The Canadian portion of the ecoregion is entirely in British Columbia and covers the dry Thomson Plateau squeezed between the Rocky Mountains and the Coastal Range Mountains. Abutting the Fraser Plateau to the north, it extends from just south of Wells Gray Provincial Park southward, to include the entire Okanagan Valley. In Washington, it extends south to the vicinity of Spokane.
Adjacent ecoregions: i) the ecoregion to the west in BC is the Cascade Mountains Leeward Forests (NA0507); ii) the plateau area extending off to the northwest is the Fraser Plateau and Basin Complex (NA0514); iii) the high-altitude areas to the east in both BC and WA are in the North Central Rockies Forests (NA0518); and (iv) the ecoregion to the east in all of WA is the Palouse Grasslands (NA0813).
Description of the Ecoregion
The ecoregion was described in the WWF publication “Terrestrial ecoregions of North America” (Ricketts, et al., 1999); essentially the same text can be found on-line at WWF’s site: www.worldwildlife.org. The map above is a screen shot from WWF’s Wildfinder site, now offline. There may also be additional information to be found on this ecoregion’s page at Wikipedia or at other sites.
The WWF site describes the vegetation of the ecoregion as encompassing alpine areas, forests, and grasslands. “Forest cover ranges from lodgepole pine (Pinus contorta) with quaking aspen (Populus tremuloides), white spruce (Picea glauca), and Douglas-fir (Pseudotsuga menziesii) on the plateau to Douglas-fir and pine grass at moderate mid-slope elevations. In subalpine areas, Engelmann spruce (P. engelmannii), subalpine fir (Abies lasiocarpa), and lodgepole pine grow. Valley bottoms contain ponderosa pine (P. ponderosa) with bluebunch wheatgrass (Agropyron spp.), blue grass, June-grass (Koelaria spp.) and sagebrush (Artemisia tridentata)”.
At least in Washington, the EPA’s “Okanogan Ecoregion”, as mapped at Bird Web of the Seattle Audubon Society (SAS), is essentially the same as this WWF ecoregion although the latter excludes the valley of the Okanagan River to the west which is included in the Palouse Grasslands.
Birds of the Ecoregion
Of the characteristic species (see list below), it is notable that a high proportion of the breeding species are resident year-round. A great many of these resident species only occur in the southern Okanagan Valley (southern BC and northern Washington) and not widely in the entire ecoregion.
Overall, from an avian point of view, the ecoregion seems to be very well defined at least in Canada – many bird ranges correspond nicely with this ecoregion, as might be expected since the ecoregion is warmer than surrounding high-altitude areas to the east, west, and north. In Washington, the ecoregion is not so well defined in terms of bird distribution ranges. Many bird species ranges extend directly southward along the Okanagan Valley from Canada into WA but in WA this is a different ecoregion, the Palouse Grasslands.
The Fraser Plateau ecoregion to the north is most similar, in terms of birds, to this ecoregion. It is however less rich in species and a large number of birds which are mainly resident in the Okanagan Dry Forests are summer breeders in the more northerly ecoregion.
The Seattle Audubon site includes an excellent guide to the main birding sites of their “Okanagan Ecoregion” in Washington and a detailed month by month listing of all the bird species to be expected. A small part of their ecoregion is not included in the WWF ecoregion so the list of sites and the bird list will need to be carefully interpreted.
The WWF site notes that distinctive birds of the ecoregion include: “California quail (Callipepla californica), waterfowl, blue grouse (Dendragapus obscurus) [now split off as Dusky Grouse] and long-billed curlew (Numenius americanus)”. None of these are endemic to the ecoregion.
Resources for the Ecoregion Birder
The following resources would be of value to the birder traveling to this ecoregion:
- Cannings, Russell and Richard Cannings, 2013. Bird finding in British Columbia. Greystone Books (see review at http://blog.aba.org/2014/07/birding-british-columbia.html). This guide should have good information on the BC portion of the ecoregion.
