The tropical kingbird (Tyrannus melancholicus) is a passerine bird in the tyrant flycatcher family Tyrannidae. It is a widespread resident breeding bird in tropical Central and South America. This bold and aggressive kingbird often hunts by hovering just below treetop level, searching for insects and sometimes berries. It is similar in appearance and habits to other kingbirds in its range with olive-gray upperparts and yellow underparts. The head is distinctly darker gray than the body plumage. It has a slightly heavier black bill and feet than other Tyrannus species. The tropical kingbird’s vocalizations are nasal and buzzing chirps, “tirrs”, and trilled whistles.
Physical Description
The tropical kingbird measures 19–21 cm (7.5–8.3 in) in length and 42–46 cm (16.5–18.1 in) in wingspan. It weighs 26–38 g (0.92–1.34 oz). The adult has pale olive-gray to olive upperparts and yellow underparts and throat. Its head is darker gray than the back. There is a concealed yellow spot in the center of the crown that only shows briefly when the bird displays. The wings and tail are brownish black. The bill is heavy, broad at the base, and black with a pale base to the lower mandible. The eyes are dark brown and the legs and feet are blackish. The sexes are similar but females tend to have browner gray upperparts and paler yellow underparts compared to the males. Juveniles are like the adult female but have yellow edges to the wing coverts.
Similar Species
The tropical kingbird can be confused with several other kingbird species within its range:
Gray kingbird
The gray kingbird (Tyrannus dominicensis) is a very close relative of the tropical kingbird, and where their ranges overlap they can be very difficult to distinguish. The gray kingbird has a more northern distribution, being abundant in the Caribbean, southeastern United States, and the Pacific coast of Mexico. It is slightly smaller than the tropical kingbird. The gray kingbird has a darker head that contrasts more with the pale gray back. The most reliable distinction is the call, a high thin “tseep” in the gray kingbird.
Fork-tailed flycatcher
The fork-tailed flycatcher (Tyrannus savana) appears dark gray and white due to its blackish mantle contrasting with white underparts. It has very long tail streamers. It has more aerial foraging habits than the tropical kingbird.
Scissor-tailed flycatcher
The scissor-tailed flycatcher (Tyrannus forficatus) occurs in open grassy or agricultural areas. As its name suggests, it has extremely long, scissor-like tail feathers. It lacks the bold head pattern of the tropical kingbird.
Eastern kingbird
The eastern kingbird (Tyrannus tyrannus) breeds in North America and overwinters in South America where it co-occurs with tropical kingbirds. The eastern kingbird is darker olive-gray on the head and back contrasting with a white throat and pale gray breast.
Geographic Range and Habitat
The tropical kingbird has an extensive range across Central and South America. Its breeding range stretches from southern Mexico south through Central America into most of South America, east of the Andes, as far south as northern Argentina and southern Brazil. It generally occurs up to 1000 m elevation but has been recorded up to 1600 m in Costa Rica and 3000 m in Ecuador.
The tropical kingbird inhabits open forests, woodland edges, plantations, parks, and gardens. It requires scattered trees or other suitable perches for hunting insects on the wing. It often occurs near rivers and streams. It typically avoids denser rainforest and the higher elevations of mountain ranges.
Behavior and Diet
The tropical kingbird is an active and aggressive bird, constantly perching upright and observing its surroundings. It frequently sallies out to snap up insects in flight, sometimes hovering briefly to search for prey. It also seizes prey like bees, wasps, and butterflies from branches and vegetation. It sometimes eats berries and fruits.
These kingbirds are territorial and chase away potential predators and competitors from their territory, including larger birds like crows and hawks. They may mob perched raptors with loud calls, dive-bombing attacks, and defecating on the predator. They also have fierce conflicts with other kingbirds over territorial boundaries.
Tropical kingbirds typically sit high in dead trees to survey their territory, defending an area 100-200 m in diameter. They rest at night by ascending to the top of a tree, puffing out their feathers, and closing their eyes while perching upright.
Vocalizations
The tropical kingbird’s calls includes nasal and buzzing chirps like “tirr” and “zeet”, sometimes preceded by a harsher rattling note. It gives a trilled whistle “prrr-it-it-it” when displaying. It makes a sputtering “pit-pit” sound when mobbing predators or competing with other kingbirds. It has a piercing alarmed call “tseer” when warning of hawks and other threats.
Reproduction
Tropical kingbirds breed at the start of the rainy season, which varies across its wide range. Courtship feeding helps form the pair bond, where the male passes food items to the female. The nest is a bulky cup constructed from twigs, leaves, grass, lichens, and bound with spider webs. It is built 1.5 to 12 m high in a tree or bush. The female incubates the typical clutch of two or three eggs for 15-18 days. Both parents feed the chicks with insects. The young fledge about 18-21 days after hatching. These kingbirds raise one to two broods per season.
Conservation Status
The tropical kingbird has an extremely large range estimated at 8.7 million square kilometers. The global population has not been quantified but is believed to be very large based on its widespread distribution. The species is described as common in most of its range. The population is stable with no major threats known. The tropical kingbird is classified as Least Concern on the IUCN Red List.
Similar Families
The tropical kingbird and other Tyrannidae tyrant flycatchers share the family Tyrannidae with over 400 species worldwide. Some other families with similar ecological niches and outward appearances are:
Laniidae – Shrikes
Shrikes occur on most continents worldwide and occupy the same predatory niche as tyrant flycatchers, eating insects, other arthropods, small vertebrates, and some fruit. They have stout hooked bills and often impale prey on thorns or barbed wire.
Vireonidae – Vireos
New World vireos occupy forest and woodland in the Americas. They glean insects from foliage in a similar way to tyrant flycatchers but have slightly stouter bills and duller coloration.
Monarchidae – Monarch Flycatchers
This family occurs in the Australasia and Indo-Pacific regions. They fill the predatory flycatcher niche ecologically but are not closely related.
Campephagidae – Cuckoo-shrikes
Found in Africa, Asia, and Australasia, these medium-sized flycatchers exhibit similarities in diet and behavior but are classified in a different order.
Conclusion
In summary, the tropical kingbird is most similar to other kingbirds in the genus Tyrannus such as the gray kingbird and eastern kingbird. It shares the family Tyrannidae with a diverse assemblage of American flycatchers that occupy comparable ecological niches. Other families around the world display some analogies like the shrikes, vireos, monarch flycatchers, and cuckoo-shrikes that serve as aggressive aerial insectivores. But they have arisen from separate evolutionary lineages. With no close living relatives outside Tyrannidae, the tropical kingbird remains in a unique position among New World flycatchers.