Western Kingbird

Tyrannus verticalis

Introduction

Perched with regal air on an old fence post or hawking with graceful flight low over the fields, the Western Kingbird is one of the most charismatic of Colony Farm’s and western North American birds. It is the largest of British Columbia’s flycatchers. The Western Kingbird breeds in southern portions of the western Canadian provinces, much of the western US and northern Mexico. It winters in southern Mexico, southern Florida and Central America.

Identification

Adult Male (spring/summer)

Head and nape are gray with a faint darker gray eye-line. Eye is black. Chin, throat and breast whitish-gray. Belly, flanks and undertail coverts yellow; back is olive-gray; rump and uppertail coverts black. Tail is black with white sides. Wings are dark gray with light gray edging to feathers.

Adult Female (spring/summer)

Similar to adult male.

Juvenile

Colours are more muted than adults with paler yellow belly and greenish ting above.

General Information

General:

Large flycatcher with large head, broad shoulders and heavy straight bill. Length: 20-24cm. Wing: 37-40cm. Weight: 37-46grams.

Behaviour:

Perches on exposed stumps and fence posts, hawks low over the fields for insects. The Western Kingbird is famous for its territoriality and aggression even towards raptors and other potential predators. The male has a spectacular courtship display in which he shows off his aerial prowess in a dramatic array of twists and tumbles as he descends (sometimes from over sixty feet) to an accompaniment of spirited trills.

Habitat:

Open country, dry rangeland, and riparian areas with trees and available structures for perching. Readily makes use of wire and fence posts for nesting.

Information:

Feeds primarily on insects, but also enjoys berries on occasion. Clutches vary in size according to insect populations, with the parents laying earlier, laying more eggs, and with the young growing more quickly when insects are abundant. Clutches are generally 2-7 white, creamy or pinkish with heavy blotches of brown, black or lavender eggs.

Similar species:

Cassin’s Kingbird, Couch’s Kingbird, Tropical Kingbird.

Conservation Status:

Listed as Least Concern and showing a slight increase in numbers.

Maps & Statistics

An uncommon visitor to the old fields at Colony Farm with annual occurrences of single captures.

Ageing and Sexing (Band Size: 1A,1B)

Molt Summary:

PF: HY incomplete (Sep-Nov); PB: AHY incomplete-complete (Jul-Oct)
PA: SY incomplete (Feb-May), ASY partial-incomplete

Preformative molt includes 8-10 inner gr covs, 1-3 terts (sometimes s6 as well) 1-3 middle pp (p4-p8) and often 1-2 central rects – Juvenal pp covs and most flight feathers retained

1st PA includes 1-6 ss (s4-s9 usually consecutive from inside) the outermost 2-5 pp, 0-4 inner gr covs and often 1-2 central rects

Adult PB sometimes is complete but 1-4 middle ss (s3-s6) often retained until adult PA

Adult PA includes any middle ss not replaced at PB, 0-3 inner gr covs and often 1-2 terts but usually not the central rects.

Shape of P10 & P6 in Western Kingbird by age and sex

AHY Female – Notch on p10 <10mm from tip - p6-p9 slightly notched or pointed. AHY Male – Notch on p10 > 15 mm from the tip – p6-p10 distinctly notched.

Juvenile

June - October

Juveniles lack red or orange in the crown and have brownish-washed upperparts and outer pp with blunt tips.

Some juveniles can be sexed by shape of the outer pp. (See above).

SY Alternate Plumage

April - October

ASY Alternate Plumage

April - October