A canoe, a spotlight, a net… these are the basic tools of the trade for loon capture. It occurs at night, usually in late summer or early autumn, and typically involves successful breeding adults or their offspring. The technique is predicated upon deception: coaxing the target toward the boat with a series of calls while masking our true identity with the light. There is, with luck, brief moment between the bird’s venture into range and its realization that it is not another loon that it approaches.. a flash of the net. Once secured in hand head covered, wings and feet restrained we take it to shore.
We’ve never managed to come up with a better term than “processing” for what ensues. We apply the leg bands that will enable identification in the weeks, months and years to come. Adults receive one U.S. Fish & Wildlife service “silver” and three homemade, form-fitting plastic colorbands; the combination and positioning of these four hues is always unique. Juveniles, whose gender (and thus eventual mass) is unknown at the time of handling, receive only one tag per leg to guard against an improper fit: on the left a USFWS silver, and on the right a plastic colorband engraved with a two-digit alphanumeric code. Once outfitted with a chromatic identity, we clip a series of feathers from different areas of the body, and even as mosquitoes drain quarts from us collect a few CCs of blood from a vein in the tarsus. We weigh the loon, take some measurements, snap several diagnostic pictures, and then return the bird back to the water. In the case of juveniles, we are careful to release them in close proximity to their parents. The entire handling process generally takes twenty minutes.
No loon enjoys it. While juveniles are usually quite docile in hand, adults can respond more temperamentally. Males, in particular, can turn feisty. By every indication, however, it is an ephemeral imposition. Once delivered back to their aquatic home, their agitation quickly evaporates. From our perspective, it often seems as if the bird has just awakened from a short, unpleasant dream. Come morning, there are no negative ramifications arising from our trespass. Although the species is highly attentive to its plumage, and devotes large amounts of time to preening its feathering, its legs requiring no upkeep go systematically ignored; this does not change with the introduction of colorbands. Common loons do not take notice of them on their own legs, nor on the legs of their offspring, their mates, and their competitors. In procuring a means to unambiguously identify and study individuals for years and even decades, we visit a brief episode of nocturnal stress upon the birds themselves, but nothing more.