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Olive-sided Flycatcher ( Contopus borealis )

By Max Gotz, Whistler Naturalists

The Olive-sided Flycatcher is most often seen perched on the tip of a large conifer from where it sings one of the most easily recognized songs found in Whistler's summer forests: a clear, loud, and snappy "quick, THREE BEER," perhaps more accurately and less alcoholically described by Sibley as: "whip, WEEDEER."

These birds prefer undisturbed forest with large trees and snags adjacent to open areas associated with lakes, ponds, meadows, bogs, and burns. The "peregrine of flycatchers" needs plenty of airspace to chase down its favourite foods (bees, wasps, and flying ants) which it captures on the wing, often returning to the perch it started from to consume its prey.

In Whistler, these birds are widespread in elevation during migration in May but singing birds in June and July are most easily found around 1,000 metres elevation and higher. Jane Lakes, Showh Lakes, and the upper Soo Valley are good areas to start listening.

The "three beer" bird belongs to the family of Tyrant Flycatchers ( Tyrannidae ), but the Olive-sided Flycatcher is more closely related to the other Wood-Peewees in the genus Contopus than the smaller Empidonax flycatchers, or the larger (and more tyrannical) Kingbirds.

Olive-sideds declined 5 per cent annually in B.C. from 1968 to 1993, and the rate of decline seems to be increasing. Deforestation of their breeding grounds, destruction of wintering habitat in South America, and an awesome and increasingly hazardous migration are probably all contributing to the astounding decline of this species. But scientists are hard pressed to provide answers, and research into the reproductive ecology, migration, and wintering ecology of this species is urgently needed.

In the meantime, B.C. naturalists are left wondering how many more years the Olive-sided Flycatcher can withstand a 1/20th population decline annually before reaching critical minimum thresholds. Could the Olive-sided Flycatcher be a species we wind up telling our grandchildren about? See one at a forest ecosystem near you while supplies last.

Upcoming Events :

April 7 - Monthly Bird Walk . Meet at the base of Lorimer Road at 7 a.m. ( please note earlier time! ). Contact Michael Thompson (932-5010) for more information.

Sightings and Memberships: NatureSpeak is prepared by the Whistler Naturalists. To become a member or to report noteworthy sightings of mammals, birds, or other species, contact Lee Edwards (905-6448; e-mail: leighe11@hotmail.com).

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