If you’ve spent time on an undeveloped lake in northern North America or Europe you’ve probably seen or heard loons. Their calls are loud and eerie, ringing out over still water and carrying far before fading amongst the trees.
Here in Vermont the Common Loons (Gavia immer) have finished nesting, the young have hatched, and the adults are teaching their young how to survive. Over the past few months they’ve flown in from their winter grounds, found nesting spots, defended them, reproduced, and will stay until the first ice begins to cover the lakes. The adults carry immature young on their backs.
When the time comes for over-wintering loons fly to the oceans. In the US there is an excellent loon tracking program that allows you to watch the movements of individual loons over the seasons.
Loons are large waterfowl with a distinct black and white pattern, reminiscent of Penguins, Auks, Razorbills, Puffins, Terns, the questionably named Imperial Shag, and a host of others. These birds are patterned white on the belly and black on the back for the same reason that Orca and other aquatic predators are; from below the white blends into the sky, and from the above the black blends into the water (or ground), providing camouflage from both prey and predators.
Loons are excellent flyer and fantastic swimmers, but have difficulty on the ground. Their large bodies are front heavy and they cannot stand upright, as a result they push themselves along the ground, sliding on their bellies. The name Loon derives from Scandinavian names for lame or clumsy, “lúinn” in Icelandic and “lam” in Swedish.
Their inability to walk means that their nests must be close to the water and that the nests must be in well protected places, usually islands or extremely wet peninsulas. As more and more lake sides are developed there is less and less nesting habitat for loons. In addition a pair of loons needs 5-20 hectares (12-50 acres) of clear undisturbed water on a lake with many small bays and nooks and a healthy fish population. Boats and swimmers can easily disturb nesting loons and studies indicate large reductions in nesting success in areas where people come into close contact with nesting loons.
There are few places that meet the nesting requirements and loons are highly territorial during nesting season.
Most of the time loons are heard, not seen, and when seen it is usually from at least a mild distance. Several weeks ago I came across a freshly dead loon on the shore of a small pond. Finding dead animals is always interesting as you have an opportunity to look at them up close and discover things you wouldn’t otherwise know.
The background of this particular loon is that it was an undersized male, blind in one eye, that (according to the banding codes) was new to the area. It fought with the male of an established nesting pair and lost the fight. A fellow from the Vermont Center for Ecosystem Studies moved the loon to a nearby lake where it stayed for several days, seemingly falling into poorer and poorer health until I found it on the beach. Upon request I collected the loon so that it could be sent to one of the research labs and an autopsy done on it.
The first thing that caught my eye was the sleek iridescence of the feathers, tending towards a blue-purple on the neck and with an oily sheen on the black back feathers, but it was the legs that fascinated me. Chicken, duck, and most other familiar birds have round legs. This makes sense, these birds must support their weight while walking, or waddling in some cases. Loons don’t walk so their legs don’t need to be especially strong side-to side. They do need to cut smoothly through the water however, and as such they are blade-like in shape presenting a narrow front to reduce drag.
The white feathers that ring the neck stand proud, rising 2-3mm above a background of short, fine, dense black feathers. Loons are cold weather birds and, like all water birds, they have dense feathers. I did not realize just how dense those feathers are though. Loon feathers feel like rich fur, not feathers, almost felt-like in texture and density.
The white speckles on the loon’s back remind me of an Escher print.
Here in Vermont loons are popular animals and there has been some good work done to protect loon habitat. As a result, loon breeding success is higher in this state than the national average. Bans on lead sinkers for fishing have helped the loon population as well as fewer individuals are swallowing the lead and getting poisoned from the metal.