18 March 2000
On a recent night, when plumes of exhaled air billowed skyward, I located a male boreal in one of the last vestiges of old growth pines remaining outside of the Boundary Waters. The stand mostly survived the July 4th windstorm, but not the fingerprint of land management. Now the understory is gone, replaced by bare earth and frozen bulldozer tracks; a construction site in the forest. But the new openness is the way a pine stand should look and in the long-term, the white pines will flourish. A tablespoon of fire would help the recipe nicely.
The boreal owl was a lethargic singer who did little to excite me as an observer, and obviously, did little to excite the females. During a subsequent, early morning visit, I heard him and then a saw-whet going through their reproductive motions. At the time, nothing seemed unusual as winter closed in the boreal forest. Only after five minutes did I detect the excitement of the male saw-whet. He had company.
Intrigued, I went to the site well before sunset the next evening. Saw-whets, like boreals, start their evening courtship activities well before darkness when a member of the fairer sex enters the equation. At 1827, the saw-whet sang from a nearby spruce bog and then glided to a clump of weathered white pines. He had the throttle open on the accelerator of his courtship song. I moved towards him, simply intent on watching and observing. He sang from a cavity 35' up in a white pine. The female peeped, but I never saw her. I can blame the male boreal for that.
Timing is everything. At 1904, the boreal moved into the white pines and let out two bouts of staccato song. Immediately, the saw-whet went silent. From a "ho-hum," melancholy state of observation, my brain shot to life. I thought about the evening in 1990 when I captured a saw-whet and boreal with bare hands at a cavity site. Surely it couldn't happen again, could it? Well no. But, the events over the next hour did cause me to scratch my head in wonder.
After five minutes, the saw-whet began to sing to the west. He had moved approximately 100 meters to a thick patch of spruce. The boreal? Other than his short proclamation to the night, he was quiet. I moved to the road and listened to the saw-whet. Still excited; still courting. Hey, I was a teen - I could relate. Then the boreal began his song. He was singing less than 20 meters from the saw-whet! For two minutes, it was a battle of the bands. The saw-whet moved, and the boreal followed suit. I noted in my field book that it appeared to be a case of "anything you can do I can do better." Well some things, at least the saw-whet had a female on territory.
Eventually, the two separated and the boreal moved to the east. I left the forest befuddled, but eager for follow-up observations. Last night, however, was the first opportunity I had to return to the site (some things are more important than owls). I sat under swaying white pines hoping for some activity, any activity. Even the rumble of an approaching truck was lost in the tree-creaking din of a low pressure system.
There was activity, just not what I had visualized. I shined my light on the cavity, and tapped the tree lightly with my boot. I expected an owl and got a mammal. Make that two mammals. A northern flying squirrel sprung from the hole. On the backside of the tree, a second flying squirrel stared at me from a weathered limb. Score one for the lactating homeotherms.
In the course of a week, a single cavity resource had produced a diversity of activities. The owls are still there - I know it. But now, their reproductive success is dependent upon their ability to find other, unoccupied cavities. The boreal could probably conduct such a search at his leisure. Something told me, however, that the saw-whet could wait no longer.
Copyright W. H. Lane