Comox Valley (BC014)
Courtenay, British Columbia
Altitude 0 - 200m
Comox Valley IBA, Baynes Sound IBA and Lambert Channel/Hornby Island Waters IBA share common populations of waterbirds but were established as separate IBAs because they were nominated independently. In 2013, these sites were amalgamated into the K'omoks IBA; follow this link for current information for this area.
The Comox Valley lies along the east-central coast of Vancouver Island, near the town of Courtenay. The site is bounded to the north by the Oyster River, to the south by the Trent River and Comox Harbour, to the west by the Beaufort Mountains, and to the east by the Strait of Georgia. The estuaries, backshore areas and associated lowland valley bottoms provide an extensive network of habitats. Inland valley lowlands are a mixture of agricultural areas and forested land. Low elevation forests are dominated by Douglas Fir and Western Hemlock forests. Within the valley are three urban centres, as well as a 10,000 hectare estuary. The valley has a relatively mild climate, with winter temperatures above freezing point, but generally less than 10°C on average.
The Comox Valley is noteworthy for the numbers of Pacific Trumpeter Swans that over-winter there. Based on regular surveys, the numbers of swans increased to the mid-1990s and seem to have stabilized at an over-wintering (February) population of about 2100 birds, although peak counts are over 2900 birds. Peak numbers represent over 12% of the world population of Trumpeter Swans, and over 16% of the Pacific population of this species. The swans arrive in late October and are mostly gone by early April. They feed on discarded vegetables or corn cobs, green forage between harvested corn, and seedlings of various winter cover crops, as well as native vegetation.
Waterfowl numbers reach continentally significant levels in winter. Congregations are composed of many species, most notably American Wigeon, Mallard, Northern Pintail, and Black, Surf and White-winged Scoter. Western Grebe occurred at globally significant levels most years from 1975 to 1997, but has decreased in numbers since then (numbers yet to be updated in table below). The valley and estuary are also important feeding areas for migrating Black Brant, Great Blue Heron (fannini subspecies), Glaucous-winged Gull, and Thayer's Gull (numbers yet to be updated in table below). The relative importance of the IBA to the other species listed in the table below is under review.
The population of the Comox Valley has doubled over the past 20 years. Development comes with associated threats, including runoff from sewage and suburban storm sewers, wetlands filled in, new housing developments, and disturbance from increased recreational activities. From 1992 to 2002, at least 5% of the sensitive ecosystems were lost and over 29% of modified ecosystems such as older second growth forests and seasonally flooded agricultural fields disappeared.
Potential or Ongoing Threats