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“Wow”, Lainey said, “that band number is right next to the female we caught last night on Sherry”. She was right; the adult male from Skunk, which we had just netted and whose band number I was reading aloud to Lainey for data entry during banding, had a number imprinted on his aluminum USGS band that followed immediately after that of the Sherry female from the previous night. The reason for consecutive bands is that the Sherry female is the mother of the Skunk male and was caught and banded with him a decade ago (less two days) on Sherry Lake. I remember July 31st, 2005 on Sherry vividly, because I was equipped with a video recorder on top of a helmet with which we recorded the capture process for research presentations. But the recapture of mother and son on back to back nights ten years after we had first marked them has also caused me to reflect upon several key features of loon biology that have become familiar to me through my work.

First, loons live a long time. In this twenty-third year of my work, I still encounter birds in the study area that were on territory, as adults, when I first started covering them. Females, in particular, are survivors. While males have rather high mortality –partly owing to their proclivity for battling dangerously — females linger. When their mate dies, females find another; when a female is evicted unceremoniously from her territory, she stoically moves to a new lake nearby and awaits a chance to re-insert herself back into the breeding population. So it goes with the Sherry female whose worn-out band from 2005 is pictured on the bottom in the photo. She was “widowed” suddenly in 2009 (a possible eagle kill) but hung onto her territory and was joined by a new male in short order, who has been her mate since.

Second, young males do not disperse far from their natal lakes to breed. The Skunk male, from whom we removed the top band in the photo last night, moved about 15 miles from his natal haunt, Sherry. That dispersal is, actually, a bit longer than average for males, many of whom settle to breed on a lake adjacent to where they hatched years earlier. Short-distance male dispersal is essential to my work; without it, I would not have a large marked cohort of 2 to 5 year-olds of known age and natal origin in the study area at all times whose territory settlement strategies could be investigated. (At last count, we had seen 295 adult loons in the study area that were marked originally as chicks.)

Third, loons vary tremendously in their behavior towards humans. My assistants and I dread the Sherry female, because she is the most skittish individual we know. She cannot be approached easily within 100 meters on the water; she tremolos (i.e. alarm calls) incessantly when a chick is present and a canoe appears on the water. In fact, my assistants tell me that she begins to tremolo in anticipation of a canoe being placed on the water and that they have begun a strategy of hiding behind bushes and trees along the shoreline in order to make observations of her when she is with the chick. (Fortunately, Sherry Lake is tiny, so this observation strategy is workable.) I joked that we should wear camouflaged clothing when visiting Sherry; my assistants did not find this funny. Oddly, the Sherry female’s mate is among the tamest loons we study and never tremolos at us when we collect data there.

The great variety in loon tameness is a topic of great interest to us, as I have mentioned. It amazes me that an adult such as the Sherry female could react so strongly (and, it would seem, maladaptively) to humans, which she encounters constantly. Doesn’t she waste energy with her fruitless calls? Shouldn’t skittish birds like her leave fewer offspring and live shorter lives than other adults who tolerate humans without constant complaint? If so, she is not a good example of the pattern, as she has behaved this way for the ten years we have known her while cranking out chicks. Indeed, the Sherry female and the Oneida-East male, another vociferous but fecund individual with whom my staff has to cope, make me wonder if I have got it backwards. Maybe loud-mouthed loons warn humans away, lessening the likelihood of injury to themselves and their brood, and are rewarded with high evolutionary fitness.

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It is human to overgeneralize based on the chance co-occurrence of rare events.  As a scientist, I know this. I spend a good deal of my research time sorting through quantitative patterns in data, fending off the tendency to infer a meaningful biological pattern where only chance trends are present.

And yet, the events at Alva Lake last night shocked me. The Toussaints, dear friends who live on the lake and kept me alive during my first year of loon research in 1993, had informed me before my team attempted capture of the breeding pair and their month-old chick that the male had been holding his leg strangely, as if injured. My crew had reported no abnormal behavior of the pair; indeed, I had seen only normal territorial and parental behavior when I had scouted the lake for capture at noon. Still, the Toussaints are careful observers of loons, so their statement gave me concern. I told them as we cast off from the dock that we would try harder than usual to catch the male, just in case.

