Resurgence of Evening grosbeaks highlight spring migration of 2008
By: Karl Ricker
Date: June 26, 2008
Boisterous and gregarious, Evening grosbeaks were very hard to come by anywhere in North America over the last decade. A species-of-concern designation was continually touted by the various ornithological groups that are monitoring bird populations. They disappeared altogether from the radar of our Christmas Bird Counts until the past one, when a flock of about 40 were seen in mid-December. By mid-February their piercing whistle-type of calls were a daily occurrence. Numbers of the species vastly multiplied during March and April, everywhere, at valley level in the Sea to Sky corridor. Our banner day was a flock of at least 200 within earshot of Pique’s offices at Function Junction. Even a group of 10-20 is a noisy intrusion in any backyard, which was often the case up to mid-May, when they suddenly departed for points east and north.
What brought on the “irruption” after years of very few sightings? This finch has an enormous deep and rugged bill, suggesting that good conifer cone crops may have triggered the explosion. But, our provincial ornithologist extraordinaire, Dick Cannings, says it’s the resurgence of the soft-and juicy spruce budworm cycle, which also attacks Douglas fir trees, that is responsible for the irruption, noted also in Manning Park as well as along the Mt. Baker access highway in the U.S. Cascades. At May month-end I noted large groups of the bird east of the Cascades, across the southern part of the province to as far as the Oliver-Osoyoos area in the Okanagan, in concert with the disappearance of those that were around us locally.
The Evening grosbeak is a colourful character, especially the adult males with their bright yellow “goggles” on the forehead and a body colour of rich yellow, black tail, dark brown neck, head and chest, and black wings with a white patch of secondary feathers. In a tree they puff up to robin-size, but once airborne are slimmer. Certainly they are hard to ignore by anyone out for a stroll at any time during the day when they are around.
As for the migration season on other species, certainly the late arrival of spring held up the returns or passing through of many. Other than Canada geese and Mallards, the counts on waterfowl are down, although 25 species have been seen. Exceptions are the few Wood duck in usual low numbers and a flock of 40-50 Surf scoters seen for a few days on Green Lake. For the latter the tally is usually 10 or less, but with several thousand scoters on Howe Sound this year its not surprising that the odd, modest-sized flock is on its way north through our corridor.
Numbers of raptors, rails and shorebirds (gulls and sandpipers) are also diminished and the flooding over of our deltas in mid-May certainly did not encourage the stopping-over of the lattermost. Also, the gulls are again boycotting the new compactor site in the Callaghan. Fortunately, Mike Suggate saw four large and rare-to-Whistler Caspian terns, while kayaking on Green Lake on the last day of the spring season for birds (May 31).
Woodpeckers and flycatchers are also low in number though most species have been seen. Heather Baines did find a rare Say’s phoebe at Nicklaus North, but we are still on the lookout for an Olive-sided flycatcher with its “Quick-3-Beers” call. Swallows, on the other hand, are back in their usual numbers; swifts have been spotted occasionally, but it takes a stormy gray sky to bring them into easy view. Kinglets and thrush-like birds have returned in reduced flocks, and the Mountain bluebird was reduced to a single sighting on Lorimer Road. Townsend’s solitaires continue to elude us. Late deep snow on lower mountain slopes had provided us with several days of easy spotting of Hermit thrushes stalled on our valley floor, but they are now moving upslope, along with the juncos.
Vireos and warbler counts are also down, though all expected species have shown up. Jays, crows, blackbirds and related species are in their usual numbers, added to by a few sightings of Western meadowlarks at Nicklaus North. Song sparrows are again prolific, and eight other similar species have caught our eye, the best being a very rare record of the American Tree sparrow and several sightings of Lincoln’s sparrow.
As noted in the opening paragraph, finch species have been the highlight of the spring season. Both White-winged and Red crossbills have been frequently seen, here and in the Callaghan, and Common redpolls, a northern species, were with us in March. Only the upper mountain Pine grosbeak and the rare-to-Whistler American goldfinch are missing from the usual inventory.
The observations add up to 133 species tallied of the 220 that are on our spring list; add the redpoll, new to the season, to bring it to 221. Otherwise there are no new additions to the Whistler checklist. That makes it only a 60 per cent presence ratio, down substantially from previous years when far more rare, casual and accidental sightings have occurred. The Evening grosbeak resurgence, however, makes up for the absenteeism of the others.
Birds are now in nesting season, with many out of sight. New to British Columbia is the “Breeding Atlas” project, under the directorship of Dick Cannings. Breeding atlases exist for several other provinces, and Ontario is already in the process of revising theirs. The local overall coordinator for ours is Marcia Danielson (Sea to Sky Corridor) who will also handle all breeding reports for the Squamish area (604-898-9420 or email@example.com). For Whistler and Black Tusk Village areas (2 map areas) the local coordinator is Dr. Heather Baines (604-938-1738 or firstname.lastname@example.org) ably assisted by Chris Dale (604-898-9466), who is also working in the Shadow Lake area. For the Pemberton Valley the coordinator is John Tschopp (604-894-6902). If you have nesting, or about to nest, birds in your backyard or other favourite haunt in the above-noted areas, your observations are important — even if you can’t identify the species. An “expert” will be dispatched immediately to help identify the bird(s). It’s a very big project and all citizens are encouraged to assist whenever possible.