Important Bird Areas

North Shore Flathead Lake

Montana

Most of the north shore of Flathead Lake, comprising the 2,000 ac Flathead Lake Waterfowl Production area and 1,600 ac of private and state land between Highway 82 and the north WPA boundary. Flathead Lake WPA includes 1.3 km of shoreline and adjacent wetland and riparian habitats along the lakeshore east of the mouth of the Flathead River, riparian habitats along 1.9 km of the river just up from its mouth, and 7.6 km of shoreline and adjacent upland habitats from the river mouth west to the townsite of Somers. The area also includes 11 parcels of land adjoining the WPA west of the river; one is owned by Burlington Northern, one was recently purchased by Montana Fish, Wildlife and Parks, one has a conservation easement in place, and 8 are currently privately owned and unprotected, although all have been identified as priorities for conservation by the Flathead Land Trust, which has spoken to all landowners and is working to find funding for such protection. Currently these parcels all have single private homes and are characterized by agricultural, wetland and limited riparian and pine forest habitat.

Ornithological Summary

The north shore of Flathead Lake and the adjoining uplands support a wide diversity of birds during all seasons, particularly during migration, when the area is heavily used by flocks of waterfowl, waterbirds and shorebirds. Overall a minimum of 229 bird species are known to occur within the IBA, and 172 of these are regular, common or abundant seasonally. There are four Bald Eagle nesting territories within the Flathead Waterfowl Production Area, which comprises >50% of the IBA. Grassland, riparian and shrubland habitats managed for waterfowl production also support nesting Northern Harriers, Short-eared Owls and Wilson's Phalaropes, along with Willow Flycatchers, Calliope and Rufous Hummingbirds, and Lazuli Bunting. Shoreline and offshore habitats are important to overwintering waterfowl and gulls, along with small concentrations of Bald Eagles.

The North shore regularly supports flocks of 10s of thousands of mixed waterfowl species during spring migration, with Northern Pintails, American Wigeon, Tundra Swan, and Canada Geese being the most common species. Offshore habitats are important during winter when up to 2000 mixed diving ducks (Redhead, Canvasback, Greater and Lesser Scaup), 2000 Mallards and 100-200 Tundra Swans overwinter here.

Over 20 species of shorebirds are known to use the area, with daily counts in the hundreds, primarily during spring migration. American Avocet, Wilson's Phalarope, Black-bellied Plover and Long-billed Dowitcher are among the species that occur annually.

Common, Caspian and Forsters Terns are all present during the breeding season, with 5-10 pairs of Common Terns confirmed as breeders in recent years. Western and Red-necked Grebes also found and suspected breeders. Dozens of Common Loons can be seen during migration. One or two Sandhill Crane pairs have nested in the past, and small numbers use the area during migration.

The site is a major staging and roosting area for gulls during spring and fall migration, with daily maximums of > 5000. Most common species include Ring-billed, California, and herring, but 7 other species have been seen. Ring-billed and California are confirmed breeders.

The Flathead WPA is closed to access during the nesting season (1 Mar - 1 Jul). This limits the amount of onsite data that has been collected describing the numbers and species using the site. But the area was found to be the single most important Canada Goose brood-rearing area in the Flathead Valley during studies conducted in the 1980s, and incidental data collected during those years also revealed the diversity of species and abundance of birds using the site during spring migration. The IBA also lies at the core of the most productive Christmas Bird Count in Montana, providing habitat for a diverse assemblage of late season migrants and winter residents.

A testament to the ornithological value of the site (expressed as both habitat for birds and as an important site for ecotourism/birding) is the long list of rare species seen here in the past 25 years. They include Parasitic Jaeger, Sabine's, Thayer's, Glaucous, Glaucous-winged, Iceland and Mew Gulls (now annual, the only place in Montana where this is the case; American Golden-Plover, Whimbrel, Pacific Loon (annual), Alder Flycatcher, Gyrfalcon, and Snowy Owl.

Conservation Issues

The primary threat to the North Shore IBA stems from residential development along the shore. In addition, invasive species on both the land and in the water remain problematic.

Ownership

see site description

Habitat

Variety as noted in habitat types.
Percentage are initial estimates --if more of lake in boundary, will need to adjust numbers.