- Seattle Aubudon Society’s Bird Web is a terrific resource for Washington state (see also above).
List of Characteristic Bird Species of the Ecoregion
My list below of the “characteristic species” of the ecoregion (see an explanation on the About page) are those that are of regular occurrence and thus excludes very rare or accidental species. The species are classed as residents (r), summer breeders (s), migrants (m), wintering (w), or peripheral (x), that is, occurring in the ecoregion but only on its periphery and more characteristic of an adjacent ecoregion. The peripheral species are not included in the ecoregion total.
- Cackling Goose m
- Canada Goose r
- Trumpeter Swan w
- Tundra Swan m
- Wood Duck s
- Gadwall r
- American Wigeon r
- Mallard r
- Blue-winged Teal s
- Cinnamon Teal s
- Northern Shoveler s
- Northern Pintail s
- Green-winged Teal r
- Canvasback s
- Redhead r
- Ring-necked Duck s
- Greater Scaup m
- Lesser Scaup r
- Harlequin Duck s
- Surf Scoter m
- Bufflehead r
- Common Goldeneye r
- Barrow’s Goldeneye r
- Hooded Merganser r
- Common Merganser r
- Red-breasted Merganser m
- Ruddy Duck s
- California Quail r
- Chukar r
- Gray Partridge r
- Ring-necked Pheasant r
- Ruffed Grouse r
- Spruce Grouse r
- White-tailed Ptarmigan r
- Dusky Grouse r
- Sharp-tailed Grouse r
- Wild Turkey r
- Common Loon s
- Pied-billed Grebe r
- Horned Grebe s
- Red-necked Grebe s
- Eared Grebe s
- Western Grebe s
- Double-crested Cormorant m
- American White Pelican x
- American Bittern s
- Great Blue Heron r
- Turkey Vulture s
- Osprey s
- Bald Eagle r
- Northern Harrier r
- Sharp-shinned Hawk r
- Cooper’s Hawk r
- Northern Goshawk r
- Swainson’s Hawk s
- Red-tailed Hawk r
- Rough-legged Hawk w
- Golden Eagle r
- Virginia Rail s
- Sora s
- American Coot r
- Sandhill Crane s
- Black-necked Stilt x
- American Avocet s
- Semipalmated Plover m
- Killdeer r
- Spotted Sandpiper s
- Solitary Sandpiper s
- Greater Yellowlegs m
- Lesser Yellowlegs m
- Long-billed Curlew s
- Stilt Sandpiper m
- Dunlin m
- Baird’s Sandpiper m
- Least Sandpiper m
- Pectoral Sandpiper m
- Semipalmated Sandpiper m
- Western Sandpiper m
- Long-billed Dowitcher m
- Wilson’s Snipe r
- Wilson’s Phalarope s
- Red-necked Phalarope m
- Bonaparte’s Gull m
- Mew Gull m
- Ring-billed Gull r
- California Gull r
- Herring Gull w
- Thayer’s Gull w
- Glaucous-winged Gull w
- Glaucous Gull x
- Caspian Tern m
- Black Tern s
- Common Tern m
- Rock Pigeon r
- Band-tailed Pigeon x
- Eurasian Collared-Dove r
- Mourning Dove r
- Barn Owl x
- Flammulated Owl s
- Western Screech-Owl r
- Great Horned Owl r
- Snowy Owl w
- Northern Hawk Owl x
- Northern Pygmy-Owl r
- Burrowing Owl x
- Barred Owl r
- Great Gray Owl r
- Long-eared Owl r
- Short-eared Owl r
- Boreal Owl r
- Northern Saw-whet Owl r
- Common Nighthawk s
- Common Poorwill s
- Black Swift s
- Vaux’s Swift s
- White-throated Swift s
- Black-chinned Hummingbird s
