The Marvelous in Nature

When Blackburnian and I were out boating yesterday evening, we came across a pair of loons who were exceptionally obliging for photographs. While we cruised slowly by in the boat, the remained on the water, looking reasonably unperturbed. At the closest we were about 20 feet away. I ran off a series of photos, trying to make the best of the opportunity in the less-than-ideal lighting, from a moving boat. A little while later, presumably the same pair flew overhead as they made their way from one end of the lake to the other. Again, very obligingly, one of the individuals circled around and flew nearly straight over the boat, the setting sun glinting off his wings and body.

More than any other, the bird that characterizes the northern landscape to me is the Common Loon, Gavia immer. It’s probably because these birds aren’t encountered during the breeding season in southern Ontario, so I only ever see them when further north, in combination with their vociferousness, which means they’re more likely to be detected than other species. In truth, the species is actually encountered further south than I may have guessed; the Atlas of the Breeding Birds of Ontario, published last winter, indicates breeding records for Common Loons as far south as the Prince Edward County area on Lake Ontario in the east, and and a spot perhaps 20 km west of where my parents live to the west. In fact, only the southern couple hundred kilometers of southern Ontario don’t record the species.

Their abundance, as mapped by the same Atlas, is much lower in southern Ontario than it is elsewhere. Highest abundance in the province is found in a few pockets in northern Ontario, particularly in northwestern Ontario. Up there, in 100 square kilometers (about 24,710 acres or 36.6 square miles) one may encounter as many as 8 birds per 25 randomly-completed point counts (the Atlas’s unit of measurement for mapping abundance). Their abundance is higher there because of the profusion of lakes and water bodies. In southern Ontario their abundance is lower, generally averaging no more than 1 or 2 birds per 25 point counts, with strongest abundance corresponding to the areas around Algonquin Provincial Park and the Frontenac Axis. The Frontenac Axis is an area of the Canadian Shield, the rocky, rugged granite landscape, that extends south to eventually join up with the Adirondacks in New York.

The loons are commonly seen here on our lake and surrounding area. We’re on the edge of the Frontenac Axis, and the landscape reflects this collision of the two regions, the granite Shield and the flatter limestone that dominates most of southern Ontario. We have the deciduous forest of the south along our road, but across the lake, in Frontenac Provincial Park, there is quite a bit of mixed forest, with a strong component of coniferous trees. The region is also characterized by many lakes; indeed, Frontenac County also has the casual name of “Land O’ Lakes”. And the lakes are full of fish.

A pair of loons needs on average about 70 hectares (173 acres) per pair to raise a family. That’s an immense amount of lake, and so usually there’s only one pair per lake. In areas where the lakes are small, a single pair may claim ownership of more than one. The reason for this is in their diet; not only finding, but being able to catch enough fish of a suitable size to feed two adults and raise a couple chicks to adulthood requires a large area to forage in. In areas where fish are abundant, the loons’ territory may be smaller; where fish are scarce the territory will be larger. The Atlas reports the range of territories, as recorded in a 1973 study, to be anywhere from 7 to 200 ha (17 to 494 acres), which is a pretty broad range. In any case, the pair of loons that we’ve observed on our lake, our neighbouring lake, and flying overhead, are most likely all the same individuals moving about between the different water bodies.

I love the loon’s crisp black-and-white pattern, punctuated with a blood-red eye. Unsurprisingly, given its appearance and haunting, lonely call, the species is a prominent figure in many cultures. Native American tribes have different stories that feature the loon, from the Chippewa tale of a loon that created the world, to those of British Columbia who believed the call of the loon predicted rain (this wouldn’t be difficult; loons call all the time, and it rains all the time in BC). The tale of how the loon got its necklace is a frequently-told one in the Ojibway and many other cultures, and I remember reading a children’s book about the story.

In modern culture, the loon is found on the Canadian one-dollar coin (called the “loonie” for this reason, not because we’re crazy to add yet another coin to what we carry around in our pockets), which was introduced in place of the paper bill in 1987. It was also found on the $20 bill of the previous Canadian currency design series (which was “birds of Canada”). The loon is the provincial bird of Ontario, and the state bird of Minnesota. And of course, the loon is the cottage country bird.