Capture was swift and uneventful. Both pair members sat protectively on the lake’s surface as we approached slowly and scooped them into our net. After catching the chick as well, we headed back to the dock feeling good about ourselves. Not until we inspected the female’s legs on shore did we detect anything amiss. As the photo shows, the female’s left leg was encircled tightly just above the foot by Dacron fishing line (used commonly in Wisconsin for muskie fishing), and a 5cm-long thick snarl dragged behind. The line had become tight enough to bite into the leg and cause a painful wound. Taking great care not to worsen the wound, we cut through the super-strong line and removed it. Fortunately, the entanglement appears to be recent, the wound superficial. The female should recover fully within a week.

Surrounded by three generations of Toussaints and still jittery from seeing the female’s leg, we were ill-prepared for the sight of another, more severe injury on the male. In this case, monofilament line had become wrapped around the leg just below the ankle joint. Again the line was constricted tightly around the leg, but this entanglement had occurred many months ago and the skin and keratinized scales of the loon’s legs had overgrown and surrounded the monofilament strands, leaving the circle of line protruding to the outside via two holes in the skin, like an earring. Though absorbed and surrounded by leg tissue, the line had caused local inflammation, as revealed by the irregular swelling in the adjacent portion of the leg. After an emergency consult with Mark Naniot of Wild Instincts, we resolved to pull out the line if we could do so without doing further harm to the bird. Fortunately, once cut, the line slid easily out of the holes, revealing infection but an injury from which the bird should recover.

Shaken as I am by seeing back to back angling-related wounds, I chalk up the discovery of two such similar injuries within a mated pair mostly to chance. That is, there is no reason to suppose a sudden, devastating impact of fishing line on the health of common loons. After all, we have captured dozens of other loons this summer that showed no ill effects from having lived in waters plied constantly by all manner of fishing lines, lures, baits, bobbers, and sinkers and riddled with tangles of line left behind by grouchy anglers. All but a few loons we have seen have thrived for many years in Wisconsin waters, despite this piscatory onslaught.

So what can we learn from the events of last night on Alva Lake? Two lessons, I think. First, loons are tough. Designed for maximum strength and minimum thickness, fishing lines bite deeply into animal tissue when forced against it. The Alva pair, no doubt, experienced severe discomfort and some loss of circulation. Yet they completed two months of incubation, chick-rearing, and territorial defense and stand to survive their brushes with fishing line without permanent damage. Second, angling exacts a steady toll on loons and other wildlife. Loon populations are stable or perhaps even increasing slightly in northern Wisconsin. It is becoming obvious, though, that sustaining loon populations in areas where anglers are more abundant every year will require concerted efforts of those who love loons.

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We are riveted on the happenings on Flannery/Velvet Lakes. On these two lakes –united through a narrow channel so as to be a single waterbody — a tense scene is playing out with elements of a Shakespearean tragedy. A 13 year-old male, hatched on Townline Lake and a frequent intruder into various lakes in and just west of  Rhinelander, is opportunistically seeking to replace the deceased Flannery male. If he succeeds, he would shift from a territory on the Wisconsin River, where he has failed to fledge chicks despite three years’ of nesting attempts, and settle on a new lake that just this year produced chicks, breaking its own eight-year skein of nesting futility. In other words, this would be a step up for the male.

This male’s effort to relocate to a more productive breeding site has taken a dark turn. While visiting Flannery and bonding with the widowed female there, the male encountered her young chicks. One of those chicks the male killed weeks ago by pecking it to death when it was quite small. The surviving chick too has suffered repeated beatings by the male to the point where the chick now spends much of the day hiding underneath piers on Velvet Lake to avoid the abuse. This grisly spectacle has had severe consequences, as the chick is only about 60% of expected body mass for its age. Clearly the physical beatings the chick has suffered, the presence of only one parent, and the inability of the female to feed her surviving offspring to satiation while defending him from intruders threaten his survival. It remains highly uncertain whether the chick will reach adulthood.

I had expected that the dreadful treatment of the Flannery/Velvet chick by an intruding male would make me feel a gut-level hatred of the intruder. Indeed, I was horrified by the fiasco unfolding there. But knowing that the male wreaking this havoc is an old friend of ours — one that I watched as a chick on Townline Lake back in 2002, a young floater on Langley, Julia and Hanson lakes, and finally a failed breeder on Wisconsin River — has complicated my perspective. I am rooting strongly for the chick to survive the vicious onslaught, start to forage for itself, and fledge. But I am also cheering a young male loon who is trying to turn his life around by moving into a new territory that offers the promise of abundant fatherhood.

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Two days ago, Mark Naniot of Wild Instincts got a report that a loon on Two Sisters Lake had been hooked by a fisherman in the leg and was trailing 50 feet of monofilament line and a bobber. Mark learned also that a well-intentioned kayaker had approached the loon and cut much of the line, including the bobber, but leaving the hook and several yards of fishing line trailing. Having captured and unhooked a loon several weeks before on the same lake, we were disappointed to hear of another angling incident. Could the same bird have become entangled again?

