Trogoniformes

Trogons

(Trogonidae)

Class Aves

Order Trogoniformes

Family Trogonidae

Number of families 1

Thumbnail description
Compact, brightly colored arboreal birds with short, broad bills, long tails, and very small legs

Size
9.1–15.7 in (23–40 cm), 1.2–7.3 oz (35–210 g)

Number of genera, species
8 genera, 37 species

Habitat
Woodlands from rainforest to savannas

Conservation status
Near Threatened: 10 species

Distribution
Tropics of Africa, Asia, and New World

Evolution and systematics

Generally considered distinct enough to form their own order, trogons have traditionally been placed within the Coraciiformes near the toucans, parrots, puffbirds, cuckoos, rollers, and jacamars. The closest living relative, the mousebird, supports molecular evidence that Africa is the trogons' ancestral home, despite only three of 37 trogon species being found there today. The oldest trogoniform fossils, found in Europe, date to the Tertiary period, and it is thought that the other surviving groups split from their African relatives between 20–36 million years ago.

Divisions within the trogons remain somewhat unclear. Many authorities divide the family into African and non-African subfamilies and six genera. This system, however, groups together the New World and the Asian trogons, which are separated not only by a great geographic distance, but also by the other subfamily. An alternative solution, which seems more intuitive, proposes three subfamilies based on geography (African, Asian, and American trogons) and eight genera.

Physical characteristics

Trogons are brightly colored, compact birds with short, rounded wings, broad squared tails, and small legs and feet. Bills are short, stout, and decurved, with serrated tomia (cutting edges) and a wide gape that allows trogons to grasp and swallow prey that is large, squirming, or both.

Trogon feet are notable not only in their small size and relative weakness—the birds are unable to rotate on a perch without using their wings—but for their morphology. On each foot, two toes point forward and two point back, but unlike other zygodactyls, trogons have their first and second toes, rather than the first and fourth, directed backwards. This distinctive adaptation may help trogons cling to the sides of trees like woodpeckers, which have a similar toe arrangement.

Adult male trogons are among the most brilliantly colored of all tropical birds. Their notably soft, dense plumage is a brilliant green, blue, or violet on the upper body and chest, with yellow, orange, pink, or red underparts providing kaleidoscopic contrast. In American and African trogons, and one Asian species, the upper colors are iridescent, changing hue dramatically depending on the angle of light. Many trogons have distinctive barred or vermiculated wing panels, colored white on black in males and buff on black in females. The family's dazzling plumage is carried to an extreme in the resplendent quetzal (Pharomachrus mocinno), whose spectacular uppertail coverts are up to 25.6 in (65 cm) long.

Females are plainer, with browns and grays replacing the greens and blues of males. Female underparts, however, are often as brightly colored as those of males. Juveniles are mottled brown with white and buff spotting.

Distribution

Trogons are found in Africa, Asia, and the Americas. Most species occur in the tropics, and species richness is greatest in the Neotropics, where 25 species range from southern Arizona to Brazil. Colombia and Ecuador each have a dozen or more breeding species. This pan-tropical distribution, rare among avian families, spreads across almost 70 degrees of latitude and 11,500 ft (3,500 m) of elevation.

Habitat

Trogons are fundamentally forest birds, occasionally spreading from humid woodlands into more open habitats. Most inhabit the shady middle strata of tropical and subtropical forests. Trogons also inhabit drier habitats including thorn forests, bamboo thickets, and savanna, particularly toward the northern and southern limits of their ranges.

An ecological analysis of 25 New World species found over half utilized tropical evergreen forests, and 14 occur in at least two forest types (some use as many as four). Four or five trogon species may overlap in the tall rainforests of Asia, while the trogons of Africa range from primary forests to habitats altered by human or natural disturbances.

Behavior

Generally sedate, trogons spend most of their time perched immobile and silent. This may be in part an antipredator strategy balancing the birds' bright coloration. The main activity periods in early morning and late afternoon are punctuated with short undulatory flights after food or in defense of small territories. There is little evidence of migratory behavior among trogons, although some montane species have been noted to move to lower elevations during the summer nonbreeding season to follow fruiting events. Trogons are most often found alone or in pairs.

