About Pharomachrus auriceps (Gould, 1842)
Pharomachrus auriceps, commonly called the golden-headed quetzal, has a body weight of 154–182 grams, a wingspan of 30–36 cm, and a body length of 33–36 cm, with tail plumes adding an extra 8–10 cm. Like other species in the genus Pharomachrus, it has iridescent golden-green wings and breast that can look blue in certain light. Females differ from males in coloration: their breast is duller brown, and their head is duller golden-brown, compared to the male's gold-bronze head that gives the species its name. Both sexes have short, broad bills: males have yellow bills, while females have brownish-grey bills. The species' darker green uppertail coverts extend past the tip of the tail, and this extension is longer in males than in females. Both sexes have a black undertail, though females sometimes have greyish-black undertail tips. The lower breast feathers of both sexes are bright red. Like all trogons, golden-headed quetzals have heterodactyl feet: the first and second toes point backwards, while the third and fourth point forwards. Their legs and feet are olive green or brownish. Juvenile golden-headed quetzals are brownish-black, with only a small number of iridescent green feathers on the neck and breast, and lack the adult's specialized tail coverts. Unlike other quetzal species, male golden-headed quetzals do not have a head feather crest. There are two recognized subspecies: the nominate subspecies P. a. auriceps, and P. a. hargitti, which can be told apart by longer tails and a slightly more golden color in P. a. hargitti.
Golden-headed quetzals live across Central and South America. The nominate subspecies P. a. auriceps occurs in eastern Panama's Cerro Pirre mountain, and along the Andes from southern Colombia to eastern Peru and northern Bolivia. The subspecies P. a. hargitti is only found in the Venezuelan Andes. Their most common natural habitat is humid, wet moderate-elevation montane and foothill forests, though they are also observed less often at forest edges, in clearings, and in temperate cloud forests and elfin forests. They live at elevations between 1200m and 3100m.
Outside the breeding season, golden-headed quetzals are usually solitary. During the breeding season, they are seasonally monogamous. Males attract females by establishing and singing to advertise a territory. Once paired, the two birds work together to find a nesting site and excavate a nest. Like all trogons, golden-headed quetzals are cavity-nesters: they use their bills to dig nests into decaying tree trunks, or modify existing hollows in old trees. The resulting cavities are shallow, more open, and unlined, and part of the nesting bird (either the head or tail) is usually visible from outside. Golden-headed quetzals often need to investigate many trees before finding a suitable site, because the dead tree must be soft enough to carve but not so rotten that it cannot support the nest. Little is known about the species' copulatory behaviour, as they mate discreetly. Golden-headed quetzals breed once per year between February and June. Females lay 1–2 pale blue eggs. Females handle most of the 18–19 day incubation period, except for one long daily incubation shift done by the male. Chicks fledge 25–30 days after hatching. Like all trogons, golden-headed quetzal chicks are born blind and naked. Their final juvenile plumage develops around three days before fledging: it is mostly brown and black, with visible green feathers on the nape, upper back, and throat. Brooding duties after hatching are shared equally between males and females. In the first 8–14 days after hatching, adults are present at the nest and brood 60–90% of each day; after this period, brooding frequency drops rapidly. There is no clear pattern to when males or females brood, but males consistently brood for longer periods early in the brooding period, while females brood more often towards the end of the period. It is thought that only females brood at night. Feeding duties are also equally split between the two sexes: the non-brooding adult brings food to the nest before swapping places with the brooding adult. When swapping, the incoming adult perches above the nest and gives a whinnying call to signal the brooding adult to leave. While brooding is still ongoing, adults enter the nest to feed chicks. After brooding ends, adults initially still enter the nest but spend less time inside before leaving; eight days before fledging they only lean into the nest to feed the chick before leaving; finally, 4–6 days before fledging, the chick can perch on the edge of the nest, and adults feed it while it perches there before leaving. Food brought to nestlings is usually insects, and can also include fruit. On the day of fledging, the chick perches at the front of the nest, flies away, and stays near the nest for a short time before leaving the area. Like other quetzals, but unlike many other trogons, golden-headed quetzals keep their nests clean by removing or, more commonly, swallowing all chick droppings.
