Story by Harvey Thommasen with Photography by Mike Wigle

Winter can be a long, cold, harsh, unforgiving time on Canada’s Pacific Coast, especially in northern coastal valleys where the temperature can dip down to –15 C. Although the southern corner of the province can experience mild winters, in the north ice typically covers the rivers and steams, and snow blankets the ground.

The food that was available in the water and on the ground through the rich summer months, has suddenly becomes unavailable. The creatures that choose to spend the winters in British Columbia, rather than migrating to Central or South America, can expect to be chilled to the bone, and most face the specter of uncertain food supplies. Surviving winter, for any animal is a daily life-and-death struggle – many die.

It is no wonder, that animals that can leave do so. Many of our summer birds, our bats, and even some flying insects migrate in early fall .

Decreasing daylight hours, decreasing food supplies, and cool evening temperatures appear to be triggers for this massive exodus south. Most birds depart rather quietly.

They are here one day and gone the next. Many of the smaller species migrate only at night and that is why they are not seen flying south. But the more vocal and larger ducks, geese, and swans can be seen passing overhead, an unmistakable sign of a much greater bird migration that is under way at this time. Of the 90 or so species of birds found in the Bella Coola watershed over the summer months, approximately 55 leave before winter descends.

By the end of the September, most of the summer resident birds have left or passed through the Bella Coola Valley, and are well on their way to wintering grounds farther south.

Some birds actually choose to over-winter in the Bella Coola Valley. Many are water birds in the river estuary where they spend most of their time resting and feeding near advancing and receding tidal waters. A river estuary is an ideal place to spend a cold winter day.

Bald Eagles in snow covered trees

As the "warm" ocean waters pass over the frozen mud and vegetation, thawing takes place and food becomes available for the birds to eat. At low tides, ducks can be seen feeding on green algae (eg: Ulva spp, Enteromorpha spp, and filamentous species) scattered over the mud flats and river channels. At high tides, they graze on sedges (eg Juncus sp), Carex sp, grasses, (eg Deschampsia sp), clovers, silverweed roots, and other vascular plants.

The dabbling ducks will also snack on any insect larvae and marine invertebrates like snails (eg Braleeia acuta). After a warm, heavy winter rain, dabbling ducks like the mallard and American Widgeon will supplement their estuary diet by flying up the Valley to feed in and around flooded pastures. During cold spells, these fields become frozen over and are unavailable areas for feeding. Studies suggest that the ducks and geese minimize competition for food by having different food preferences. For example, ducks seem to have a definite preference for the roots of the wild clover plant, whereas the Canada Geese seem to prefer the silverweed roots.

Three other birds you will see in the estuary over the winter months are the kingfisher, the dipper and the great blue heron. They are welcome companions for anyone searching the waters for a steelhead or winter cutthroat.

The Bald Eagle, Glaucous-winged Gull, Herring Gull, Herring Gull, crow, and raven also search the muddy estuary shores for food over the winter months, often scavaging the last remnants of the salmon runs. Along some rivers, notably the Squamish, just north of Vancouver, hundreds of eagles gather to feast on exposed carcasses.

Trumpeter Swans are highly visible visitors that can be seen in many estuaries along the coast. British Columbia is the winter home for at least half of the world's population of Trumpeter Swans. The swans survive the winter by feeding on bottom vegetation, grazing on shore grasses, or grubbing for grass roots. They feed mainly during the daytime, but if tidal conditions are right, they will also feed at night. Favorite foods include the dense mat-like roots of the bulrush (Scirpus americanus) and arrowgrass (Triglochin maritimum).

Watching swans feed in shallow water can be quite entertaining. First, the swans rapidly paddle their feet against the soft, mucky mud to loosen the rhizome substrate. Then they dip their head and neck into the water pulling up rhizomes with the bill, leaving a depression or crater in the substrate. At times it looks like these beautiful white birds, which become darkly stained by mud, are dancing on the tidal flats, and they can provide a fascinating distraction on any winter fishing trip.