Seth happened to be collecting data on Two Sisters Lake yesterday. He found the impacted loon, which was not the Two Sisters-West male that we had rescued in June but the female from Two Sisters-East. (The lake has east and west halves, each with a successful loon pair.) Seth reported that the female was using her right leg sparingly, trailing fishing line, and had tried but failed to take off and fly on several occasions. She was not with her mate and two young chicks. Clearly the bird was in trouble.

After digesting Mark and Seth’s reports, I turned my attention to the prospect of catching the impacted loon. I viewed the challenge with mixed feelings. On the one hand, this female, hatched on Crab Lake in Vilas County in 2004, was well-known to us as a rather tame individual, making capture more feasible. On the other hand, we had captured her four nights earlier, which raised the possibility that she would recall that event and be more difficult to approach a second time. The most crucial card we held was that the female had chicks to protect.

Several major research programs that focus on common loons in the northern U.S. and Canada rely, more than any other factor, on the ability to approach adult loons closely at night and net them when they have chicks. If researchers could not approach adults closely during this reproductive window, we would not be able to mark them and study their behavior, health or survival. We would therefore be unable to generate models to determine whether loon populations are increasing or decreasing. In short, loon research would grind to a halt without the presence of chicks to freeze adults on the surface and permit us to catch and mark them.

Last night’s adventure served as a vivid reminder of the value of chicks to adult capture. We began searching for the hooked female shortly after nine p.m. and located her quickly along the southwest corner of the lake’s eastern half. Her behavior was odd; she seemed to restrict her movements to one small portion of the lake and was not anywhere near her mate or two large chicks. She held her hooked leg out of the water when resting on the surface. Before full darkness, we spotlighted and approached her to attempt capture, but she repeatedly dove before we could get within a net’s reach. Although frustrating, this cheered us a bit, because it showed that she was still relatively healthy despite the hook. At the same time, we were vexed to see that a loon that was in dire need of human assistance and which we had scooped out of the water with ease four nights before was resisting capture. We made several more passes by the female, until it became clear that the distance at which she dove was increasing rather than decreasing. We had a loon in need of help, a huge staff from Wild Instincts on shore waiting to assist it, and no obvious means of catching the bird. The critical ingredient missing was her chicks, which were nowhere nearby and which, we felt, might have held her on the surface and permitted us to net her.

We shut down the motor and listened. As luck would have it, an adult loon tremoloed far to the northwest, near the small bay where the Two Sisters-East pair had nested. Eric drove us up to the northwest corner, where, after 20 minutes of searching, we located the male and two chicks. Freshly banded from four nights before, the male and two strapping youngsters were nonetheless easy to net and pull into the boat. We set out southwards, where we had left the recalcitrant female, and released all three birds there. After several minutes of silence, the just-released male finally wailed and an answering tremolo came from 400 yards southeast. Again, we were in a bind, because the female had clearly swum a good distance away, where she would not soon encounter the chicks that we had released in hopes of capturing her. So again we netted a chick — leaving one near the male — and motored southeast to where we had heard the female. Having glimpsed the female for an instant before she dove, we gently held the chick in the boat until it vocalized. The injured female was transformed: she immediately sat up in the water, alert, and wailed to call her chick to her. We released the chick, the two reunited, and the female remained alert and protective next to her chick as we slowly approached and netted her.

After all of our efforts, it was rewarding to learn that, while the hook had punched cleanly through the female’s leg a few centimeters above her colored leg bands (see photo, courtesy of Wild Instincts), the prognosis (according to Mark) was excellent for recovery.

Looking back, we spent three hours capturing a family of loons that we had just caught and banded four days earlier. The rescue was a major production, requiring us not merely to locate and capture her but to find and capture her family in a remote location on the lake and transport them to her vicinity in order to restore her parental instincts and permit us to approach and net the impacted loon. This effort threw a wrench in our capture schedule, necessitating that we rush to three more lakes to capture loons there and cancel plans to attempt capture at two more lakes. Still, our team effort with Wild Instincts left us glowing; we had rescued a loon in peril and given her a chance to return to her life as a plucky protector of two young offspring.

