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Last year I reported precocious territorial behavior by one two-year-old in Wisconsin and another two-year-old in Minnesota. These sightings were extraordinary. Before 2023, we had no record of an adult loon younger than four years of age holding or attempting to hold a territory. Naturally we were excited to see whether those youngsters would return at age three and continue to show assertive territorial behavior well ahead of schedule.

We were not disappointed.* “Junior”, as I reported recently, is firmly ensconced on the Oneida-West territory in our Wisconsin Study Area. Meanwhile, the now three-year-old who seemed determined to settle on Pig Lake on the Whitefish Chain last July appears to have claimed the Ossawinnamakee-Boozer’s Bay territory…..and is nesting! This young Minnesota male** was hatched in 2021 by the Ossie-Muskie Bay pair. So he has settled only a few miles from the territory on which he was raised three years ago.

It is cool to see two loons in different states set the record for youngest territorial breeder simultaneously. This finding suggests that all adult-plumaged loons, even very young ones, are capable of breeding. The result also implies that many young adults would settle and breed if the habitat were not already occupied by older loons.

Could it be just a wild coincidence that two such unlikely settlements transpired at the same time? Yes, it could be. As someone whose job it is to look for patterns, though, I think I see the beginning of one here. We know from past work in Wisconsin that four, five, and six year-old adults are bigger, stronger, and more competitive for breeding territories than two and three year-olds. We know also that the pool of four to six-year olds looking for territories has become depleted by poor breeding success over the past decade. In other words, fewer chicks fledged has led to fewer young competitors scoping out territories to claim. The sudden settlement of two very young adults in Wisconsin and Minnesota suggests that territorial competition has softened to the point that two- and three-year-olds can now compete for and claim territories.

So the excitement of watching territory settlement by very young adults is tempered by the nagging concern that these events are further evidence of a downturn in the breeding population. But maybe I am overthinking it. For now, let’s savor the spectacle!***

* These cool findings are not mine. Hayden and Claudia, our scouts in Wisconsin and Minnesota, found and ID’d each of these adults on territory. Kudos to these two outstanding field workers, who have braved cold, damp conditions to ID returning breeders in both states!

** I initially called this bird a female on the basis of size. It seems I was wrong. Its settlement so near its natal territory makes the loon almost certain to be a male.

*** The featured photo above is by Claudia Kodsuntie, who scouted our study lakes in Minnesota. It pictures the hind 3/4 of the 3-year-old adult on Ossie-Boozer’s Bay. The photo is not beautiful. I like it, though. It shows the kind of quick underwater view of colored leg bands that one often gets during the early census period. So it gives you a good idea of the challenges that Claudia and Hayden have oversome to make this blog post possible.

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History is afoot on Muskellunge Lake. A two-year-old male is making a play for a high-quality territory….which is pretty shocking. 

Let me put this into perspective. Only about a quarter of all two-year-old loons even bother to return to the nesting grounds. The vast majority of all loons of this young age from eastern and midwestern breeding populations are cooling their heels in the Atlantic right now. Some are off of the Carolinas; some New Brunswick. The bulk of all two-year-olds play the long game: they retain the drab grey-brown winter plumage throughout their first two years, stay healthy on a saltwater diet, and postpone any thought of breeding until they acquire sufficient body mass to compete for a territory in their fourth or fifth year.

We have never observed a two-year-old adult male or female settle on a territory. Indeed, we have only once observed a loon as young as three claim a territory — and that was very late in the season and in a vacant space without competitors. (His mate, sad to say, was his mother.)

As territorial intruders, two- and three-year-old adults are nervous Nellies. They sit low in the water while circling with territorial pairs and are deathly afraid of underwater attack. They peer (look under water) and panic dive obsessively. When anxiety overwhelms them, they freak out and flee across the water tremoloing. In short, two- and three-year-olds do not appear emotionally equipped for territory ownership.

But “Junior”– as Linda calls the two-year-old that has settled on Muskellunge — threw out the book on reproductive maturation. When the 12-year-old male that took over on Muskellunge this year became injured in early June after a failed nesting attempt, Junior took possession of the lake and began defending it vociferously with territorial yodels (as you can see in Linda’s photo, above).

For a time, it seemed that Junior would ease into lake ownership without a battle. Yet news that Muskellunge Lake was up for grabs spread fast in the neighborhood, and the last two weeks have seen multiple local males vie for control. One of these males, from nearby Deer Lake, has tried to claim Muskellunge before and is renewing his bid. A second male, this a ten-year-old reared on neighboring Clear Lake, seemed settled on Harrison Flowage last year but is apparently looking to upgrade. 

Junior’s age is not all that makes his story unusual. He is also the only young adult (out of 211 observed so far) that we have ever observed to compete for ownership of his own natal territory. In this he is fortunate; the current breeding female on the lake, who will probably pair with the victorious male, is not Junior’s mother, but instead a female that took possession of Muskellunge last year.

According to Linda’s reports, Muskellunge remains in an uproar. One day Junior is in control and paired with the resident female (or the Bridge Lake female, whose mate did not return this spring). The next day the Deer male has taken ownership and patrols the lake, searching for Junior, who evades him. 

Linda and I are trying to celebrate the oddity of a two-year-old territory owner and not overthink it. But it is difficult to sit back and pretend to be neutral. After all, Junior got his name because he is the son of Clune, the beloved male who settled on Muskellunge in 2009, cranked out 14 chicks during 14 years of territory ownership, and never uttered a discouraging word for canoe nor kayak.

And it is hard not to wonder how a loon as young as Junior even got a shot at such a good territory. Is his territorial gambit an anomaly — a one-time peculiarity that you are bound to observe once if you study a loon population for 31 years? Or must we interpret his premature, longshot bid for territory ownership as yet another indication of the depleted ranks of young nonterritorial loons that epitomize population decline in the region?