Accounts of visual displays are rare, but male resplendent quetzals (P. mocinno) and golden-headed quetzals (P. auriceps) both perform aerial display flights. Details on territoriality are also sparse, although strong territorial defense seems to be the norm.

Trogons' calls are typically melodious, loud, and simple. Males may repeat a monosyllabic, plaintive hoot over 100 times and give a hoarse chatter when disturbed. The calls of the quetzals and Caribbean species are slightly more complex. Songs appear to be used in territoriality and possibly mating bonding. Pair duetting has been observed in the bar-tailed trogon (Apaloderma vittatum).

Feeding ecology and diet

Fruits and insects are trogons' two main foods, although diets vary. While African species are either exclusively insectivorous or carnivorous, species in Asia and the New World eat both types of food. The quetzals, almost entirely frugivorous for most of the year, are an exception. Among the omnivores, larger species tend to eat a higher proportion of fruit. In Asia and the Americas, trogons often join mixed-species feeding flocks, and rarely follow monkey troops or army ant columns to capture disturbed insects.

Smooth-skinned caterpillars are a trogon favorite, but hairy ones are also taken infrequently, along with adult butterflies and moths. The ingestion of noxious insects may account for the unpleasant smell reported for trogon excrement and flesh. Stick insects, beetles, and other large, slow insects are also on the menu, as are the occasional small lizard, snail, or frog. Trogons eat enough fruits to be important seed dispersers: in Panama, the slaty-tailed trogon (T. massena) was found to account for 11% of all the dispersed seeds of Virola surinamensis.

Insects and fruits are obtained on the wing using a technique known alternately as "hawking," for insects, or "hovergleaning."

Trogons' deeply slotted wings allow them to stall momentarily, without losing flight control, to pluck a food item from the air or protruding stem.

Reproductive biology

Trogons pair monogamously, probably for life. Among tropical species, breeding occurs around the dry season when food items are more abundant. Spring and summer breeding is typical among species in temperate and arid areas. Pair-formation, pair-maintenance, and copulatory behavior are little understood. All trogons are cavity nesters.

Mating generally begins with a male finding a suitable nesting spot, beginning excavation, and then advertising for a mate by singing. Both members of the pair help with the construction, which may take several months. Nests are most often built in decaying tree trunks, but epiphyte root masses and occupied termitaries are also used. The violaceous trogon (T. violaceus) has alone been observed to co-occupy the nests of arboreal wasps or ants. Excavation is done mostly with the bill, and the nest cavities are either enclosed chambers accessed by an ascending tunnel, or shallow depressions that leave most of the occupying bird exposed.

Two to four eggs are laid in the unlined nest cavities. The eggs range from white to greenish or bluish in quetzals. Incubation is 16–21 days and is shared by both sexes, with the female typically taking the night shift. Chicks are fed and brooded by both parents. They are fed mostly on insects, either whole or regurgitated, and must cope with a lack of nest sanitation so pronounced that it may help discourage predators—refuse can accumulate 3.9 in (10 cm) deep in the nests of the resplendent quetzal (P. mocinno).

Conservation status

Trogons are considered relatively common, although estimating the family's overall welfare is difficult. They are especially sensitive to habitat destruction, in part because of their choosiness when it comes to selecting nesting trees. As forests are cut around the globe, it is inevitable that forest-dwelling species will decline. This is a particular concern in peninsular Malaysia, but in South America the white-tailed (T. viridis) and violaceous trogons (T. violaceus) have actually been shown to benefit from selective logging. Trogon numbers have declined near human settlements, an important consideration in ecotourism destinations such as Costa Rica, where resplendent quetzals (P. mocinno) almost single-handedly draw millions of tourist dollars every year.

Ten trogons were recognized as Lower Risk: Near Threatened on the IUCN Red List in 2002: Diard's trogon (Harpactes diardii), Whitehead's trogon (H. whiteheadi), Ward's trogon (H. wardi), Baird's trogon (T. bairdii), the Hispaniolan trogon (Temnotrogon roseigaster), the eared trogon (Euptilotis neoxenus), the scarlet-rumped trogon (H. duvaucelii), the cinnamon-rumped trogon (H. orrhophaeus), the red-naped trogon (H. kasumba), and the resplendent quetzal (P. mocinno).