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For the past several years, we have covered Blue Lake, which contains two loon territories: Blue-West and Blue-Southeast. Blue-Southeast is the more productive territory. In fact, it has produced chicks for the past 3 years. A few nights ago, we captured and banded the two chicks and female from Blue-Southeast. We thought nothing amiss in finding the chicks with only one parent; it is common during both day and night for either male or female to watch over the chicks while its mate wanders off to feed on its own.

What was odd that night was that, on our trip to return the Blue-Southeast female and chicks to their territory, we blundered upon a banded loon pair where none should have been in an area that might be called “Blue-Central”. We captured one of this new pair (a six year-old female hatched on Franklin Lake, some 40 miles east). The other pair member, it seems, was the male from Blue-Southeast! While it is tempting to make some tawdry comment here about the skirt-chasing tendencies of males, this was not a case of the Blue-Southeast male cavorting with another female while his mate cared for the chicks. In fact, the new Blue-Central male had been evicted from Blue-Southeast several days before, which forced him to leave his chicks in the care of his mate and the male that had evicted him. Moreover, reports of a banded and injured bird on Blue in the few days prior to our visit lead us to believe that the vanquished male had been seriously injured in the battle that cost him his territory and separated him from his mate and chicks. (Clearly he had recovered from his wounds by the time of our visit.)

The current situation on Blue-Southeast is a bit worrisome and quite similar to that on Flannery Lake. There too, the territorial male was lost during chick-rearing, forcing the female to care for the chicks alone, while seeking to re-pair with a new male. On Flannery, a new territorial male killed one of small chicks — though the other is alive and now 6 weeks old. On Blue-Southeast, the chicks were far older at the time of eviction, but a recent visit by Seth revealed that the new male (sadly, an unbanded bird) is paired with the female and is pecking at the large, healthy chicks and not feeding them. Based on past observations, we hope and expect that these chicks are old and strong enough to mature and fledge despite their step-dad’s hostility, providing their mother continues to feed them. However, the awkwardness of a mother-stepfather pair with chicks seems to have consequences. The Flannery chick, captured and weighed a few nights ago, has far lower body mass than he should for his age. Let’s keep fingers crossed that the Blue-Southeast chicks, which are strapping youngsters at present and live on a large lake with a strong record of fledging chicks, can weather this parental storm.

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Since I am trying to turn the corner after yesterday’s disaster, I am happy to announce that Gabby Jukkula’s and my paper is now available. The editor at Journal of Avian Biology seemed pleased with the article; he asked me to produce a short blog post for their website, which I did. It describes the genesis of the article, the preeminence of male parents in defense of loon chicks, and a rare case in which a male parent died when his chick was less than a week old and his mate beat the odds to rear the chick to adulthood without him. Perhaps the glow of having the article and blog come out will cheer me up!

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LMG_5401 Crystal Lake NestOn its face, the photo is comical. A loon sits on its egg on a swim raft, a meter from an American flag. A garish McMansion is visible on the opposite shore. Few photos of the common loon are more at odds with the image of the species as a symbol of the northern wilderness. Yet Linda Grenzer’s photo of the nest on Crystal Lake is a poignant portrait of the situation faced by most territorial pairs in north-central Wisconsin.

Many popular accounts describe common loon populations as holding on for dear life. To be sure, loons are threatened by shoreline development, which reduces nesting habitat. Recreational fishing and boating kills many adults and chicks prematurely each year. And methylmercury in the food chain, swollen by coal-based power production, likely impacts the loon population as well.

Against all odds, however, loons appear to be holding their own in northern Wisconsin. Despite consistent losses caused by collisions with boats and entanglement in fishing lines, populations have bounced back in recent decades. The surprising resilience of loons seems to result from two facts. First, loons prefer to nest on small islands and on boggy and marshy habitats that humans avoid. Thus, loon pairs continue to produce young on lakes that are virtually encircled by human dwellings. Second, as illustrated in the photo, loons tolerate — and rarely even benefit from — human alterations of aquatic habitats.

The pair on Crystal Lake, whose nest is pictured, were in a real bind. Crystal is a very pleasant lake, but it lacks islands — the nesting spots most favored by loons — and also features neither bog nor marsh. Previous nesting attempts by the male (reared on nearby Muskellunge Lake in 2006) and a parade of 3 or more different females since 2011 ended in abject failure, the eggs an annual donation to local raccoons. Although they crawl onto it with great difficulty and complete loss of dignity, the Crystal pair decided a few weeks ago to place their nest on a low-lying swim raft. The raft is high above lake level and not equipped with any sort of ramp to assist small chicks in re-mounting the raft once they have entered the water, so we are concerned that the chicks will not be able to return to the nest (to be kept warm by a parent in the first few days of life) once they have left it. Still, the likelihood of hatch is good, and Linda and her helpers placed nesting material on the raft to keep the eggs from rolling off. We are hopeful that the loons can cope with the problem of nest height just as they do with a host of other anthropogenic obstacles each day in northern Wisconsin.

