Nature Notes: Snowy Owl
Thick, soft snow swirled to the ground as I walked quietly along the path. Approaching a post I had passed many times, something seemed out of place. It dawned on me that there was a large white bird squatting on the post, seemingly unaware of my presence. As I came within 25 feet, I realized it was a snowy owl. Even though I was along Lake Ontario in NY, on a major migration corridor for raptors, I was surprised to see one of Nature’s largest owls more commonly associated with Arctic regions.
Such sightings are more common this winter in Maine and other Northern states. Birders have reported seeing numbers of these beautiful birds up and down our coastline. I had the good fortune to see one sitting in the snow near the Carrying Place on Route 123. On Christmas afternoon, my family came upon some birders at Land’s End on Bailey Island. Using a spotting scope, they were able to observe a snowy owl sitting on the roof top of the lone house on Jaquish Island.
It appears that due to recent mild winters, nesting success for the owls has been high, leading to a population boom. They are very effective predators, favoring small rodents, in particular lemmings. As winter cold descended, the owls began to experience food shortages as the population of prey species became over harvested. Juvenile owls were pushed out of their normal habitats and ended up migrating south in large numbers. This is mostly to our benefit, although the owls have been causing problems at some airports as safety managers scramble to avoid bird/airplane collisions.
These birds are stunning creatures, with yellow eyes and black beaks. Adult males are almost totally white, while females and juveniles have varying degrees of black banding or spotting in their lush feathers. Even their heavily taloned feet are feathered since retaining body heat is critical to survival in harsh northern winters. Thanks to evolution, these birds are heavy bodied and have a big appetite so they can generate and retain adequate body heat. They typically nest in the far north of Canada and Alaska at latitudes above 60 degrees N.
A pair of owls will scrape out a rather bare nest on top of a mound or large rock, or use an abandoned eagle’s nest. The female may lay as many as 10 eggs, which must be guarded for 5 weeks until hatching. Both male and female will guard the nest, using aggressive flights or distraction displays, depending upon the size of a predator focused on stealing their eggs or chicks. Both adults search for food, which may range from rodents to birds, rabbits, snakes and prairie dogs. The birds normally take their prey on the ground but are capable of snatching targets off the surface of lakes or ponds. Prey is swallowed whole or torn apart with their sharp beaks. Strong stomach juices digest the flesh, while indigestible materials like bones and hair are regurgitated in small pellets that are the telltale signs of a favored roosting spot.
Given their size and solitary habits, snowy owls have few predators. Arctic foxes, gray wolves and raptors such as eagles and faster peregrine falcons are capable of taking their eggs or immature birds. The biggest threat to these gorgeous birds are the cyclical changes in the population of their favored prey species and ecological changes brought on by global warming. As with snow geese, rising populations of snowy owls have resulted in large winter migrations in recent years, bringing them close to our homes so we can enjoy these unusual visitors in all their glory.
If you like Ed Robinson’s writing, check out his two Nature Notes books! Click here for more information.