Creston Valley (BC179)

Creston Valley (BC179)

Creston, British Columbia

Site Description

Creston Valley IBA is located near the town of Creston in south-central British Columbia. It is situated on the floodplain of the Kootenay River, where it enters the south end of Kootenay Lake. The area lies within one of British Columbia's few flat valleys, and is bordered by the Selkirk Mountains to the west, the Purcell Mountains to the east, Kootenay Lake to the north and the United States border to the south. Forty-five percent (45%) of the landscape is marshland, and includes the ~1,500 ha Duck Lake. The IBA includes most of the entire Creston Valley Wildlife Management Area (~7,000 ha), plus surrounding agricultural lands and wetlands within the floodplain of the Kootenay River. The valley bottom is composed of recent alluvial soils that have developed chiefly from well-sorted silty clays deposited since the last glacial period. Some local fauna are of provincial significance such as the White Sturgeon, Northern Leopard Frog and Grizzly Bear.

Birds

Significant Species - The Creston Valley IBA was designated for Tundra Swans, American Coot and waterbirds.

In the 1970s, Tundra Swan migrated through the valley regularly in globally significant numbers in the spring. Numbers decreased markedly in the 1980s, which may have been a result of change in agricultural practices in the valley (Butler et al. 1986). Significant concentrations have been detected occasionally in recent years; 1,000-1,500 Tundra Swans were counted in March 2009.

Historically, globally significant numbers of American Coot passed through annually during both spring and fall migration, and many stop to breed in the area. Significant concentrations of American Coot are still detected on one day counts, with 40-60,000 counted in fall 2012.

Globally significant numbers of waterbirds occurred regularly in the IBA in the past, with high counts ranging from 20-60,000 from 1970-1991 (Wilson 1992). Significant numbers are still detected, with 30,000 counted during spring migration in 2010. Noteworthy waterfowl include American Wigeon, which exceeded IBA thresholds several times in the 1970s, in 1990 and in 2012; and Redhead, which exceeded IBA thresholds regularly in the 1980s. Northern Pintail and scaups are also abundant in the IBA. Improved comprehensive counts of waterbirds throughout the entire IBA are needed.

Other Species of Conservation Interest - The Creston Valley IBA supports numerous species determined to be at risk by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC; wildlife species that have been assessed as at risk by COSEWIC may qualify for legal protection and recovery under Canada's Species at Risk Act). Nationally Threatened (COSEWIC) Bobolink have been seen regularly in recent years, with 15 seen in 2009. One or two Special Concern (COSEWIC) Long-billed Curlew have nested in the IBA and have been seen annually in recent years. Western Screech Owl (Endangered, COSEWIC) and Short-eared Owl (Special Concern, COSEWIC) nest and forage within the IBA. Up to four Threatened (COSEWIC) Common Nighthawk have been detected in recent summers and a nest was discovered in 2011. Threatened (COSEWIC) Barn Swallows and Bank Swallows nest in the IBA. Peregrine Falcon (Special Concern; COSEWIC) have nested just outside the IBA boundaries and hunt within the IBA.

The Creston Valley Wildlife Management Area supports one of the few breeding colonies of Western Grebes (provincially rare) in British Columbia. Up to 140 grebes have been counted during the breeding period in recent years. Approximately 1,000-1,500 were seen on Duck Lake in May 2010 during migration, which may be the largest number ever seen and recorded in the Creston Valley. Provincially rare American White Pelican can be seen in the summer months. The only breeding location of Forster's Tern in British Columbia is also found at CVWMA.

Conservation Issues

Habitat within the Creston Valley floodplain was significantly altered by the establishment of dams along the Kootenay River (e.g. Libby Dam in Montana) and dikes along both sides of the Kootenay River through the floodplain. Changes in agricultural practices over the years have also impacted waterbird habitat. For example, a decline in Tundra Swans coincided with a replacement of root crops and grains to forage (Butler et al. 1986, Wilson 1992). Improved drainage on agricultural lands reduced sheetwater ponds that are attractive to migrating waterfowl (Wilson 1992). Woody vegetation has encroached in many locations, reducing waterfowl habitat and providing suitable nesting habitat for avian predators in closer proximity to wetland areas (Annual Report 2009). Invasive plants, particularly yellow flag iris, have the potential to overtake wetlands (Annual Report 2009). Exotic fish species may be out-competing waterfowl for food in some wetland units (Annual Report 2010). A 2008 study found that some non-compliance with environmental regulations was occurring throughout the valley and water quality was being compromised by non-point source pollution, particularly in areas within close proximity to dairy farms (Davies 2008). Increasing pressures to expand motorized access and recreational use of the Wildlife Management Area could increase disturbance of species of conservation interest during the breeding season (Annual Report 2009).

Approximately 30% of this IBA is within the Creston Valley Wildlife Management Area, which was originally designated under the 1968 Creston Valley Wildlife Act and has been managed by the Creston Valley Wildlife Management Authority ever since. In June of 2012, the Minister of Forests, Lands and Natural Resource Operations announced plans to rescind the Creston Valley Wildlife Act and integrate the CVWMA with the existing 28 provincial wildlife management areas operated under the BC Wildlife Act. The Nature Conservancy of Canada owns and manages several parcels of land within the IBA for conservation purposes (e.g. Frog Bear Conservation Corridor). Ducks Unlimited Canada has been involved with the WMA since its inception and has built most of the water management infrastructure, including 30 km of dykes around the marshes and 30 water control structures, which require ongoing maintenance. Mowing and controlling water levels are done to maintain marsh habitat and productivity. Motorized access is controlled to parts of the site to limit the impacts of human use. Removal of invasive yellow flag iris is ongoing. Nest boxes have been installed for cavity nesting waterfowl, Tree Swallow and Western Screech-owl. The Creston Valley Wildlife Management Authority operates a large interpretive centre from spring through fall that provides information for visitors, educational programs for school groups, and summer children?s programs. The WMA was designated as an internationally significant wetland (Ramsar Site) in 1994 and as an Important Amphibian and Reptile Area by the Canadian Amphibian and Reptile Conservation Network, in 2005. Improved, comprehensive monitoring of IBA trigger species and species of conservation interest throughout the entire IBA is needed. There may be opportunities to improve habitat on agricultural lands, particularly during spring migration.

IBA Criteria Habitats Land Uses Potential or Ongoing Threats Conservation Status

• American Wigeon88,560 (max.)
• Tundra Swan6,000 (max.)
• Redhead9,390 (max.)
• Long-billed Dowitcher1,900 (max.)
• American Coot57,000 (max.)
• Sage Thrasher2 (max.)
• Great Blue Heron60 (max.)
• Yellow-breasted Chat1 (max.)
• Waterbirds67,000 (max.)
• Cassin's Finch70 (max.)