Trogonidae Trogons
Version: 1.0 — Published March 4, 2020
Introduction
These generalist foragers of tropical forests often reveal their presence only by their deep whistled or chuckled calls. Once spotted, trogons can be distinguished by their hunched shoulders and long tails, and their underparts of bright yellow, red, or orange and upperparts of iridescent dark green or blue or matte cinnamon make a feast for the eyes. Sexual dimorphism in trogons grows most extreme in the quetzals, in which even the males, with their spectacularly long tail coverts, take an active role in incubating and feeding chicks in their tree-hole nest. Males sometimes aggregate loosely for days at a time early in the breeding season, but why they do so remains unclear.
Habitat
Trogons inhabit a wide variety of forest types, spanning a rainfall continuum from relatively dry pine-oak forests to humid tropical rainforest. Trogons often sit midway up trees, often well below the canopy level, in areas that afford numerous perches from which they sally while foraging.
Diet and Foraging
Trogons eat fruits, small vertebrates, and invertebrates. Studies of Neotropical trogons have shown their diet to consist mainly of fruit and insects, with some of the larger species taking vertebrate prey up to the size of small frogs and lizards. Studies of Asian trogons reveal diets that are similar to those of New World species. African trogons, however, are thought to be exclusively insectivorous, and quetzals feed almost entirely on fruit for most of the year.
Breeding
Trogons are monogamous with biparental care. All are cavity-nesting birds, usually nesting in a hole made by other species or excavating their own hole in the pithy mass of a termite nest or a rotten trunk. Trogons lay 2 to 4 eggs, from which altricial chicks hatch after an incubation period of 15 to 19 days. Males and females share in parental care, from incubation on. Brooded attentively by the parents for the first week or so, the chicks develop for 16 to 30 days before they fledge and leave the nest.
Conservation Status
Although no trogon species faces extreme threats now, all are affected by continued tropical deforestation. Those of most concern are 11 species (26%) whose small ranges make them particularly vulnerable (10 NT, 1 VU).
Systematics History
Trogonidae is the only family in the order Trogoniformes, as this is an ancient lineage with uncertain affinities to other orders. Morphological analyses generally have placed trogons in a group that includes Coraciiformes, Piciformes, and Coliiformes (Cracraft 1981, Livezey & Zusi 2001, Livezey & Zusi 2007). Recent genetic work has not refined or revised these affinities much, though it suggests less affinity with Coliiformes and places trogons sister to a clade that consists of what we here call Bucerotiformes, Piciformes, and Coraciiformes (Ericson et al. 2006a, Hackett et al. 2008, McCormack et al. 2013, Jarvis et al. 2014). The relationships within Trogonidae are generally aligned geographically. The quetzals (Pharomachrus and Euptilotis) of Central and South America are sister to the remaining trogons. Within these, the two endemic Caribbean taxa, Cuban Trogon Priotelus temnurus and Hispaniolan Trogon Temnotrogon roseigaster, are sister species, which together are sister to the remaining trogons. The African trogons (Apaloderma) are sister to the Asian trogons (Harpactes and Apalharpactes), which are in turn sister to the remaining Neotropical Trogon species (Moyle 2004).
Conservation Status
Least Concern |
65.2%
|
---|---|
Near Threatened |
10.9%
|
Vulnerable |
4.3%
|
Endangered |
0%
|
Critically Endangered |
0%
|
Extinct in the Wild |
0%
|
Extinct |
0%
|
Not Evaluated |
0%
|
Data Deficient |
0%
|
Unknown |
19.6%
|
Data provided by IUCN (2023) Red List. More information
Related families
Trogonidae is sequentially sister to a large land-bird radiation, Bucerotiformes, Coraciiformes, and Piciformes.