Wild Instincts

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2015-07-27 22.02.28

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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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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2015-06-12 22.17.05

In his routine visit to Two Sisters Lake to check on the status of an incubating pair, Chris was alarmed to find out that the male had a hook lodged in his cheek and fishing line protruding from his bill. This male — captured and marked in 2010 as a breeder on Brown Lake before being evicted two years later — had been a “floater” for the past three years before replacing the absent Two Sisters male this spring. I was thrilled to see this tame bird get his life back together.

When Chris reported the hook in this male’s bill, I wondered if this bird was just snakebit. The entanglement could not have occurred at a worse time. The male and his mate were on the brink of completing four weeks of incubation and hatching of two chicks, which require great care and protection at this stage. Indeed, between yesterday morning and afternoon, the male had finished incubating the second egg and left the nest for good with two head-sized chicks alternately hiding under his wing and riding on his back. Attentive as he was, the hooked male was ill-equipped to defend his brood. As we have learned recently, male loons are especially vital to the defense of a pair’s young chicks, because the male-only yodel discourages landing by intruders (which, on occasion, kill young chicks) and because males are active defenders of chicks towards intruders that approach them in the water. With the hook lodged in his mouth, the male was unable to open his bill, and his protective vocalizations yesterday were so muffled and distorted as to be ineffective.

Upon receiving the report of the hooked male yesterday, we agonized over the decision of how to proceed. Adults with small chicks are the easiest to capture, so we were not worried about catching the male. However, one must take great care when young chicks are present, as they are tiny and are always on, next to, or underneath the wings of the adults. When one is netting the 10 to 12 pound parent and hauling it into the boat, it is conceivable that an unseen chick might be crushed beneath it. Would it be wise to wait for a few days or a week, until the chicks were larger and stronger, before attempting capture? In the end, we decided that the male was impacted enough that we were endangering his life and those of the chicks if we did not act immediately to help him. So last night, Joel, Eric and Seth set out on Two Sisters to try to: 1) gently separate the tiny chicks from the male, and 2) catch the male so that the hook could be safely removed by Mark Naniot of Wild Instincts, who was standing by on shore.

As you can see from Seth’s photo, we caught the male, and Mark expertly removed the hook from his cheek. The chicks were unharmed in the process. The male seemed in good shape, considering his close encounter with an angler’s line. (We suppose that he became hooked only a day or so before we caught him.) Still, we shall be checking today to see that the family is back to normal. While there are many dangers facing loons in the first few weeks after hatching, the team of rehabbers and loon researchers has given them a chance to confront these dangers without human impacts layered on top!

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In most cases, loons die when they are hooked by fishing lures or snarled in monofilament line. Cases in which birds are able to free themselves and recover — or we catch them, nurse them back to health, and they put their lives back together — are the exceptions. So we are thrilled to report that the 9 week-old chick that was hooked in the leg, captured by our team, and placed on antibiotics by Wild Instincts to rid it of the resulting infection, was released on its natal lake last week and is now behaving normally. Indeed, Gabby saw it circle its lake three times in flight shortly after release.

Juvenile loons have a relatively short window during which they must: 1) learn to capture fish and invertebrates underwater, 2) learn to fly, and 3) develop large enough fat stores to migrate south to Florida for the winter. It seems remarkable that this youngster has bounced back from its dangerous encounter with humans to the point that it might be able to make the journey with its cohort.

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We have reached the time in late summer when — following many trial runs, crashes and ugly landings — chicks have begun to fly. But chicks do not always take wing, circle and land in their own lake. They wander. The picture below was taken on September 17th by Bonnie Montgomery of Fifth Lake, east of Rhinelander. She caught the legs on a departing loon well enough that we could identify it (see two bands on right leg pointed out by green arrow) as one of the two chicks raised on Buck Lake, south of town.

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We have a keen interest in the local wandering of chicks like this one. Following our finding that loons settle on breeding lakes that are similar to their natal lakes, we are interested to see how this preference takes shape. Perhaps loons spend their entire lives preferring to live and forage in lakes of a certain size and water chemistry. If so, this lifelong predilection should make itself known early. That is, juveniles that begin to fly and visit lakes near to their natal lake should prefer lakes similar to the one on which they were reared.

Kristin and Gabby this year, Nathan last year, and Joel in 2011 have examined the hypothesis that natal site matching (as we call the preference of a loon to breed on a natal-like lake) is evident even in the local wandering of chicks. It will take a good deal of data to examine this hypothesis, but we are hoping that our crew will collect enough data (especially after this year’s bumper crop of chicks) to make statistical analysis possible.

