Olive-sided Flycatcher

With its loud resounding song—QUICK, THREE BEERS!—and its position of prominence perched atop a large tree or snag, the Olive-sided Flycatcher is one of the most recognizable inhabitants of North America’s coniferous forests. This flycatcher undergoes one of the longest and most protracted migrations of all Nearctic migrants and the longest migration route of any flycatcher breeding in North America. It breeds in the montaine and northern forests of North America and winters winters in Central America and northern South America.

Adult Male (spring/summer)

Head is dark gray to black. White throat and central belly with contrasting dark belly sides and flanks often likened to an appearance of an unbuttoned dark vest. White undertail coverts flecked with gray. Nape, back, rump, uppertail coverts and short tail are dark gray. White tufts on sides of rump occasionally exposed when relaxed. Gray wings with indistinct pale-grayish wing-bars. Adult plumages are similar throughout the year.

Adult Female (spring/summer)

Sexes are alike in appearance. The sexes are best distinguished in the hand by wing length, which is longer in the males.

Juvenile

The plumage is similar to that of an adult, except the upperparts are more brownish, and wing featheredges are washed buff.

General:

This is a large flycatcher appearing proportionally large-headed, and short-tailed with a stout bill. Length: 18-20cm. Wing: 33cm. Weight: 32-37grams.

Behaviour:

The Olive-sided Flycatcher perches conspicuously on tops of trees from which it flies out (sallying) to snatch flying insects, and then returns to the same or another prominent perch.

Habitat:

It is common in North America’s coniferous and montane forests. It breeds in habitat along forest edges and openings, including burns; natural edges of bogs, marshes, and open water; semi-open forest; and harvested forest with some structure retained. Tall, prominent trees and snags, which serve as singing and foraging perches, and unobstructed air space for foraging, are common features of all nesting habitats.

Information:

Olive-sided Flycatchers prey almost exclusively on flying insects, especially bees. Their typical foraging behaviour of “sallying” or “yo-yo flight” has led to this species being described as “the Peregrine of flycatchers”. It is monogamous and produces 3-4 creamy white or buff eggs with ring of brownish spots on large end. Nests are open-cup structures placed at various heights above ground and well out from the trunk of a coniferous tree in a cluster of needles and twigs on a horizontal branch.

Similar species:

Greater Pewee, Eastern Wood-Pewee, Western Wood-Pewee.

Conservation Status:

Listed as Near Threatened. Has declined seriously throughout most of its range. Loss of wintering habitat may be to blame.

Capture Rates:

A rare passage migrant to Colony Farm with a single capture of the species in August.

Molt Summary:

PF: HY incomplete (Sep-Mar); PB: AHY/ASY complete (Sep-Feb); PA absent. All molting occurs on the winter grounds.
Preformative molt is eccentric with 7 – 10 inner gr covs, the outer most 5-9 pp, the innermost 3-9 ss, the outermost 0-3 pp covs, and the rects replaced. All pp and ss are replaced in less than 21% of HY/SYs.
Adult PB: is protracted with replacement of some flight feathers (usually s5-s6 and p7-p10) often being suspended over the winter.