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.

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!

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.

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!