Speaking of Kristin, Gabby and Joel, they caught another chick tonight that had become hooked in the neck by a lure and snarled in two types of fishing line. Luckily, the hook did not penetrate deeply. The lure was removed by Mark Naniot of Wild Instincts, the line was cut off of the bird, and the juvenile was released, still apparently in good health. 2013 has been a very bad year for loons and fishing!

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A week ago, a fisherman hooked a juvenile loon in in the leg. We know the juvenile well; it is a chick that hatched 9 weeks ago whose parents and territory we have observed all summer. As a 9 week-old, this chick is close to adult size. At the time of the accident, it was feeding itself for the most part and beginning to practice taking off and flying. The fishing lure changed that. With a hook embedded in its left leg and monofilament line wrapped around the leg, the young loon no longer dove effectively and made painful and pathetic efforts to fly. Fortunately, our team captured the chick last night. A round of antibiotics and feedings, administered by Wild Instincts, might give this youngster a chance to resume its development, regain its health, and ultimately head south with its brethren. We are hoping for the best.

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I have related several stories about the adventures and misadventures about loons in the study area, and I want to update followers on how those loons are faring. As one might expect, some loons that encountered difficulties were not able to recover, while other loons beat the odds and remain healthy and vigorous.

2 August Post

Two chicks strayed from their parents’ territories to other territories on the same big lake, mingling with other families that were already raising larger and older chicks. In one case, the stray chick was apparently lost, as we have not been able to relocate the Pickerel-South chick that joined the Pickerel-West family. But the Thunder chick, which was considerably smaller than the two Boom-Hodag chicks, joined them and has gained full acceptance by the adults and its larger foster sibs, according to Kristin’s recent observations. (Today she reported that the adults are feeding the interloper!) While we do not understand why it left its parents to join another family, the Thunder chick has continued to thrive despite its dubious decision.

25 July Post

The orphan that we placed with the new pair to complete a family of two adults and two chicks has been fully accepted and is growing and being fed by its foster parents. Its acceptance is so complete, in fact, that we are having to use a simple genetic test to determine which is the biological chick and which is the orphan!

9 July Post

The territorial male that became entangled in fishing line in late June has died. We had thought that he would bounce back after Wild Instincts fed him and treated his wounds and we placed him back on his territory. Alas, he was unable to regain the weight he lost, and he did not survive for more than a few days after release. Since we used a similar protocol to treat and release another male in 2012 that survived, we are a bit puzzled by this male’s rapid demise. Obviously, the details of a loon’s injuries and its precise condition when released dictate its chances of recovery. We are sad to lose this male, who was a vigorous defender of his territory and produced three big healthy chicks during his life: two in 2009 and one in 2010.

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Life is risky for loon chicks, especially on small lakes. Our work and that of others has shown that chicks on small, acidic lakes grow more slowly and that the beta (smaller) chick is often much smaller than the alpha chick. In such cases, the alpha chick commonly pecks its sibling, which gets less food from the parents, often falls behind the family group and frequently dies. Faced with certain death if they remain near their family, many beta chicks engage in a desperate act — they leave the family, strike out across land, and try to find another lake with a breeding pair that will accept and feed them. This is not entirely foolhardy, as breeding pairs with chicks will often accept additional chicks that join their families.

Most beta chicks that choose to search for another lake are doomed, of course. It is a longshot that a chick will: 1) be able to find a nearby lake and travel to it without meeting a terrestrial predator, 2) happen to find a breeding loon pair there, and 3) gain acceptance from the pair, in the event that they have a chick or chicks of their own. Still, if you face certain death, a “Hail Mary” such as venturing to a nearby lake might make sense.

In any event, beta chicks can sometimes be found along roads or alone  in lakes without other loons, and they frequently perish there. But recently an orphaned beta chick found its way to a roadside and was picked up and carried safely to Wild Instincts where it was nursed back to health. We then estimated the size and age of the chick, matched it with the chick of one of our breeding pairs, and released it with that family. Now, two weeks later, the foster chick seems to have been fully accepted by the family and is being fed by its foster parents and accepted by its step-sib. So this seems a rare story of a desperate beta chick getting a chance with a new family that might help it reach adulthood.

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It has been a tough year for loons and fishing. One of our territorial males was hooked in the leg about 12 days ago, and the wound became infected. He was so badly impaired that he had trouble diving and “beached” himself on an island in the lake, as severely injured loons do. About a week ago, we captured him, and Wild Instincts nursed him back to health, treating the wound and feeding him to help him recover lost weight. Although a new male took over his territory, the recovering male is now back on his lake. (The lake is huge, so he will easily be able to use areas not frequented by the territorial pair.) We are hoping that he bounces back just like the male on Lower Kaubashine, who became hooked badly on a lure but was freed by Wild Instincts last year. That male too lost his territory but was strong enough to migrate, return, reclaim his old territory, and produce a chick this year. So happy endings are possible!