Shallows

Common Loon

(Gavia immer)

Bowen birders can spot three species of loon in nearby waters. Pacific loons and the red-throated loons are occasional visitors, while the common loon is the most abundant loon species you can see fishing in Kwilákm. Common loons are winter migrants to Bowen waters, drawn from breeding populations from Saskatchewan, western Nunavut, the Northwest Territories, and west to BC’s coastal waters when forced off northern nesting lakes by winter cold and ice. Their migration to Bowen is more or less over by the end of September. During the winter, the common loon’s dramatic black-and-white breeding plumage moults to a drab grey.

Peering through winter’s fog and rain, you can recognize the common loon by its large size and habit of hunting its fishy prey by peering down into the water while swimming. Loons use their powerful hind legs to pursue prey underwater at high speed. They feed primarily on fish and, occasionally, small crabs and aquatic invertebrates. They consume most of their prey underwater and swallow it headfirst. Larger items will be taken to the surface and manipulated before swallowing. Peak foraging occurs in water less than 20 metres deep.

As the days get longer, loons prepare to head back to their northern nesting lakes. Loon migration peaks during late April to early May when loons from further south join with Bowen’s birds to return north to the deep lakes with plenty of fish where they nest and raise a family. As common loons prepare to head north, they will “tune up,” calling out with a shortened version of their wild, piercing yodel. Loons reserve the full haunting chorus until they arrive at their breeding territory.

Hear a recording of common loons calling and with young:

How are the common loons who overwinter in the Salish Sea faring? Twenty years of citizen science data, collected by volunteers with the British Columbia Coastal Waterbird Survey, shows a decline in Salish Sea common loons between 1999 and 2019. This loss of Salish Sea loons is balanced by an almost equal increase in the common loon population along BC’s outer Pacific Ocean coast.

Researchers hypothesize that species who are both long-distance migrants (common loons can travel thousands of kilometres from summer nesting lakes to winter waters) and depend upon lots of small fish to eat, will follow the availability of small fish in deciding where to settle for the winter. In recent decades, while Pacific sardine stock has increased, the abundance and availability of Pacific herring in the Salish Sea has declined. Loons may be choosing to spend the winter where they can find the most available fish.

Bird population numbers have become important indicators of both environmental success and environmental stress. The Lower Howe Sound Christmas Bird Count covers almost all islands at the mouth of the Sound, including Bowen.

The Christmas count is an opportunity for local birds. To find out more go to the Bowen Nature Club Website: https://bowennatureclub.blogspot.com

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