Dan Hirchert is our FAA-qualified wildlife hazard damage biologist. He will occasionally chime in on the blog, sharing insight he’s gained from 20 years of experience in all aspects of aviation wildlife hazard management.
Primarily breeding in the Arctic tundra of northern Alaska and Canada, snowy owls usually migrate south to the United States in small numbers. This year more than 90 birds have been reported in Wisconsin alone!
Periodic irruptions, or invasions, of larger numbers occur every four to six years, often coinciding with population crashes of lemmings in the Arctic, forcing the birds farther south to find food. Sometimes an explosion in the lemming population results in the owls producing a lot of chicks, with many then moving southward to avoid overcrowding and competition. Researchers in the Arctic report near-record high lemming numbers this past summer, which likely explains the high number of owls seen throughout the upper US. Biologists and amateur bird watchers are tracking this movement closely and encourage reporting observations at http://ebird.org/content/ebird/
Snowy owls’ preferred habitat is an open, tundra-like area, which often means they are at airports where they are at-risk of being involved in an aircraft strike. They are known for their prominent daytime behavior that often makes them observable.
Snowy owls frequenting an airport put themselves as well as the aircraft they may encounter at risk. Adults can have a wingspan of more than 48 inches and can weigh up to four pounds. The federal Migratory Bird Act protects snowy owls, and any lethal control requires a permit from the U.S. Fish and Wildlife Service, so airport staff should make the owls unwelcome with persistent use of auditory and visual harassment methods. However, it can be difficult to convince them to find better hunting grounds. Snowy owls often exhibit little fear of people, since they have not had much human interaction prior to their journey. Luckily, this problem is temporary for airports in the US. It’s likely that the snowy owls may stay until late February or early March and then return north as winter retreats.