New theories offered on snowy owls' migration.
For decades, many of us have assumed that snowy owls flew south from the high Arctic when their food supply of lemmings was in short supply. That made sense. The counterintuitive reality, however, is apparently just the opposite -- snowy owls fly south during winters following an eruption of the lemming population.
Smith explained, "If snowy owls evacuated the tundra under starvation conditions, they would arrive here emaciated, with many of them dying along the way. In fact, they arrive here strong and healthy.''
Apparently, in boom years for lemmings, so many of the snowy owl young survive that there's just not enough room for them all up north, and there's considerable pressure among them to disperse. The more there are, the farther they'll need to fly. Part of that nomadic behavior is because of their innate territorial aggression. This year, there are so many snowy owls that they have been found wintering all the way down to Florida.
Corroborating Smith's theory is the fact that the vast majority of the incoming snowy owls -- more than 90 percent -- are immature. If conditions were really bad up north, the adult snowy owls would be coming down here, too, in big numbers. Those dominant birds are obviously perfectly content to stay up north now and monopolize the lemming supply. But not all of the Arctic is producing great numbers of lemmings -- or snowy owls.
Greenland, a huge glacial region that normally should produce many snowy owls, is experiencing less deep snow because of global warming. It consequently has less cover that wintering lemmings need to tunnel and survive in. With less rodent food there, the Greenland snowy owls are producing far fewer young. In many instances, they're not even breeding. Consequently, few if any of our migrating snowy owls are coming from Greenland. But up in much of the rest of northern Canada, 2013 was an incredible year for snowy owl production and winter migration.
While in most years, Logan Airport will host less than a dozen owls -- one year, it actually hosted only one -- well over 100 have occupied the runways this year. Smith has captured more than 90, transferring them to safe, open places like Duxbury Beach and Plum Island, where they pose no collision danger to planes. His work is not without risk.
Snowy owls look white, soft, cuddly and cute. But they're powerful, aggressive killing machines with talons that can quickly kill a duck or permanently injure a hand. The snowy owl is the most massive owl in all of North America, much more powerful than a great horned owl or great gray owl.
During his BBC lecture, Smith delighted everyone by pulling out of a box a live snowy owl he had just captured at the airport. It was obviously having a strange day, as Smith carried it up and down the aisles without a glove close to the several hundred awestruck members of the audience. Later that night, long after his program, he brought the bird to Duxbury Beach for release.
But before he did, Smith went on to further debunk the myth that snowy owls are exclusively diurnal hunters.
"Here at Logan, they typically hunt at night using their incredible vision and extraordinary flying skills to go over water in the darkness and easily grab a duck for a late dinner,'' he said.
While there are many species of locally wintering waterfowl for them to dine on, black ducks are No. 1 on their menu, largely because they typically try to fly up and away from the pursuing snowy. Since snowies are incredibly fast, able to reach about 62 mph, they easily catch up with and grab the flapping blacks. On the other hand, ducks -- like buffleheads -- avoid pursuit by diving straight down. Snowy owls won't dive into water in their pursuit.
Snowy owls also hunt many other nocturnal species, including barn, great horned, barred, saw whet, short-eared, and long-eared owls. They also kill and eat other snowy owls. Smith recently had to take one severely injured snowy to Tufts Veterinary Hospital for surgery to save it. When snowy owls come south, they're hungry. They don't want to share their feeding territory with any of their kind.
Smith also debunked the belief that we can age and sex a snowy owl in the field just by determining the amount of black and white in its plumage. Most of us incorrectly believed that adults were nearly all white, while immature snowy owls had considerable black barring.
The reality, Smith has found, is that the amount of black barring is not an accurate indicator. The only way to verify their age and sex is to have the owl in hand and examine the pattern on its flight feathers. And that has to be done with extreme care. Both man and owl could be badly injured in the process.
Smith doesn't get paid for his owl work, which is truly a labor of love. He traps and relocates them all either before or after work. That means often getting into the field around 3 a.m., or well after dark and being very late for dinner. Mrs. Smith is a very understanding wife.
The alternative to this stressful schedule is to let airport staff, who are relatively inexperienced and far less competent, do the capturing and relocating, and possibly injure the owls in the process. Smith never uses a glove because owl leg bones are extremely fragile. Being bare-handed helps him adjust pressure as needed without breaking the legs. Few people who handle owls dare to do so without a glove.
Smith helping snowy owls at Logan has been an inspirational model for other airport safety staff around the country. He has led the way in showing through his catch-and-transfer strategies that snowy owls don't have to be killed on runways to reduce collisions. Thankfully, he's far from finished both saving owls and teaching all of us who are concerned about their survival -- and for reminding us that we all need to be open-minded and receptive to truth, even when it undermines some of our long-held beliefs.