For the Birds Radio Program: Winter's Last Stand
I spent March 26 at the Sax-Zim Bog, the boggy area around Cotton, Minnesota, on a Minnesota Ornithologists Union field trip led by Erik Bruhnke. The temperature never rose above freezing and the wind was biting, as if ridiculing any thought that Nature respects our paltry human attempts to define seasons by date.
There weren’t any blatant signs of spring—no robins, no Red-winged Blackbirds, no tiny sprouts of green peeking up from the frozen ground. But it being late March, there were plenty of signs of spring—very subtle, to be sure, but filling us with hope. Some signs of spring were disappearances, not appearances. We didn’t spot a single Pine Grosbeak and just a handful of the redpolls that were so abundant in recent weeks. A single flock of Bohemian Waxwings flew over—presumably heading northwest. There are still quite a few Rough-legged Hawks hanging out and a single Northern Shrike, but they were pretty much the last of the winter vanguard. Bird feeders set up here and there in the bog have started disappearing, too, as people maintaining them have turned their own thoughts to spring. The birds hanging out near the feeders seemed to be wishing people could temper their optimism with the realization that until the first real spring growth of plants and emergences of insects, there really isn’t a lot of food left. One Ruffed Grouse was still in winter mode, feeding on buds in a tree. Few animals can digest woody cellulose, but in winter grouse intestines change dramatically—two offshoots called caeca, where our appendix would be, grow incredibly long, allowing them to extract what little nourishment they can get out of those hard buds. Once the ground thaws and insects and fresh seeds and fruits become available, grouse will switch to more digestible fare, and their caeca will shrink.
If winter was still hanging in there, quite a few birds were in the throes of spring’s hormonal surges. We saw quite a few Bald Eagles soaring above, and the first Turkey Vulture and American Kestrel I’ve seen in Minnesota this year. A male Northern Harrier started doing a cool sky dance, and was quickly joined by a second. They were so far away that I wasn’t entirely sure what they were up to. A pair of ravens were also doing their sky dance—that was beautiful to see!
Before we even left Duluth we saw one promising sight—two Canada Geese flying with a Greater White-fronted Goose over Canal Park. Most of the winter it’s been easy to see Common Goldeneyes in the lift bridge canal, but this time that was filled with huge chunks of ice. Once we left for the bog, we were done with waterfowl for the day.
At dusk, we got some clear but distant glimpses of a Short-eared Owl hunting in a logged-over area, and heard a Great Gray Owl’s resonant hoots. But our finest owl experiences of the day were with a Northern Hawk Owl. Usually we think of those as winter birds, but a pair has been hanging out, often heard calling to one another, and are starting to nest. One of them, which may have been the male, spent a lot of time right along the stretch of road where our cars were parked and where 16 people were gawking at her. She wasn’t spooked by us—she spent quite a bit of time preening, which birds simply don’t do when they’re on their guard—and she managed to hear, drop down, and grab a vole at the edge of the road. I just got a new camera, and was thrilled to take photos of her. You can find them at www.flickr.com/lauraerickson.