Snowy Owl

When Snowy Owls move into New England for the winter, they attract a lot of attention from both birders and the general public. Part of the draw is that people generally like owls, and another is that Snowy Owls are irregular visitors that aren’t guaranteed every year. Like many species of the far north, these owls are irruptive, and only move south in numbers in relation to their food supply. For Snowy Owls, the key food during the arctic breeding season is lemmings, and when these are abundant more young owls are produced. While adult owls often stay on the tundra during the winter, the young are more likely to wander south in search of food. In fact, most of the Snowy Owls we see in New Hampshire are immatures, and most of those are female. These tend to show more extensive black markings, whereas young males are mostly white and tend to winter closer to the breeding grounds.

When Snowies are in the Granite State the best place to see them is along the coast, usually at sites with lots of open space such as Hampton Beach and Rye Harbor State Parks. Inland they will show up at airports or large fields in the river valleys. All these areas have a certain resemblance to the owls’ flat, treeless nesting habitat in Canada, and if there is sufficient food they may stick around all winter. The winter diet is more varied than the summer, with small rodents supplemented by rabbits and birds up to the size of large waterfowl. Smaller prey are swallowed whole, with their undigested remains regurgitated as pellets, while larger prey are ripped apart and eaten piecemeal.

Because of their remote breeding grounds and highly fluctuating populations, it’s been hard for biologists to determine the conservation status of the Snowy Owl. Here on the extreme southern edge of the winter range, they face threats common to many birds of prey: vehicle collisions (including aircraft), electrocution, and unintentional poisoning, but most owls probably never encounter these dangers. Instead, the greater risk is climate change, which is affecting the arctic, including habitat and prey populations, more rapidly than other parts of the world.