I shall keep you informed. If the Crystal pair can hatch and rear their chick to adulthood, they will be a vivid example of the capacity of loons to adapt and thrive in an environment thoroughly dominated by another species.

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LMG_4295 one day old chick on back

After 2014’s disastrously low chick production owing to black fly infestation, I was anxious that breeding success would rebound in 2015. My concern defied reason. Loons are long-lived, of course, and a few or even several consecutive years of below-average chick production are not enough to have a lasting negative impact on the population. Still, blinded by the irrational human tendency to infer long-term impacts from short-term patterns, I wished to see our loon pairs come back and raise many chicks in 2015, just as Linda Grenzer’s pair has (see photo).

This year is shaping up to be a very good year indeed. As of this date, 31 of the 120 territories we follow (25.8%) have already hatched chicks. In contrast, only 2 breeding pairs (of 112 pairs; 1.8%) had chicks on this date in 2014. That is an unfair comparison, because the black flies devastated early nests in 2014. However, 2013 was a rather good year for chick production, and in 2013 only 20 of 108 pairs we followed (18.5%) had chicks on this date. Although these data are slightly biased because of yearly differences in nesting schedules — that is, 2013 was a slightly later year than this year — 2015 should be an awfully productive breeding season for loons in northern Wisconsin. As a scientist, I am breathing a huge, sheepish sigh of relief!

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The Loon Project counts on efficient exchange of information with lake residents and loon enthusiasts as a means to acquire good scientific data. We cover enough lakes — about 120 this year — so that we make visits to them only once every 5 to 7 days. This permits us to track the identity of the breeding pair and record their breeding activity. Over time, we accumulate important data on territorial fidelity, eviction of breeders, and their relocation to other study lakes. But weekly hourlong visits leave lots of holes in our knowledge. So it is helpful that almost all of our lakes are occupied by humans who take an interest in “their loons” and contact us or the Wisconsin Department of Natural Resources when something is amiss.

Yesterday, a resident on Flannery Lake called with distressing news. The male on the lake, a 14 year-old reared on Washburn Lake, was dead and being fed upon by a mink. We were particularly saddened to hear such a report from Flannery, because the breeding pair had attempted to rear young every year there since we began to follow them in 1993, but had not fledged a chick successfully since 2006. That unlucky string seemed about to be broken when, earlier this month, the pair hatched two vigorous chicks. We were delighted, though perhaps less so than lake residents, who had watched their loon pair build nests, lay eggs, and incubate them diligently year after year only to lose them — or their small chicks — for reasons unknown.

This morning Seth visited the lake to see whether the female and chicks were still alive and whether another male had taken the deceased male’s place. He snapped the photo above, showing that the female, who is at least a quarter of a century old, is alive and well, as are both chicks. However, he also reported that a possible incipient pair was present on the lake. This makes sense. As I have noted in recent posts, male loons use their yodels to keep hopeful settlers at bay. With no male present to yodel, intruders flying overhead readily land in the lake. Since the female cannot safely leave the two-week-old chicks alone, she cannot easily engage intruders and drive them off. In short, Flannery is prone to intrusion and settlement.

Despite the difficulty of her situation, Seth reports that the Flannery female continued to show territorial behavior towards intruders this morning. It remains to be seen whether she can find refuge on the lake such that she can both avoid any new pair that settles and forage to sustain herself and her young chicks. It is a tall order. Indeed, we have only once observed a female whose mate died or was evicted raise a young chick on her own. In 2012, the male on Squash Lake died of lead poisoning owing to an ingested sinker, leaving his mate and a chick only a few days old. The Squash female that summer miraculously succeeded both in rearing the chick to fledging and in pairing with a new male — a lesson to us all that child-rearing need not prevent an active social life. “Miracle Chick”, as we came to call the survivor on Squash, became our most revered juvenile that year. (Miracle Chick is pictured below with Kristin and Gabby.) Lauren's capture video and stills 082

So there is reason for hope for the young Flannery chicks. If she is vigilant and fortunate, a female can raise a chick, perhaps even two, without help from a male. Considering the long odds of such an achievement, we should certainly resist optimism at this point. We will keep an eye on this fractured family, and I will let you know how things turn out.