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Autumn Migration, 2003

Early Departures and Unseasonal Interruptions

Whistler Naturalists

The autumn migration was unusual, to say the least. Up to Thanksgiving the bird counts were normal or above average on some species. But after the flood the numbers were reduced to a trickle, with many species seen rarely thereafter.

Compounding the low numbers during the period were the out migration of many of the song bird species (flycatchers, swallows, vireos and warblers) and our breeding ospreys before the onset of autumn (Sept. 22). Was their departure on advanced warning that a strange autumn was in store?

The mid-October flood, followed by the early November cold snap rudely interrupted the migration of waterfowl, and sent many of the lingering smaller birds on their way. Of the 154 autumn registered species on the Checklist of Whistler Birds only 89 (or 58 per cent) were spotted over the season.

But there were a few surprises; another six unseasonal species were seen including: a Greater white-fronted goose who hung around with a large flock of Canada geese for several weeks, Mew and Western gulls, Bohemian waxwings, a Northern shrike, and an American goldfinch. This brings the amended autumn list up to 176 species, i.e. 16 others added in 1996 to 2002, and hence a revised recovery of 54 per cent – definitely on the low side.

What were the missing species?

Of the waterfowl, including the coots, one third of the normally expected migrants failed to show, although all grebes, loons and geese species did appear. The absence of many of the duck species may be due to a murky Green Lake which, at the time of writing, is still discharging muddy water into the Green River (see Pique Nov. 28, 2003). However, the Trumpeter swans arrived on cue in early November, although all disappeared the day after the Christmas Bird Count!

Raptors and game birds, sparse as always, were seen at irregular intervals with only the Sharp-shinned hawk and Willow ptarmigan missing. The White-tailed ptarmigan, however, was spotted several times and the highlight was a flock of eight or nine in Bagel Bowl on Dec. 12 th . Rails and shorebird species were also sparse; a few days of Long-billed dowitcher sightings before the flood and coots up to the Christmas Bird Count was it, and the last coot was knocked off by an aggressive hawk before the eyes of those living at Adventure West. Large gulls flourished at the land fill, but two of the smaller species, which are migrants, Bonaparte and Ring-billed, were not seen.

Of the species inhabiting the forest there was not one audible "coo" or "hoo" from a Band-tailed pigeon and, aside from the uprising of Pygmy owls on the Christmas count, the only other owl sighting was a Barred seen by Jim Wharin in his bike rides on the trail A River Runs Through It. Woodpeckers were generally scarce, even the flicker on some days, because there was easy pine beetle fare in the infected forests to the north of Whistler. That is the going explanation for the time being. We never did spot a Red-breasted sapsucker or a Three-toed woodpecker, which are always hard to find, beetle invasion or not.

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