Spring migration, 2002: Expected arrivals, surprises and no-shows
Spring migration of Whistler’s bird populations is drawing to a close. It began in early March with the arrival of several flocks of Canada Geese and came to a close, for waterfowl, with unexpected flocks of Blue-winged Teal in early June. Robins were the first to arrive in the songbird group and their cousins, the melodious Swainson’s Thrush, have been in the rearguard, arriving in early June. Many of these species are on their way north, leaving only a token few of their kind to breed in Whistler. How many species arrived this year and what is left of our winter residents?
A column in April listed the latter; populations of some are relatively stable year-round, whereas others (e.g. Song Sparrow, Spotted Towhee, Winter Wren and Varied Thrush) have been fortified by migrating brethren who don’t like our winter weather. Some of the winter birds have moved up to higher mountain slopes (dippers, juncos and Varied Thrush) but all 35 confirmed winter residents were around for at least part of the spring period. Another seven suspected winter residents also stand to be found and the Checklist of Whistler Birds suggests that about 106 migrant species should turn up during spring.
Not to be forgotten are local wanderers who hang around Squamish and Pemberton during winter, with short visits to Whistler. There are about 12 species in this grouping, mainly raptors and a couple of gulls. All told then, about 158 species are expected in the spring period using the Checklist, of which 126 (80 per cent) were actually sighted. Another 17 additional species are expected over the summer and during autumn migration.
Were there any surprises or unusual records? During the spring enumeration an out-of-season American Goldfinch (normally a very rare summer visitor), several Ruddy Ducks (rare autumn migrants) and Anna’s Hummingbirds (at several feeders) were also spotted, These three species are included on the Checklist, published in 1996. Since publication, 35 other species (all rare occurrences) have been sighted, bringing the total to 210 species plus three variants and a hybrid gull.
During the spring period the following non-listed but previously spotted birds were also seen: Greater white-fronted Goose (Nicklaus North), Red-breasted Merganser (Green Lake on two occasions), Mew Gull (Green Lake on two occasions), Caspian Tern (Green Lake), Nashville Warbler (Valley Trail, several locations), Bullock’s Oriole (Alpha Lake), and Vesper Sparrow (Green Lake walkway). There are yet more surprises.
The early June storm which blew from east to west, drenching the interior but leaving Whistler in relative rain shadow, brought some visitors over the mountain tops. At Brackendale Jim Wisnia had a colourful Lazuli Bunting in his yard, while a resident of Garibaldi Highlands had a long look at a Northern Hawk Owl – a Squamish first record.
Whistler, however, had a different group of vagabonds: Cassin’s Finch (Brio, Green Lake walkway), Veery (Wildlife Reserve, Alta Lake Park, high school), Grasshopper Sparrow (Rainbow Park), Swamp Sparrow (Green Lake walkway), and Brewer’s Sparrow (Alpha Lake Park).
The total spring count is now 141 species for year 2002. And on the first day of summer there was yet another surprising discovery, a Gray Catbird at Alpha Lake. The tentative species total now sits at 216, subject to review by Max Götz.
What were the dismal no-shows this year? Five species of waterfowl, all listed as rare; three species of rare to uncommon raptors including the Turkey Vulture; three species of upland game birds with still no luck on the White-tailed Ptarmigan despite repeated searches along the Musical Bumps; a gull, a tern, and a Rock Dove (pigeon); two species of owl including the very rare Spotted Owl; Common Nighthawk; swifts; the common Red-breasted Sapsucker and the very rare Red-naped Sapsucker; Eastern kingbird; Mountain Chickadee; both bluebird species and Redstart. Ironically Common Nighthawk and Black Swift appeared on the first day of summer; possibly the other absentees will show up over the next two months.
In late September we will draw up a list of summer residents and occasional visitors. However, for some species, including a few waterfowl, autumn migration will begin in August. For those who wish a revised list of Whistler birds, Michael Thompson (604-932-5010) will have one ready for the July 6 th monthly bird walk.
Saturday, July 6th, 7 a.m. — Bird Walk . Meet at the bottom of Lorimer Road near the entrance to the Catholic Church. Novices and newcomers welcome.
September 20-22 — Provincial Naturalists Meeting . The Whistler Naturalists are this year’s hosts for the fall meeting of the Federation of B.C. Naturalists. This three-day event will include a wide variety of talks and field trips by excellent speakers from our area and beyond.
Written by: Karl Ricker