Birds Of A Feather: Mexican Bird(s) of the Month, Our Four Kings

By Dennis Taylor

Kingbirds, that is… As it turns out, Mexico hosts six different kingbird species.  However, the Western Kingbird only vacations here during the winter months before returning to its breeding grounds in the western half of the United States to breed and rear its young. And the Easter Kingbird is only a transient in Mexico as they head south to their South American wintering grounds.  Although there is some overlap in the ranges for the remaining Mexican-based kingbirds, they typically occupy different regions within Mexico. Unlike some other bird species, both male and female Kingbirds have identical plumage.

The first of these is Cassin’s Kingbird (Tyrannus vociferans).Characterized by a dark gray head and neat white throat, its light-gray chest feathers partially extend into the yellow belly typical of all the kingbirds.  Even though only about eight inches long, it lives up to its scientific moniker which translates as “vociferous tyrant”. Loud, and aggressive, they will even attack large hawks when they enter its nesting territory. Its range is confined mostly to central Mexico, extending north into parts of Arizona and New Mexico, as well as the Pacific coast north of Puerto Vallarta and Baja California. This is our local kingbird, and quite common throughout the SMA region. Like all kingbirds, it is an insectivore, so it will most often be seen perched on bare limbs, or utility poles from which it can easily fly out to capture passing insects.

The Thick-billed Kingbird (Tyrannus crassirostris) sports a large dark gray head, but with a massive bill that easily distinguishes it from other kingbirds.  Its white throat feathers extend partially down into its yellow belly. Besides being the largest of the kingbirds at ten inches in length, it is the most boisterous and pugnacious. Curving northward all the way from Mexico’s southern isthmus, its range eventually extends into the border regions with Arizona, where an ornithologist there once termed it “Arizona’s loudest bird.” It would seem, however, that this particular flycatcher is a wanderer, having been found well outside its normal range, including Texas, Nevada, Utah, Colorado, North Dakota, California, British Columbia, and even Ontario.

In contrast to the previous two kingbirds, the Tropical Kingbird (Tyrannus melancholicus) possesses a light gray head, and a full measure of bright yellow breast feathers that extend from just below its white chin feathers all the way down to its undertail coverts.  Almost all kingbird species have a bright red, orange, or yellow patch of feathers on the very top of their heads.

Under normal circumstances, they keep these feathers completely flattened and concealed beneath the gray feathers of their crown.  However, when they are excited, or defending their territory, they sometimes flash this colorful streak of feathers by parting their gray crown feathers. This handsome kingbird, about eight inches long, is commonly seen perched on bare branches or utility lines that offer it a 360-degree view of its surroundings. Aptly named, the Tropical Kingbird has the most extensive range of all the kingbirds. Found in tropical and subtropical areas of Mexico’s eastern and western coasts, its range also includes Mexico’s Yucatán. From there its range stretches southward through Central America and into South America where it can be found in tropical and subtropical regions west of the Andes all the way south to Argentina. Across this vast range, Couch’s Kingbird (Tyrannus couchii) looks nearly identical to the Tropical Kingbird.  They do have a slightly greener cast to the upper parts of their back feathers and a somewhat shorter bill, but visually, it can be very difficult to distinguish between the two based on these differences.  Typically, Couch’s Kingbirds are found in lightly wooded areas, whereas Tropical Kingbirds tend to occupy more open habitats.

The difficulty in distinguishing between these two is further complicated by the fact that the Couch’s range, which includes southern Texas, the eastern coast of Mexico and the Yucatán peninsula, overlaps with that of the Tropical Kingbird. In fact, Couch’s Kingbird, first identified in 1853 and named after Lt. Darius Couch, a naturalist and soldier from the United States who collected the first specimen, was considered to be a subspecies of the Tropical Kingbird. It was only in 1960, when ornithologists keyed in on the different calls of the two species, that the Couch was reinstated as a separate species. The distinctive difference in their calls remains the only sure way to distinguish between the two.