Thursday, January 19, 2012

Snowy Owl

(Transcript of today's For the Birds)

Snowy Owl

I have a painful confession to make. Here it is, January 19, 2012, a year when news reports from all over the continent and beyond are telling of a Snowy Owl invasion of epic proportions, and I haven’t seen a single one. I’ve driven through Superior and along Highway 13 to and from Port Wing several times this season, and Russ and I scoured the Duluth Port Terminal twice, but I just can’t seem to spot one. I know I’ve seen my fair share over my lifetime, and expect I’ll eventually get one this season, but it’s very strange for me to be so far behind on something this wonderful.

Oddly enough, although the Duluth-Superior area has had a typical number of Snowy Owls this year, we don’t seem to have any more than usual. Meanwhile, they are appearing in places far south of where they usually winter throughout the continent—there have been sightings from Nova Scotia to the Olympic Peninsula, and as far south as Oklahoma, Kansas, and southern Missouri. One poor hapless Snowy Owl flew thousands of miles over the ocean, making it all the way to Honolulu. Unfortunately, the spot it was drawn to happened to be the Honolulu airport. Airport officials decided it posed a threat to aircraft and rather than trapping and relocating the poor, exhausted bird, they shot it.

Snowy Owls in other places have been killed or injured by cars and power lines, and some have been retrieved that were clearly starving. Ironically, this year they didn’t leave the Arctic because of a food shortage—quite the opposite. This was a banner year for lemmings, and the abundance of food ramped up Snowy Owl reproduction. Lemming populations fluctuate wildly, and in response to occasional population busts, it’s believed that some Snowy Owls breed only once in every three to five years. In average years, pairs produce an average of 3–5 chicks, and when food is abundant, as it was this year, they average 7–11 chicks in a clutch. When food is abundant, entire clutches often survive, resulting in a whole lot of owls on the tundra in fall. Owls are territorial in winter, and the birds most capable of driving other birds away get the biggest, most productive territories. Females are significantly larger than males, and adults are more capable of defending a territory than young birds, so the birds that have the hardest time getting territories and are driven south are the young males produced last year. Sure enough, most of the birds that have been identified in the US this year have been young males. As David Evans proved with banded Snowy Owls returning to the Duluth Harbor year after year, some owls do survive the round trip and make it again and again. But there are lots of dangers, especially in the urban and roadside areas where we’re most likely to see them, and many won’t make it.

I’m headed to Florida this week, so unless I manage to pick one out as we’re driving out of town or along the Interstate in Wisconsin, I’m probably not going to be seeing a Snowy Owl until at least February. Fortunately, that’s often the month with the most owl sightings in our neck of the woods, so it still looks good for my finding at least one this year. And that’s hardly going to be our last chance to see them. What with all the owls produced this year, those abundant lemmings have to be decreasing—a family with nine owlets and two parents consumes 1900–2600 lemmings just between May and September. So food shortages next year may drive Snowy Owls our way again. With luck they won’t skunk me two years in a row.