Chiefly because of its great beauty, the resplendent quetzal (P. mocinno) may be the most threatened trogon of all. For

centuries, the birds' spectacular tail feathers have made them the target of hunters and collectors. Well into the twentieth century, hundreds of quetzals were exported annually from Central America for zoos, aviaries, and the decorative appeal of their tail feathers. This destructive practice likely continues to the present.

Significance to humans

Humans have long considered trogons to be special birds. Quetzalcoatl, chief god of sea, land, and air to the Aztecs and Maya of Central America, combined the body of a snake with the wings of a resplendent quetzal (P. mocinno). This bird was highly revered by both cultures, who forbade anyone but priests and royalty from possessing the tail feathers, on punishment of death—the same sentence decreed for anyone found killing a quetzal.

"Quetzal" itself comes from the Aztec word quetzalli, meaning "tail feather" but also "beautiful" or "precious." Today, the quetzal gives its name to the currency of Guatemala and its image to countless brochures and photos advertising the tropical wonders of Central and South America. The elusive quetzal remains one of the top targets for nature-oriented tourism in the region.

Species accounts

List of Species

Narina trogon

Apaloderma narina

subfamily

Apalodermatinae

taxonomy

Trogon narina Stephens, 1815, Cape Province. Six subspecies.

other common names

French; Couroucou narina; German: Narinatrogon; Spanish: Trogón de Narina.

physical characteristics

11.8–12.6 in (30–32 cm); 1.8–3.3 oz (51–95 g). Upperparts and underparts iridescent green to midbreast, abdomen and flanks crimson, undertail whitish, white bar on underwing, yellow bill.

distribution

Sub-Saharan Africa, from Sierra Leone through Congo Basin and Rift Valley to Ethiopia and eastern South Africa.

habitat

Mid-altitude rainforests, gallery forests, savanna, and woodlands.

behavior

Territorial, with non-lek male singing groups congregating during breeding season.

feeding ecology and diet

Sally-gleaning insectivore, feeding on caterpillars, orthopterans, beetles, spiders, and small reptiles.

reproductive biology

Monogamous. Breeds year-round continent-wide, but primarily in spring and summer; nests in unlined natural cavities; lays one to four eggs (most often two or three); incubates 16–21 days; fledges in 25–28 days.

conservation status

The most widespread trogon in Africa, albeit uncommon; densities up to 1.25 individuals per hectare reported.

significance to humans

None known.

Javan trogon

Apalharpactes reinwardtii

subfamily

Harpactinae

taxonomy

Trogon reinwardtii Temminck, 1822, Java. Occasionally considered conspecific with Sumatran trogon (A. mackloti), although range and appearance differ. Monotypic.

other common names

English: Blue-tailed trogon, Macklot's trogon, Reinwardt's trogon; French: Trogon de Reinwardt; German: Reinwardttrogon; Spanish: Trogón de Java.

physical characteristics

13.4 in (34 cm), weight unknown. Olive-brown head and shoulders, blue-green upperparts, yellow throat and lower breast, metallic blue tail, with three outer retrices tipped and edged in white, red bill.

distribution

West Java.

habitat

Montane evergreen forests.

behavior

Little known; probably sedentary.

feeding ecology and diet

Eats insects, including beetles, cicadas, caterpillars, grasshoppers, as well as fruit, including figs.

reproductive biology

Little known; breeding reported April through December; lays one to three eggs.

conservation status

Uncommon within restricted range.

significance to humans

None known.

