A deep dive with an iconic bird
The call of a loon transforms an ordinary body of water into an otherworldly landscape. In it, we hear the stewards of stillness and wilderness, but how many of us can claim to know these enchanting birds beyond their mournful cry or the coins weighing down our pockets?
James D. Paruk certainly can. His new book, Loon Lessons, represents the first detailed account of the great northern diver in thirty years (which is, coincidentally, the lifespan of one of these water birds). Paruk, an American naturalist who has spent decades studying Gavia immer, approaches his subject with a fastidiousness that never fully eclipses his sense of wonder. His reverence is infectious, and the resulting work is a rich and engrossing read.
Contrary to popular belief, common loons are not part of the Anatidae family — which includes ducks and geese — but are closely related to penguins, with a shared ancestor that dates back fifty million years. Like their tuxedo-clad cousins, they are ungainly and awkward on land — hence the adoption of the Scandinavian word for “clumsy,” lom or lumme. These northern divers were born to swim.
A heavy head and solid bones (compared with the pneumatized skeletons of most birds) allow loons to descend quickly to depths of seventy metres. In the six minutes they can stay submerged, they hunt a variety of fish and invertebrates, manipulating and swallowing their food with an agile beak and extraordinarily developed tongue (second only in its evolution to those of woodpeckers and hummingbirds). Poetically, their legs are shaped like canoe paddles, to maximize thrust and minimize drag. Joints that boast a 270-degree rotation — 90 degrees more than in other species — let their large, webbed feet grab plenty of water. Hard work will get you far, but if you’re a loon, or Michael Phelps, there are some things you were simply made for.
Still, specialists can prove poor generalists, and in addition to being lousy walkers, these black-billed birds are suboptimal flyers. They have one of the narrowest shoulder girdles of all divers. Their sternums are long, their keels shallow. A teardrop profile may be streamlined, but it “does not provide much room for breast muscle attachment.” In short, loons have less power to generate lift, so they must have a long runway for takeoff. This need can prove fatal: juveniles that wait too long to leave their natal lakes in the fall can be iced in and perish.
The “ember goose” is a social creature, and its iconic wail announces, “I am here” or asks, “Where are you?” Shorter mews, hoots, and toots are used to chat to those nearby, most often their chicks or mates. But life on the water is not always so genial. An uneasy loon might let out a tremolo (“Uh‑oh”), and an angry male will break into a shrieking, undulating yodel, which can travel up to sixteen kilometres. Individual calls are unique to individual birds and — amazingly — can be pinpointed to specific lakes. Contests for breeding spaces are intense, “and occasionally a combatant will die.” (One graduate student experienced this belligerence first-hand when his yodel playback experiment was interrupted by an agitated loon, which struck and stabbed at his canoe “to the point of damaging it.”) So much for bastions of tranquility.
Despite their struggles to get airborne, loons do make the long journey south each year, covering some thousand kilometres a day. Up and down the coasts of North America and as far south as the Yucatán Peninsula, they can be found in their flightless grey winter plumage. The notion of the boreal forest’s keening spectre vacationing “among yuccas, cacti, and palms” is almost absurd — but, as every good scientist knows, data doesn’t lie. After the Deepwater Horizon disaster in 2010, Paruk estimated that up to 11 percent of the wintering population in the northern Gulf of Mexico died from the oil spill. Those that survived flew home in the spring, to the same lakes where they were born, to continue the cycle anew.
Paruk is at his most compelling when he assumes an anecdotal mode. There’s a softness to moments like the night he babysat a bird in a motel bathtub, as he waited for a satellite transmitter to be delivered the next day. Out in the field, we’re alongside a dirt-under-his-fingernails biologist, who has no problem performing a gastric lavage to empty stomach contents for examination. Sometimes, Paruk gives in to flights of oratory, once describing natural selection as “the parsimonious reaper of extravagance.” But beyond these lofty words lie some harsh realities: chicks will kill weaker siblings for more face time with parents, and birds implanted with tracking devices will have antennae poking out through their skin.
Paruk spent 4,000 hours just observing “foot waggles,” but he does occasionally get things wrong. For instance, the loon is not Canada’s national bird (we don’t have one). But it might as well be. The loon’s familiar music speaks to a wild place within our souls; we need only listen at dusk and dawn. “I am here,” they cry, reminding us that we are, too.