Loon Capture in Minnesota

I am fearful of new challenges. In 1993, when I began to study the behavioral ecology of loons on a cluster of 12 Wisconsin lakes, doubt gnawed at me. How can one carry out meaningful, publishable, scientific research, if one’s study animals are large, aquatic, diving birds that range over huge territories, dive constantly, and must be followed in boats? Would my work be severely limited in scope, like that of researchers on porpoises, whales, and sea turtles? I had no training in field techniques for study of aquatic animals, only my childhood experiences paddling canoes over vast stretches of Lake Temagami in central Ontario. But my fascination with loons — which also grew during summers on Temagami — and my sense that canoes could be an effective means of tracking them without altering their behavior pushed me forward. And so, for reasons that I do not understand, I began to treat seemingly insurmountable problems with funding, logistics, and personnel as mere nuisances. And I ignored warning signals that any reasonable young scientist would have heeded. I began to study loons.

So it was in Minnesota. Although one might surmise that beginning a field project on loons in one state would be much like doing so in another, this is not so. True: loons are loons. We see many of the same behaviors, hear the same basic calls, and witness the same sorts of human-loon interactions in Minnesota that we have seen over the past 29 years in Wisconsin. But all else is new. Starting a major field study in the Crosslake area has reminded us that we have an army of friends, lake residents, and supporters in Wisconsin. These folks have housed us, fed us, carried us around in their boats at times, and — most important — provided us with a trove of information on our study animals to supplement our field data.

And our Minnesota study lakes are far larger than those in Wisconsin. Only a masochist would attempt to study loons on the massive Whitefish Chain — where about half of our Minnesota study animals reside — by canoe. So a growing list of Minnesota friends and supporters have provided us with boats — thanks, John, Mike, Mary, Keith, and Dawn! — that permit us to cover the big water. (By the way, several others have made our work possible by providing housing — thanks, Melanie, Charlie, Mary, Jim and Jon!) In fact, we have learned that we can move about far more easily on huge lakes than on the tiny lakes where most of our Wisconsin loons live. Moreover, we can hold our position in the water more effectively and work in greater comfort on the Chain, providing winds are calm.

However, loon capture is another matter. Having caught rather few loons on huge lakes in Wisconsin, I was concerned that my team would waste many hours each night scanning the dark water before our spotlight came to rest upon a tiny light smudge that would become, on approach, a loon parent and a chick that we could capture. In truth, we do spend somewhat more time searching for Minnesota loon pairs that we are accustomed to. Furthermore, locating loon families acoustically is more difficult in Minnesota, because Minnesota loons seem less vocal at night than their small-lake brethren in Wisconsin. But once located, loons in Crow Wing County have proved easier to capture. So my irrational fear that loon capture would be slower and more difficult in our new western study area was unfounded.

What progress have we made in Minnesota so far? Despite the ill-timed failure of an outboard motor that forced us to cut short our night and limp back to our boat landing using only a single canoe paddle and three tote box lids, we have marked 37

adults and chicks in four nights. We banded sixteen loons on Ossawinamakee alone last night. In a few hours’ time, five anonymous territorial loon pairs on Ossie have become a valuable set of individuals whose behaviors, life histories, and survival rates we can track to enrich our understanding of loon breeding behavior and population dynamics. Moreover, our experience in Wisconsin tells us that the brief capture and marking process leaves little or no imprint on loon behavior. Loons caught and marked one night act the next day as if the event never happened. They display the same casual indifference towards us and other humans that they showed on the day before.

On the other hand, we ourselves are greatly changed after we capture and mark loons. Marked loons are individuals to whom we are committed forever afterwards. Yes, we get scientific data from them. But marking creates a lifetime bond between observer and loon. We know these birds. We cheer as chicks we marked return as adults to the study area and claim territories. We mourn when marked parents lose a chick or abandon a nest. And we move heaven and earth to guard these individuals and come to their rescue, if they need it. It has proved impossible to maintain pure scientific indifference to our study animals.

In short, Minnesota loons are excellent study subjects. They ignore our visits to their territories and forgive us immediately after capture and marking. My initial fears and doubts about marking and observing Minnesota loons have subsided. We can now see that we will learn an immense amount about territorial behavior, breeding ecology, and population dynamics of Minnesota loons — if we are willing to shoulder the burden of an intensive field project in a new state on these most engaging birds.