Orange-breasted trogon

Harpactes oreskios

subfamily

Harpactinae

taxonomy

Harpactes oreskios Temminck, 1823, Java. Four subspecies.

other common names

English: Malayan orange-breasted trogon, mountain trogon, Stella's orange-breasted trogon, yellow-breasted trogon; French: Trogon à poitrine jaune; German: Orangebrusttrogon; Spanish; Trogón Pechinaranja.

physical characteristics

Olive-yellow head, rich chestnut upperparts, orange breast fading to bright yellow on upper and lower breast, white and black undertail, white wingpanel bars, blue orbital ring and bill.

distribution

Southern China, Malaysian Peninsula, Java, Sumatra, and northern Borneo.

habitat

Humid, lower elevation evergreen forests, open dry forest, and bamboo forest.

behavior

Perches on shorter trees in middle and upper canopy, alone and in pairs.

feeding ecology and diet

Fruits and insects including crickets, grasshoppers, beetles, ants, lizards, and various vegetable material. Occasionally feeds on ground or in mixed-species foraging flocks.

reproductive biology

Breeds January to June over range, primarily in February and March; nests in hollow stumps, often low to ground; lays one to four eggs, most often two or three. No information on brood rearing.

conservation status

Most common trogon on Malaysian Peninsula; not threatened.

significance to humans

None known.

Collared trogon

Trogon collaris

subfamily

Trogoninae

taxonomy

Trogon collaris Viellot, 1817, Cayenne. Eight subspecies.

other common names

English: Bar-tailed trogon, ray-tailed trogon, red-bellied trogon; French: Trogon rosalba; German: Jungferntrogon; Spanish: Trogón Acollarado, Sorocua Acollarado.

physical characteristics

9.8–11.4 in (25–29 cm), 1.4–2.4 oz (40–70 g). Upperparts greenish bronze, white breast band, red lower breast, blackish face and throat, yellow bill, barred black and white undertail and wingpanel.

distribution

South Mexico through Central America, Amazonian and northeast coastal South America to southeast Brazil.

habitat

Lowland tropical evergreen forest, including cloud forest, rain-forest, gallery forest, and open woodlands, especially edges.

behavior

Solitary, retiring.

feeding ecology and diet

Fruits and insects, including stick insects, beetles, and caterpillars. Often found in mixed-species flocks.

reproductive biology

Breeds January through June over range, as well as November through December, in French Guiana; nests in shallow unlined niche or cavity, occasionally termitaria; lays two or three eggs; brood rearing little known.

conservation status

Not threatened; most abundant and one of the broadest ranging of trogons.

significance to humans

None known.

Cuban trogon

Priotelus temnurus

subfamily

Trogoninae

taxonomy

Trogon temnurus Temminck, 1825, Cuba. Two subspecies.

other common names

English: Isle of Pines trogon; French: Trogon de Cuba; German: Kubatrogon; Spanish: Trogón Tocororo, Guatini.

physical characteristics

9.1–9.8 in (23–25 cm), 1.8–2.1 oz (53–60 g). Blue crown and nape, blackish face, grayish white chin, throat, and breast, red

belly, upperparts iridescent bronze-green with white spots on coverts and primaries, green-blue uppertail, distinctive scalloped retrices.

distribution

Cuba, including offshore islands.

habitat

Wet and dry tropical forests, both evergreen and deciduous, as well as pine forests and secondary forests.

behavior

Sedentary, tame.

feeding ecology and diet

Hovers to feed on flowers with tongue split at tip, also insects, fruits.

reproductive biology

Breeds May through August; nests in natural cavity or abandoned woodpecker hole; lays three or four eggs. No information on brood rearing.

conservation status

Common over range.

significance to humans

None known.

Hispaniolan trogon

Temnotrogon roseigaster

subfamily

Trogoninae

taxonomy

Trogon roseigaster Viellot, 1817, Santo Domingo. Monotypic.

other common names

English: Santo Domingo trogon; French: Trogon damoiseau; German: Rosentrogon; Spanish; Trogón de la Española, Cotorrita de Sierra, Papagayo.

physical characteristics

10.6–11.8 in (27–30) cm, 2.5 oz (74 g). Bronze-green crown and upperparts, throat, breast and upper belly gray, lower belly and undertail-coverts red, uppertail bluish green with white tips, white wingpanel bars, yellow bill.

distribution

Hispaniola.

habitat

Montane evergreen, pine, and deciduous forests, occasionally mangroves.

behavior

Little known; gather for vocal-visual mating displays.

feeding ecology and diet

Eats fruits, insects, and small lizards.

reproductive biology

Breeds March through July, nests in tree cavity or stubs, lays two eggs.

conservation status

IUCN Near Threatened species with restricted range.

significance to humans

None known.