- Rufous Hummingbird s
- Calliope Hummingbird s
- Belted Kingfisher r
- Lewis’s Woodpecker s
- Williamson’s Sapsucker s
- Red-naped Sapsucker s
- Red-breasted Sapsucker s
- Downy Woodpecker r
- Hairy Woodpecker r
- White-headed Woodpecker x
- American Three-toed Woodpecker r
- Black-backed Woodpecker r
- Northern Flicker r
- Pileated Woodpecker r
- American Kestrel r
- Merlin r
- Peregrine Falcon m
- Prairie Falcon r
- Olive-sided Flycatcher s
- Western Wood-Pewee s
- Willow Flycatcher s
- Least Flycatcher s
- Hammond’s Flycatcher s
- Gray Flycatcher s
- Dusky Flycatcher s
- Pacific-slope Flycatcher s
- Say’s Phoebe s
- Western Kingbird s
- Eastern Kingbird s
- Northern Shrike w
- Cassin’s Vireo s
- Warbling Vireo s
- Red-eyed Vireo s
- Canada Jay r
- Steller’s Jay r
- Clark’s Nutcracker r
- Black-billed Magpie r
- American Crow r
- Common Raven r
- Horned Lark r
- Tree Swallow s
- Violet-green Swallow s
- Northern Rough-winged Swallow s
- Bank Swallow s
- Cliff Swallow s
- Barn Swallow s
- Black-capped Chickadee r
- Mountain Chickadee r
- Chestnut-backed Chickadee x
- Boreal Chickadee r
- Red-breasted Nuthatch r
- White-breasted Nuthatch r
- Pygmy Nuthatch r
- Brown Creeper r
- Rock Wren s
- Canyon Wren r
- House Wren s
- Pacific Wren r
- Marsh Wren r
- Bewick’s Wren x
- American Dipper r
- Golden-crowned Kinglet r
- Ruby-crowned Kinglet s
- Western Bluebird s
- Mountain Bluebird s
- Townsend’s Solitaire r
- Veery s
- Swainson’s Thrush s
- Hermit Thrush s
- American Robin r
- Varied Thrush r
- Gray Catbird s
- Sage Thrasher s
- European Starling r
- American Pipit s
- Bohemian Waxwing w
- Cedar Waxwing r
- Lapland Longspur m
- Snow Bunting w
- Northern Waterthrush s
- Orange-crowned Warbler s
- Nashville Warbler s
- MacGillivray’s Warbler s
- Common Yellowthroat s
- American Redstart s
- Yellow Warbler s
- Yellow-rumped Warbler s
- Townsend’s Warbler s
- Wilson’s Warbler s
- Yellow-breasted Chat s
- Spotted Towhee r
- American Tree Sparrow w
- Chipping Sparrow s
- Clay-colored Sparrow s
- Brewer’s Sparrow s
- Vesper Sparrow s
- Lark Sparrow s
- Savannah Sparrow s
- Grasshopper Sparrow s
- Fox Sparrow s
- Song Sparrow r
- Lincoln’s Sparrow s
- White-throated Sparrow m
- White-crowned Sparrow s
- Golden-crowned Sparrow m
- Dark-eyed Junco r
- Western Tanager s
- Black-headed Grosbeak s
- Lazuli Bunting s
- Bobolink s
- Red-winged Blackbird r
- Western Meadowlark r
- Yellow-headed Blackbird s
- Rusty Blackbird x
- Brewer’s Blackbird r
- Brown-headed Cowbird s
- Bullock’s Oriole s
- Gray-crowned Rosy-Finch w
- Pine Grosbeak r
- House Finch r
- Cassin’s Finch r
- Red Crossbill r
- White-winged Crossbill r
- Common Redpoll w
- Pine Siskin r
- American Goldfinch r
- Evening Grosbeak r
- House Sparrow r
Resident breeders (r) 97
Summer breeders (s) 98
Migrants (m) 26
Wintering (w) 12
Peripheral (x) [not in Total] 11
TOTAL 233
DJG: 168 spp. (March 7, 2020)