This article first appeared in the June 2003 issue of the San Antonio
On a good day during migration, one can find locally four species of kingbirds: the Couch’s Kingbird (Tyrannus couchii) the Eastern Kingbird (T. tyrannus), the Western Kingbird (T. verticalis) and the Scissor-tailed Flycatcher (T. forficulata). All four related species share certain characteristics: They are medium-sized to fairly large flycatchers which forage primarily over open areas from a prominent perch. The sexes are generally similar, with sexual dimorphism strongest in the extravagantly long-tailed Scissor-tailed Flycatcher. Males perform energetic aerial courtship and territorial displays, raising their inconspicuous reddish crests when excited.
The degree of territoriality varies between species, but all will energetically harass larger birds, earning for their genus the “kingbird” moniker. Kingbirds typically form monogamous pair bonds and construct woven, cup shaped nests placed at a moderate height in a tree or on a man-made structure. Nest-building and incubation are performed primarily by the female, both sexes feed the young, and most rear but a single brood each year. All supplement their diet to varying degrees with fruit, especially in winter. Most of our kingbirds migrate at night, spending the winter in Central America and Southern Mexico.
With the possible exception of the Couch’s, the flamboyant Scissor-tailed Flycatcher is typically the first of the genus to appear each Spring, and the last to leave in the Fall. More than other kingbirds, Scissor-tails forage low to or on the ground, feeding largely upon grasshoppers and crickets. Perhaps it is this preference for orthopteran prey that allows them to linger until November, gathering each night in large communal roosts of up to hundreds of birds. This species bears the unhappy distinction of being the only kingbird seriously threatened by poaching in parts of its range, fans made from the tail feathers being used in religious ceremonies by some American Indians.
The Western Kingbird (below) lends a graceful touch of beauty to our sweltering asphalt and concrete jungles. Originally native to the arid plains, this species has readily adapted to the desert microclimate of our parking lots and busy intersections, utility poles and power lines providing convenient nesting sites and perches. A pity that their stay here is relatively brief, many having left us for their wintering grounds by the end of August.
“ Eastern Kingbird” (above) is something of a misnomer, as this bird also occurs in wetter situations across the Plains and has bred locally. Unlike other kingbirds, this species migrates by day and winters almost entirely in South America. In the Tropics it undergoes a behavioral shift, flocking like waxwings and feeding almost entirely upon fruit (like waxwings, their tail also ends in a prominent terminal band). For reasons which are unclear, Eastern Kingbirds practice extended care of their young, fledged broods remaining with the parents until the species gathers in flocks again at the onset of migration.
The exact status of the Couch’s Kingbird in this area is uncertain, although it has bred regularly as close as Castroville. Native to Central America and Mexico, scattered individuals and pairs of this species are now reported regularly year round in San Antonio. Throughout its range, this species is associated with shade trees and riparian situations. Much remains to be learned about its habits, but the large size and stout bill would seem to indicate a preference for larger insects as prey, and the ones I have seen commonly foraged higher in the air (in warm weather) than does the similarly plumaged Western Kingbird. Couch’s Kingbirds have been turning up on the local Christmas count over the past few years, the origin and eventual fate of these lingering individuals also being unknown..
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