Eared quetzal

Euptilotis neoxenus

subfamily

Trogoninae

taxonomy

Trogon neoxenus Gould, 1838, Mexico. Monotypic.

other common names

English: Eared trogon, welcome trogon; French: Trogon oreillard; German: Haabüscheltrogon; Spanish: Trogón Orejón, Quetzal Mexicano.

physical characteristics

13–14.2 in (33–36 cm), 3.6–5.2 oz (103–149 g). Upperparts and breast dark bronze-green, lower breast to undertail-coverts red, uppertail dark blue-green, wings green to slaty, primaries and three outer retrices edged in white, black head with filamentous ear-coverts and small bill.

distribution

Southern Arizona to western Mexico.

habitat

Pine woodlands, also pine-oak and pine-evergreen forests, especially canyons.

behavior

Particularly mobile for a trogon; possible seasonal altitude displacement.

feeding ecology and diet

Eats insects and fruits, favoring madroña (Arbutus arizonica).

reproductive biology

Breeds June through October, nests in live or dead tree cavities. No information on egg-laying or brood rearing.

conservation status

IUCN Near Threatened. Occurs in low densities, possibly sensitive to logging.

significance to humans

None known.

Resplendent quetzal

Pharomachrus mocinno

subfamily

Trogoninae

taxonomy

Pharomachrus mocinno de la Lave, 1832, Guatemala and Chiapas. Two subspecies.

other common names

English: Coasta Rican quetzal, northern quetzal, magnificent quetzal; French: Quetzal resplendissant; German: Quetzal; Spanish: Quetzal Guatemalteco, Quetzal Centroamericano.

physical characteristics

14.2–15.7 in (36–40 cm), with 25.6–in (65 cm) tail-streamers, 6.2–7.3 oz (180–210 g). Head, chest upperparts, and elongate greater coverts brilliant gold-green iridescing to bluish, flight feathers blackish, lower breast and undertail-coverts red, undertail white, yellow bill. Filamentous feathers give head bristling appearance.

distribution

Discontinuous through Central America, from southern Mexico to western Panama.

habitat

Cloud forests, forest edges.

behavior

Territorial. Males engage in flight displays during breeding season.

feeding ecology and diet

Sally-gleans fruit, insects, small reptiles and amphibians. Primarily frugivorous.

reproductive biology

Breeds March through June over range; nests in deep cavity in decaying tree stumps often high above ground; lays one to two eggs, incubates 17–19 days, fledges in 23–31 days. High chick mortality.

conservation status

IUCN Near Threatened species. Threatened locally by poaching and habitat disturbance.

significance to humans

Revered by Maya and Aztecs of Central America; plumes used for decoration well into the twentieth century; very popular birdwatching target.

Resources

Books

Collar, N. J. "Family Trogonidae (trogons)." In Handbook of the Birds of the World, Vol. 6. Mousebirds to Hornbills, edited by J. del Hoyo, A. Elliott, and J. Sargatal. Barcelona: Lynx Edicions, 2001.

Howell, S., and S. Webb. A Guide to the Birds of Mexico and Central America. New York: Oxford University Press, 1995.

Johnsgard, P. A. Trogons and Quetzals. Washington D.C.: Smithsonian Institution Press, 2000.

Stiles, F. G. A Guide to the Birds of Costa Rica. Ithaca: Cornell University Press, 1989.

Stotz, D. F., J. W. Fitzpatrick, T. A. Parker, and D. K. Mosovitz. Neotropical Birds: Ecology and Conservation. Chicago: University of Chicago Press, 1996.

Taylor, R. C. Trogons of the Arizona Borderlands. Tucson: Treasure Chest Publications, 1994.

Other

BirdLife International. <http://www.birdlife.net>. (10 February 2002).

Julian Smith, MS