This year has not been a banner year for the Snowy Owl in Massachusetts, but that’s okay. Last year was, and maybe next year will be, too.
Snowy Owls are what we call an “irruptive” species. Some years, for reasons we are yet to fully understand, they descend upon us from the north in large numbers, and not just in New England. Their irruptions reach across the North American continent. For whatever reason – food availability, post-natal dispersal in highly successful breeding years, etc. – they fly south and grace us with their presence.
Massachusetts has a lot to offer the Snowy Owl. The bird is particularly fond of open, coastal, grassy spaces, places that remind them of the arctic tundra. Plum Island on the North Shore is just perfect, as is Logan Airport in Boston Harbor. Duxbury and Plymouth Beaches, and some of the Cape Cod beaches, too, mimic the tundra habitats in winter. Perhaps more importantly these places harbor plenty of food attractive to the “Snowies.” Rodents are a favorite menu item, and the meadow vole (Microtus pennsylvanicus) thrives in the beach grasses, multiplying their numbers every few weeks. Their presence attracts any number of predators, from owls to hawks to coyotes and foxes.
In a pinch, a Snowy Owl will take larger prey, and have been seen in Massachusetts taking everything from ducks to Great Blue Herons. When they arrive on our beaches, they become the instant Kings and Queens of Winter, and are definitely worth an outing to see them.