Snowy of the year was an adult male with hardly a mark on him.
What should you do if you spot a Snowy Owl? First, enjoy it! Not many people get to see one in the wild and it’s a real treat, even for a seasoned birder.
How cool is it to see Hedwig from the Harry Potter movies in the flesh? (For the record, Hedwig was supposed to be a female owl, but its white color clearly marks it as a male. In fact, the “actor” portraying Hedwig was a captive male owl named Gizmo.) So, by all means, appreciate the opportunity to catch a glimpse of these animals.
It’s important to remember a few things for the owls’ safety, however, keeping in mind that these are hungry and desperate birds.
It’s critically important for birders and other observers to keep a respectful distance from owls. Any additional stress to a severely weakened bird could be the final nail its coffin. There are also sad tales of well-meaning birders accidentally flushing a Snowy Owl into a road where it is struck by passing traffic.
These birds live on the treeless tundra of the far north and they don’t like high perches. Since many of the irruptive arrivals here are juveniles, they have never even seen a tree before getting down here. A fence post or rock in a field is a perfectly acceptable perch, and they fly low when startled. Along a busy road, this can be tragic.
When spying on a owl from the road, it’s best to remain in the car. Pull safely off the road, wind down the window and use your binoculars from there. Cars make excellent blinds for any bird of prey. Many of them don’t seem to view a car as a threat, but will immediately fly away when you open the door.
If you see a Snowy Owl, particularly on an excursion to a park or protected area, it’s worth reporting it to the staff at the visitor’s center. Most parks maintain a bird list and for some of them, this year could mark the arrival of their first ever Snowy Owl. Keep your distance, share the experience, and enjoy the irruption!