P1120757

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.

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.

We were horrified last spring, when one of our best-known territorial males — and a super tame bird to boot — became hopelessly entangled in fishing line. This male, the long-term resident on Jersey City Flowage (“JCF”) had swallowed two lead sinkers, and monofilament line was wrapped tightly about his bill, making it impossible for him to eat. In short, the JCF male was destined to perish quickly from lead poisoning and/or lack of food. However, the folks from REGI freed him and used new technology to pluck both lead sinkers from his gut. Although he lost much of his tongue because of the fishing line, we were heartened when Linda found him in July of last year gorging himself on bullheads near his old territory (see photo below). LMG_1395 Jersey Male n Bullhead

But recovery after a brush with death was just the beginning for this bird. In order to reclaim his previous position, the male needed to regain his strength, migrate successfully to his winter quarters, survive the winter, migrate back north, and then — most challenging of all — regain possession of his former territory, which had been quickly snapped up by another male after the injury. (The new male bred successfully last year and was banded by our team.) Yesterday, Linda confirmed that the old, war-torn JCF male has negotiated all of these hurdles and settled in a breeding pair back on his old territory (see Linda’s photo below). We presume that he is also with his old mate, but she is one of the few wily adults that has managed to elude us, despite several efforts at capture. So she is still unbanded. LMG_3377 JCF Male The resilience of the JCF male is important. He is only the third adult to have been severely injured by fishing tackle, lost his territory, and recovered to reclaim it. Three data points can never be a robust sample, but we also have many cases where entanglement occurred and adult loons did not recover. In fact, we have about 9 well-documented cases of death following entanglement, which, combined with the three success stories, yields an estimate of 25% likelihood of recovery. So while the story of the JCF male’s journey from disaster to full recovery lifts our spirits, it is hard to forget that this is the exception, not the rule.

Since the inception of the study, we have known that some adult loons permit a canoeist to approach to within 5 meters without alarm, while others become uneasy and dive at a distance of 30 meters or more. Over the past several years, we have worked hard to quantify such variability in “tameness”. Our efforts are motivated by the belief that — in a region well-known for human recreation — tameness must matter. That is, it seems inconceivable that loons’ survival rate and reproductive success are not impacted by the way they respond to humans.

At first blush, I would expect loons to have higher fitness (i.e. be able to survive and breed more successfully) if their tameness reflects the lake they inhabit. That is, loons that are very tame should fare well on lakes where humans are numerous and often approach loons closely. A skittish loon on a lake with abundant human traffic would spend a great deal of time and energy avoiding humans and might have to spend more time foraging to compensate for the extra energy expenditure. A skittish individual on a busy lake might even become distracted by humans and pay too little attention to eagles, which occasionally attack adult loons and often attack chicks. On the other hand, shyness towards humans should have no impact on fitness if it occurs in a loon that occupies a remote lake.

Tameness is surprisingly vexing to measure. While it is easy to see that loons vary in approachability by canoe, it is another matter to assign a number to the degree of approachability they show. One obstacle to measurement is simply that of measuring distances accurately across water. Another is the problem that we seek to know exactly at what approach distance a loon dives to avoid a canoe; once this critical distance has been reached, the loon has left only its wake on the lake’s surface for us to measure! After numerous trials, however, Seth Yund, a Chapman student, and I have found a technique that seems to work that requires use of a highly accurate laser rangefinder — and a lot of patience. In July we began to collect measurements on each banded loon in our study population, and this work will continue into the fall and in future years. (By the way, the technique requires paddling slowly in a canoe towards a resting loon until it dives, while taking constant measurements. Since the process must only be carried out once or twice per loon, it involves very mild disturbance. We have found that loons quickly resume normal behavior after we take a tameness measurement.)

It will be some months before we begin to see if our quantification of tameness is stable and consistent enough to constitute a useful behavioral measure. At that point, we can begin to test our preliminary hypothesis that a loon’s tameness should be correlated with amount of human usage on its lake. Since we have many parent-offspring pairs in the population and follow individuals throughout their lives, we can envision asking questions about the heritability of tameness and its constancy over time. We hope that tameness will become a rewarding topic of research for us. Perhaps our ability to quantify this behavioral characteristic will permit us to foresee negative impacts that increasing human-loon contact will have on our population and help recommend ways to minimize such impacts.

Good news has been scarce this year. Black flies snuffed out first nesting attempts by virtually all breeding pairs and will reduce chick production by about 40%, compared to last year. One of the few pairs to continue incubating in defiance of the flies hatched chicks, only to lose them to infanticide when a new young male evicted the male breeder. And one of our most consistent chick producers and well-loved birds, the 19 year-old male on Jersey City Flowage, barely survived severe entanglement in fishing line that caused him to lose 20% of his body weight.

A few days ago, we received a bit of good news. The Jersey City Flowage male, after surgery and rehab work done by the folks at REGI and release near his original territory, has not only shown the capacity to feed himself normally, but has re-paired with a female hatched on Fisher Lake in Vilas County in 2010. This May-December pair seems settled at the north end of Jersey City Flowage, according to Linda Grenzer. Now, whatever judgements we are tempted to make about the age disparity in this relationship, it is nice to see the old male get himself back in shape and ready to give life another try.

