At first glance, Bearskin Lake does not strike one as unique. It is rather round in shape, and, at 163 hectares, is much larger than our average study lake. But we cover many lakes rounder than Bearskin and several — including Two Sisters, Clear, and Minocqua — that are much larger. Likewise, Bearskin falls into the middle of the pack in terms of average and maximum depth. True, the lake bottom fairly seethes with rusty crayfish, but that nasty invasive species is also abundant in Oneida, Crescent, and Lower Kaubashine. What sets Bearskin Lake apart is not its shape, size, or biology, but the sort of loons that visit and live on it.
I was reminded of the unusual status of Bearskin among loon lakes two days ago when I made our first visit of the year there. I was not greeted by the adorable sight of a loon parent capturing tiny minnows and gently leaning downwards to present them gingerly to its 3-day-old chick, as one might see on Silver, Hodstradt, or Bear. Nor did I encounter a male and female that had tried and failed to hatch chicks and were looking forward to next year, when they could renew their breeding efforts. Instead, I observed a nervous loon that immediately raised its head high upon surfacing to scan for a territorial pair that might take exception to its visit. (Linda’s picture above shows the alert posture characteristic of anxious loons.) This bird, “green over silver, white-blue over orange”, was a former breeding female on Seventeen Lake in Hazelhurst that we had seen only once since 2012. We have no idea what this loon has been doing since we last saw it, but its presence on Bearskin and without a mate suggests that it has been marking time and has not reacquired a breeding position.
Three hundred meters southwest of the displaced Seventeen female was another forager that was far more relaxed on the lake. Like the first loon, though, she was alone. To my surprise, this bird — “silver only, white over yellow” — was the former breeding female from West Horsehead Lake. One of the most prolific breeders ever in our study area, this female has reared 19 chicks since her initial capture in 1996 and, at 29+ years, is our second oldest bird. Her residence on Bearskin solved the puzzle of her disappearance from West Horsehead, which Al Schwoegler (a West Horsehead resident) and I had been mourning all spring long. “Silver only, white over yellow” had finally met a young opponent this spring willing to fight harder than her for the territory. She had thus accepted defeat, left West Horsehead, and taken refuge on the lake where evicted adults have always gone — Bearskin Lake.
I continued my paddle south from the boat landing, feeling that my effort to visit Bearskin had already been repaid. A lone loon foraging just west off the huge island diverted me briefly; I was deflated to find this bird unbanded. As I veered southeast, following the arc of the island, I scanned eastwards and spotted an apparent pair synch diving (i.e. diving and surfacing together repeatedly). These two loons seemed to know me and were no trouble to identify. “Red-stripe over copper, silver over orange” was a vaguely familiar band combination, but I knew his mate, “red-stripe over silver, red over white”, very well indeed. Initially banded on 2001, this female has raised 10 young on Little Bearskin Lake and on Currie, where she had settled in 2015 after her eviction from Little Bearskin. The male with her, I now realized, was her new mate from Currie.
As pleased as I was to encounter the tame pair from Currie, their presence on Bearskin was very bad news. They had hatched two chicks on about June 25th, and had lost one of those by the time Lyn observed them on July 2nd. Since parents attend and protect young chicks assiduously and since we have never observed both pair members to leave chicks unattended until they reach four weeks, the Currie pair’s presence on Bearskin signaled that they had lost the second chick not long after the first and were done breeding for the year. “What are you guys doing here?” I said with a mixture of sadness and disapproval. Bearskin is not a lake where loons go to celebrate their achievements.
My visit to Bearskin ended with an oddity. As I was lamenting the Currie pair’s disappointment, they wheeled around and began tooting to signal the arrival of a flying intruder. The intruder obliged me by arcing towards the Currie pair and skittering to a landing only 50 meters west. The morning sunlight allowed me to read most of its “red-stripe over blue, white over silver” band combination before it hit the water. This male, I knew, was the current breeder from Little Bearskin. His arrival here was more bad news, because males rarely leave their territories during a breeding attempt. “Red-stripe over blue” circled tensely with the pair and then became aggressive, sending both Currie birds fleeing in different directions as he stalked them underwater. Maybe he was stung by his own breeding disappointment. A later check of the database showed that he and his mate had been sitting for at least 32 days on four eggs on Little Bearskin without a hatch. We can reasonably surmise that the pair abandoned a first clutch of two eggs in early or mid May, reused that nest by laying two more eggs with the abandoned ones still present, and now have failed in a second attempt — either because of black flies again or perhaps infertility of the eggs. So this has been a year of frustration on Little Bearskin, as well.
I found two more unmarked loons along the west shore of Bearskin on my visit and no hint of a resident pair or breeding activity. In fact, most pairings on Bearskin are fleeting, and nests are scarce. The last successful breeding on Bearskin occurred in 1997, when a pair fledged two healthy, crayfish-loving chicks, repeating their feat from the year before. Since then there has been a smattering of breeding attempts, but none — to our knowledge — has produced a hatch. Moreover, no pair has ever formed a breeding partnership that lasted more than three years on Bearskin. Loons seem to sense something about the lake that humans do not. Bearskin is not a lake where you go to raise a family; it is a lake where you go when you have nowhere else to go.