Swans

Three species of swan are regular breeders in North America. Mute swans breed in ponds and rivers in urban parks and other disturbed places, as well as more natural and wild habitats. The graceful and charismatic mute swan is familiar to most people. This species is native to Eurasia and was introduced to North America, where it has become the commonest of our swans.

The most abundant of the truly native species is the tundra or whistling swan, closely related to the Bewick's swan (Cygnus columbianus bewickii) of Eurasia. The tundra swan breeds widely on the low-arctic tundra of mainland Canada and southern Baffin Island, and mostly winters on estuaries of the Pacific and Atlantic coasts. During migration the tundra swan occurs on lakes and rivers, and sometimes in agricultural fields near water. This species usually nests beside marsh-fringed ponds or lakes. Soon after hatching, the brood of 3-5 young swans (or cygnets) accompany the parents, feeding on invertebrates during their first month or so, as well as on terrestrial grasses and sedges and aquatic vegetation.

The trumpeter swan is somewhat larger than the whistling swan. It breeds in isolated populations in Alaska, Yukon, British Columbia, and as far south as Oregon and Wyoming. This species once had a much more widespread breeding range, probably extending east to Ontario and Quebec. Unfortunately, because of agricultural conversions of its habitat and overhunting, this species was taken perilously close to extinction. However, the population of trumpeter swans has recently increased to more than 5,000 individuals, and appears to be slowly expanding. Nevertheless, the trumpeter swan remains vulnerable to population decline. The trumpeter swan winters on Pacific estuaries and offshore islands, and on a few inland lakes. Some efforts are being made to expand the range of this species through captive-breeding and release, for example, in Ontario.