Christmas Bird Counts in Sea to Sky corridor net 131 species
It took the results of eight count centres, from Horseshoe Bay and Keats Island (the Lower Howe Sound CBC) to Ashcroft-Cache Creek but the 2006 Christmas Bird Census in the corridor did reach an aggregate species total typical of a single lower mainland or southern Vancouver Island count.
Yes, there are exceptions: Ladner and Victoria are duking it out at 140-150 species each for top honours in the nation each year. Nonetheless, despite the very inclement Christmas Bird Count season (Dec. 14-Jan. 5), and the cold blasts of November which preceded it, the tally was significant in quality but a little shy on quantity — especially Whistler. The following volumes and species counts were garnered at the eight centres (from south to north): Lower Howe Sound: 12,736 birds, 80 spp; Squamish: 10,202 birds, 76 spp; Whistler: 1,067 birds, 49 spp; Pemberton-Mt. Currie: 2,550 birds, 60 spp; D’Arcy-Devine: 795 birds, 54 spp; Lillooet: 3,409 birds, 58 spp; Hat Creek: 382 birds, 31 spp; and Ashcroft-Cache Creek: 1,848 birds, 43 spp. Species counts, by the way, include birds seen in count week, which for Whistler amounted to 8 of 49 tallied.
The survey covers a transect from the maritime mountain front through the entire breadth of the Coast and Cascade Mountains to the rain-shadow western edge of the Interior Plateau. There are no other transects of such calibre through a mountain system elsewhere in Canada, or Washington and Oregon, but there are two in Alaska and several in California–Nevada.
Over such a breadth a diverse array of birds is to be expected, from sea birds of the ocean environment to raptors and upland birds of the interior dry belt. Nonetheless, the following species were found in all eight counts: Great blue heron (a high of 21 at Lower Howe Sound); Bald eagle (1,625 at Squamish); Northern flicker (67 at Lower Howe Sound); Raven (268 at Lillooet); Steller’s jay (150 at Pemberton); Black-capped chickadee (276 at Squamish); Red-breasted nuthatch (51 at Lower Howe Sound); American dipper (90 at Squamish); Starling (351 at Squamish); and Song sparrow (257 at Squamish). Yes, Whistler did not have a big contribution this year on the volume of any species.
On the opposite end of the scale every count had at least one unique species, not seen elsewhere. Not unexpected there were 22 “uniques” at Lower Howe Sound (sea ducks, shore birds, but also Anna’s hummingbird, Hermit thrush and Band-tailed pigeons), 15 at Squamish (more sea ducks, Barred owl and an out-of-habitat Gray-crowned rosy finch), a surprising five at Whistler (Gadwall duck, Spruce grouse, Western gull, White-tailed ptarmigan and Three-toed woodpecker — finally!), only two at Pemberton (a flock of Tundra swans, and a Brown-headed cowbird), one at D’Arcy (Merlin), four at Lillooet (Wilson’s snipe, Morning dove, Pygmy nuthatch and Red crossbill), a single one at Hat Creek (American tree sparrow) and a lone one at Ashcroft (Sharp-tailed grouse). The compiler for Hat Creek, Ken Wright, responded by saying that he was glad to be able to contribute something new to the corridor count!
Birds not seen before at count locales were expected, as there are always a few surprises: Lower Howe Sound had only one new one, a White-breasted nuthatch, otherwise they were 10 species shy of what they usually see; Squamish had their first Greater Yellow-legs (a sandpiper), and Gray-crowned rosy finch (an upper alpine bird seen more often at the Horstman Hut!); Whistler had a lucky encounter with Spruce grouse on Blackcomb’s “Yard Sale” run (grouse of any sort are tough to find in winter, because they huddle in dense conifers for days on end); Pemberton’s new ones were the forenoted Swan, Chukar, Caissin’s finch and the Brown-headed cowbird; D’Arcy’s (the only locale to have all four tit species) was a Bushtit, Caissin’s finch, and Northern shrike; Lillooet had its first Northwestern crows, along with Horned grebe, American coot, and Marsh wren; Hat Creek registered their first American crow (where ravens and magpies rule) and a Golden-crowned kinglet; and at the far end of the chain, Ashcroft, in only their second year on the Christmas count circuit, registered 10 new additions and its most significant was the Sharp-tailed grouse.
Dispersion of inland birds to the coastal region was one of the well-broadcasted quirks for counts in British Columbia and Washington, whereas the continual disappearance of finches was another. From our corridor the following sightings of “inlanders” fit into the overall dispersal pattern as seen elsewhere in the Lower Mainland and on Vancouver Island: Pine grosbeak movement from the interior and alpine to seaward, coastal penetration of Bohemian waxwings — a species of the Great Plains (a record 1,630 were tallied at Lillooet); Common redpolls from the interior highlands to the coast; the dry belt Chukar at a Pemberton farm; Caissin’s finch reaching as far west as Mt. Currie; and a very vagrant White-breasted nuthatch at Lower Howe Sound.
On the flip side, Northwestern crows of the coast (our dominant species at Whistler) made it to Lillooet; a large flock of American robins were hanging out in Cache Creek, and Bushtits at D’Arcy is a first — usually they are at Squamish (none this year) and near the coastline of the Strait of Georgia (counted in Lower Howe Sound). The D’Arcy count also had a Common loon on Gates Lake. As for those disappearing finch species, the Pine siskin count was way down from the usual thousands; Crossbill, Purple finch and Evening grosbeak were down to a paltry few of each. Western grebes and alcids were hard to find on the coastal waters and the usual Red-throated loon did not appear in any count locally.
Species numbers in each group of birds are as follows:: loons (2 spp — usually 3 or 4); grebes (4 spp); cormorants (3 spp); herons (1 spp); swans (2 spp); geese (2 spp — Squamish with the only Greater White-fronted goose, and Canada geese counts were low everywhere); ducks (20 spp); eagles (2 spp — 3 Golden eagles at Ashcroft was the high); hawks (buteos and accipiters — 6 spp); falcons (3 spp); upland game birds (6 spp — surprisingly good); shorebirds, alcids and rails (8 spp — 10 to 12 are expected); gulls (6 spp, but no California gulls); owls (4 spp — not bad); hummers (1 spp); Kingfisher (1 spp); doves (3 spp); woodpeckers (6 spp); jays and crows (7 spp); tits (4 species); nuthatches (3 spp); creeper and wrens (3 spp, and 10 Brown creepers was an all-time high at Whistler); thrushes and kinglets (7 spp); shrike-starling-waxwing (3 spp); vireos and warblers (3 spp); sparrows (8 spp — 1 or 2 light); blackbirds (3 spp); finch and grosbeaks (10 spp).
The aggregate tally for all groups is 32,909 birds and 131 species. Not bad, considering that November’s polar blast and December’s heavy snowfalls did their best to freeze-up the duck pondage and push out any non-boreal or non-alpine species.
So, about the anticipated effects of global warming: our counts suggest that the birds handled the local cooling quite well, though numbers are down for some species, and indeed only Whistler suffered big time by the inclement polar weather. In fact, Lillooet and its waxwing invasion, Pemberton and Ashcroft had record counts. D’Arcy’s on the other hand, is the most esthetic and unique, with the knack of delivering a lot of species for so few birds seen, a trait also shown by the rural-ranchland count at Hat Creek.
Written by: Karl Ricker