While many residents may be familiar with the common loon (Gavia immer) of large lakes on the Kenai Peninsula, fewer may be aware that the Pacific loon (Gavia pacifica) also nests on smaller lakes on the Peninsula. In its breeding plumage the Pacific loon is in my opinion even more attractive than the common loon. The back of its neck is silvery-gray and the front of its neck black bordered on each side by striking vertical black-and-white stripes. It has a white spotted back, white breast and belly, and red eyes.
The Pacific loon weighs up to slightly over five pounds compared to as much as 13 pounds for a large common loon. The Pacific loon's smaller size allows it to avoid competition for food and nesting sites with the common loon during the breeding season. This small size and agility allows it to take off from lakes and ponds too small for the common loon. It has been reported that the Pacific loon, under windless conditions, can take off in about 150 feet while the heavier common loon under the same conditions requires about three times as much take-off distance.
Originally the Pacific loon was classified as a subspecies of the Arctic loon (Gavia arctica), but it was elevated to the level of a separate species in the 1980s. Properly speaking, the Arctic loon lives primarily in Asia and in northwestern Alaska at the tip of the Seward Peninsula and north of Kotzebue Sound.
A Pacific loon's breeding territory may include several small lakes while that of a common loon is usually one large lake. I have observed a pair of Pacific loons that used at least three and once used four small lakes during the breeding season. Pacific loons are more wary than common loons and thus more difficult to approach or photograph. They are not as vocal throughout the breeding period as common loons but do have a repertoire of unique calls, one of which sounds like a loud meowing cat.
Many of the small lakes used by breeding Pacific loons on the Kenai Peninsula do not support large sport fish but sustain populations of small three-spined sticklebacks. Diet studies have shown that sticklebacks are an important food for Pacific loons because unlike most other fish sticklebacks can tolerate low levels of oxygen and over-winter in small frozen lakes. Pacific loons also feed on aquatic insects, especially the larvae of caddis flies and dragonflies, and feed on small mollusks.
One day this summer as I stood beside a small lake a Pacific loon rapidly dropped out of the sky in a near vertical descent to land nearby and immediately began to dive for food. It dove frequently and soon disappeared behind a small peninsula. At other times after a Pacific loon detected me nearby, it suddenly disappeared and I was unable to see it again. Apparently they have the ability to remain almost completely submerged with only the tip of their bill sticking above the water, just enough to breathe.
In the summer of 2009 I joined a loon capture crew from the BioDiversity Research Institute's International Center for Loon Conservation as they attempted to capture a Pacific loon on a small lake on the refuge. Despite repeated attempts to entice the loon with recorded calls and a decoy behind a concealed submerged net, the extremely wary loon would come only so far and no closer; and our capture attempt failed.
Throughout most of the year Pacific loons are strictly marine birds spending their time off shore. They come to freshwater lakes only about three to four months out of the year to breed and then return again to the ocean. Here in Alaska that includes Prince William Sound, the lower Cook Inlet, and around Kodiak Island and the Alaska Peninsula.
There are few data on Pacific loon migration. It is believed that a large proportion of the North American Pacific loon population winters south of the United States. Interestingly, on June 5, 2004 approximately 1,070 Pacific loons were observed on a small lake in British Columbia during their northward migration -- the largest concentration of migrating Pacific loons ever observed away from the coast.
Although I thoroughly enjoy listening to and watching common loons on large lakes throughout their short breeding season on the Kenai Peninsula, I achieve a special sense of wonder when I hear, observe and sometimes am fortunate enough to photograph their smaller cousin the Pacific loon on some small unnamed lake.
Ted Bailey is a retired Kenai National Wildlife Refuge wildlife biologist who has lived on the Kenai Peninsula for over 34 years. He maintains a keen interest in the Kenai Peninsula's wildlife and natural history.
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Previous Refuge Notebook articles can be viewed on the refuge website http://kenai.fws.gov/. You can check on local birds or report your bird sighting on the Kenai National Wildlife Refuge Birding Hotline 907-262-2300.
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