I do not know why I am still surprised by it. Again and again we see territorial females vanish, only to reappear as intruders in their former territory or another in the same neighborhood. The theme has been consistent throughout my quarter-century-long research project on loons. In fact, it is about a 50-50 proposition that a female who disappears from her territory will be resighted nearby in the next year or two.

I suppose the reason why I am always wrong-footed by female reappearances is that I am calibrated to human social conditions. Unlike loons, humans are highly social and benefit from a vast network of family ties and friendships. Humans have evolved to cultivate those bonds — leaning upon family and friends when necessary; providing support, in turn, when called upon to do so. Humans, therefore, rarely vanish without a trace from an area where they have lived for many years. We typically maintain most or all of our social connections even when we shift from one location to another.

Loons, in contrast, are quite alone. To be sure, an adult male or female has the companionship of its mate for several months each year. But this companionship is ephemeral and conditional. When a loon’s mate is evicted by an intruder, the loon faces a stark choice: remain with its mate of many years but move to a new territory, or stay on its territory and accept the evicting intruder as its new mate. Adult loons always spurn their long-term partner and make the coolly pragmatic choice.

Knowing loons as I now do, I should not have been surprised when Linda sent me this crisp photo of an intruder departing from Muskellunge Lake. Although the bird is missing a colored leg band from its right leg, it was not difficult to determine that this intruder is the former female from Manson Lake, who has not been seen since fall 2015. Since loons almost never desert a territory, we can surmise that “Silver over Red, Mint Burgundy over White” (as we affectionately call her) was evicted by the 9-year-old female from Rock Lake in Vilas County who was first seen on Manson in April 2016 and still owns that territory. The eviction forced “Silver over Red” into an itinerant existence. Though you might think that a veteran of 12 years of breeding and mother of 11 fledged chicks had earned better treatment, this 20+ year old now spends her time drifting from one inhabited lake to another as an intruder, searching for a new mate and territory so that she can resume breeding.

It is tempting to pity Silver over Red. These past two years have been difficult and dangerous for her, no doubt. But rather than viewing her and others like her as individuals whose best years are behind them, I always feel an intense admiration for displaced female loons. While many of us humans respond to setbacks with a shrug of acceptance, female loons never stop hunting for a new opportunity.