I am going in August/Sept this year and am currently gathering info myself. Not completed it yet but here is some info on Banfff at least. Must say I have not been before so this is based on other reports/guides. I am heading from Calgary then, Banff, Jasper, Clearwater, Kamloops, Whistler, Victoria and Vancouver.
Banff Sites
Cave and Basin Marsh (2km west of Banff town) - Mallards, Green-winged Teal, and Barrow's Goldeneyes are the most common ducks. Warbling Vireos, Yellow Warblers, Common Yellowthroats, American Redstarts, Wilson's Warblers, Song Sparrows and Savannah Sparrows
Vermilion Lakes (just west of Banff town) - Osprey, Canada Geese, Common Yellowthroat, Killdeer, Song Sparrow, Mallards, American Robin, Ruby-crowned Kinglets, Black-billed Magpies
Johnston Canyon (On Highway 1A 23 km. west of Banff (just west of Castle Junction). Park at the Johnston Canyon trailhead and follow the trail up Johnston Creek 3 km. to the lower falls or 5 km. to the upper falls) Black swifts, American dipper, Winter Wren, Cordilleran Flycatchers, Townsend's and Yellow-rumped Warblers
Bow River (Banff to Lake Louise)
Hope this helps.
H