Loons are good fliers, mostly due to the stamina they have from making a living by diving for their food. Despite this, loons have exceptionally high wing-loading – a term that refers to the aerodynamics of the bird and the amount of lift created by the wing in flight (specifically, how much weight, or load, is placed per square inch of wing). A bird with low wing-loading means the wings create more than enough lift to keep the bird easily airborne. A bird with high wing-loading has just enough lift to get themselves off the ground and into the air. Like with the oceanic alcids, a loon’s wings are designed more for efficiency when diving, and the birds are so borderline when it comes to wing-loading that the loss of even a few wing feathers may be enough to render them flightless. During their spring moult prior to the breeding season they drop all of their flight feathers at the same time in order to reduce the amount of time they’re flightless (in the meantime they escape threat by diving, which is the reason they can get away with such a moult pattern – most birds moult feathers sequentially so they can still fly away from danger). Like a jet on a runway, loons need to get up speed to generate enough lift to take off, and can’t take off from land; instead they either need to face into the wind or “run” along the water’s surface as they flap to generate lift.

Loons are better divers. They use their feet to propel themselves underwater, and use their wings for additional thrush and for steering. A loon’s feet are set well back on its body to maximize efficiency underwater, much further back than the average bird, or even the average waterbird. As good as they are for swimming, this placement means a loon’s legs are nearly useless out of water. Loons have trouble walking on land because their legs aren’t centered under their center of balance. There are a handful of reports of loons making overland migrations, mostly young birds travelling from a quiet but fish-depauperate lake to a choppier or busier, but fish-full, lake a short distance away, urged on by their parents who must have decided it was too much work carrying fish back and forth to the youngsters.

Generally speaking, however, the furthest a loon will travel along land is usually the short distance from the water’s edge to its nest, which is built either on floating mats of vegetation or close to the water along the shoreline. Because of this close proximity to water, loon nests are especially vulnerable to storms and boat wakes. Nests are more frequently found on smaller lakes that are less likely to have a lot of boat traffic, particularly speed boats, but also which aren’t as prone to driving waves that build across long open expanses of water. Our lake would be perfect for them. A Common Loon’s diet is made up of small fish of many species: pike, perch, bass, sunfish and trout. Between our lake and the one next door, we’ve got all of those, in seemly good abundance. Loons prefer clear-water lakes because most of their hunting is done by sight, and our lake has excellent visibility.

This is one of my favourite shots of the pair. Loons are such majestic birds, and rarely fail to stir some emotion through either their striking plumage or haunting call. Their populations in Ontario have been fairly stable over the last 20 years, and possibly even increasing a bit in the south. Bird Studies Canada organizes a citizen science project called the Canadian Lakes Loon Survey that helps in monitoring numbers and breeding success. Botulism outbreaks periodically occur among populations causing widespread mortality, with the most recent major outbreak being in 1999-2002. Acid rain has also been determined to be a factor in breeding success, as it reduces fish population levels and also can cause heavy metals and other pollutants to leach from the surrounding landscape and build up in the food chain. There was a period where lead shot from hunters, and lead weights from anglers, was causing loon deaths from lead poisoning. The birds ingested the pellets mistakenly thinking they were pebbles, which the birds use as grit to help aid digestion, breaking down the hard bones and exoskeletons of their prey.

In the last couple of decades these lead products have been banned from a number of jurisdictions, although in many places lead shot has been banned from use in waterfowl hunting, but is still sold in the form of lead sinkers for angling. Fortunately, even in areas where there is no ban, hunters and anglers voluntarily choose non-lead alternatives. Unfortunately, the lead that was put into the environment over recent decades will remain there for a long time, ban or no ban, and will continue to poison birds for a while even after it stops being used. Recent events regarding the poisoning of seven California Condors this summer, due to lead shot in carcasses they scavenged, has given the issue national publicity, and will hopefully result in more proactive choices by sportsmen and women, and potentially further bans on the product, as well.

We’re glad that we have a pair of loons here, and that they seem to be doing well. Adult loons take off not long after finishing breeding, but young loons stay near their nesting grounds well into the fall, so we can look forward to having them around for some time yet.