Sorry for the posts on back to back days, but I wanted to report on the status of the Jersey City Flowage male, released four days ago. He is looking healthy and diving normally, it seems, as this photo by Linda Grenzer suggests. Thanks, Linda, for tracking him down!LMG_0964

He has moved about a mile in the large lake where he was released, and has skirted the territory of a pair that nests in the lake. So, while it is far too early to pronounce him out of the woods, things are looking promising. It is remarkable to observe the severe injuries from which loons can recover. Let us hope that this bird — who has both the brightest bands in the study area and the calmest disposition — can add to the short list of loons that have flirted with death following fishing entanglement, been captured and disentangled, and recovered to become territory owners again.

 

Now…I am a long-time fisherman. Since I was a young boy, I have enjoyed throwing a line in the water and imagining the lunkers waiting to strike my lure. (I think it started with McElligot’s Pool, the fantastic Dr. Seuss book that my parents read to me and my sibs.) I have spent many fruitless hours fishing — and enjoyed every minute of it. But my lifelong love of fishing has taken some bruises lately, as it has become increasingly clear that many loons in northern Wisconsin die horribly each year after entanglement in fishing line. I discussed some such incidents last year, but we have already had a recurrence of the problem this summer.

The most recent casualty is the territorial male on Jersey City Flowage. We had become rather fond of this bird, whom we banded as a chick on Swamp Lake in 1995. Year after year he and his mates have reared chicks on the Flowage, taking advantage of the abundant marshy habitat and network of islands there. He is tame, permitting us to approach closely and identify him whenever we care to. I vividly recall an occasion in 2005, when I found him foraging with his big strapping chicks. Neither he nor his juveniles cared a whit when my canoe approached them. They all foraged peacefully, oblivious to me. Here is a photo — a rather poor one — that I took Image

of the foraging family on that day.

Our team noted a month ago that the male had not returned to his territory in 2014. We were disappointed at the loss of cherished individual, but accepted that he had died over the winter or on migration or, perhaps, been evicted by another male this spring. Such are the perils faced by loons. But Marge Gibson of Raptor Education Group, Inc. notified us last week that her group had picked up a badly injured and emaciated male from a lake near Tomahawk, Wisconsin which turned out to be this male. He had swallowed two lead sinkers and, as you see, had become irrevocably entangled in the attached monofilament line.  Image

Although this bird had lost 25% of his body weight (down to 3400 g from his normal 4500 g) and was in desperate shape, Marge reports that the REGI staff were able to disentangle him, remove the lead sinkers, and get his weight back up to 3800 g with vigorous feedings. They were also able to repair his bisected tongue and restore blood flow to it. Recently, he was released near his old territory. Although it is always tricky to rehab a bird in such a weakened condition, we are allowing ourselves to hope that he will recover and will let you know what we learn of his health and territorial status. (He has lost his territory, and the new male there and his mate are nesting, according to Linda Grenzer, our tireless citizen scientist. So it will be a long road back for the injured male, even if he does return to health.)

I think that I will always enjoy the unique mixture of natural beauty, solitude, and occasional surge of adrenaline that I have enjoyed while fishing. But I will never again use lead tackle, especially now that there are many appealing alternatives. Help me spread the word about them!

One of the many triumphs of the 2013 research season was the capture and banding of the male from Mildred Lake. Although unmarked, the Mildred male was unique behaviorally. Since he took over in 2009, he was an aggressive presence in his territory. While most males get lackadaisical — or perhaps fearful — about approaching and engaging intruders, the Mildred male always did so without hesitation. He was a big, intimidating bird. Once, in 2009, he even took to the air to express himself; I will never forget him giving a ringing rendition of the territorial yodel while chasing 9 intruders in the sky far above my canoe. (This is the only time that I have ever witnessed a loon yodeling in flight.) In 2013, when, after years of fruitless incubation, he and his mate finally hatched chicks, they both tirelessly defended and fed their young until they were full grown. So he had just had a big year.

Alas, while foraging nearby on Crescent Lake, the Mildred male ran afoul of an angler.  On 17 October, the male was found there with a swallowed hook and bait inside him, still attached to a long fishing line and the fishing rod. Apparently someone left their bait and rod unattended, and the male swallowed the bait and could not free himself. As my posts from earlier this year have shown, we have a decent chance of saving a bird — even one that has swallowed a hook — if we learn about the incident quickly and can capture it soon after the event. So it is a real shame that no one was present or had the courage to report this incident and allow us to help the bird.

Our only consolation is that the Mildred male left two big strapping chicks behind, both of which are fending for themselves and not impacted by his demise. We know from genetic tests that one of these chicks is a male and the other is a female. Perhaps we will see one or both of these offspring back in three or four years’ time. That might take some of the sting out of the horrible loss of their father.

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.