Probably the most beautiful birds found in Costa Rica are Resplendent Quetzals (Pharomachrus mocinno), especially the extravagantly showy males with their long, trailing tail feathers. Resplendent Quetzals are found in montane cloud forests from southern Mexico to Panama. I observed these Resplendent Quetzals in May of 2007 at the Savegre Mountain Hotel in San Gerardo de Dota, Costa Rica, which is located at about 7000 feet (2134 m) in the Cordillera de Talamanca (Talamanca Mountains).
Male Resplendent Quetzals are a glittering iridescent green above and have a distinctive, fan-shaped head crest, a yellow bill, a row of elongated green wing coverts, black wings, a green chest, a crimson belly, a white undertail, and 25 inch (64 cm) or longer, streamer-like upper tail coverts. Like other Trogons (Family Trogonidae), Resplendent Quetzals have two front toes and two back toes on each foot, unlike other birds with their three front toes and one back toe. The Resplendent Quetzal's unusual little feet can be seen in the above photo.
Depending solely on the light and the angle of view, the jewel-like, metallic green feathers of a Resplendent Quetzal can gleam with green, blue, or golden copper iridescence.
The male Resplendent Quetzal above has some blue iridescence on his green feathers, giving him a blue-green appearance, while the male Resplendent Quetzal below appears to be heavily gilded with golden copper iridescence.
Female Resplendent Quetzals lack the fan-shaped head crest and long, streamer-like upper tail coverts of the males.
The females are iridescent green above and have a brownish head, a blackish bill, blackish wings, a green upper chest, a gray breast, a crimson belly, and a black and white-barred under tail.
Resplendent Quetzals nest in large tree cavities from March through June, and this is also the best time to observe them, especially when they are out foraging for food. During my May visit to Costa Rica, I didn't observe them nesting, but I did observe several Resplendent Quetzals visiting one of their favorite food plants, a fruiting Aguacatillo or Wild Avocado (Persea sp.) tree.
The Resplendent Quetzals swallowed the Aguacatillo fruits whole, and sometimes it took a minute or so of rhythmic gulping for them to get some of the larger fruits down. It was a bit sympathetically gag-inducing to watch at times, and although the Resplendent Quetzals never choked on their Aguacatillo fruits, they were forced to give up on a few fruits that were just too large to swallow.
After an Aguacatillo fruit is swallowed, the fruit's skin and flesh are digested, leaving just the shiny, now "clean" and still viable pit to later be regurgitated.
I observed the Resplendent Quetzals regurgitating the Aguacatillo pits before they began eating, and they did this some distance from the Aguacatillo tree, which greatly expands this plant's distribution, helping both the plant and the Aguacatillo-loving Resplendent Quetzals.