Long-tailed Sylph Hummingbirds


Long-tailed Sylph (Aglaiocercus kingi)


Long-tailed Sylph (Aglaiocercus kingi) The Long-tailed Sylph (Aglaiocercus kingi) is a South American hummingbird that occurs from Venezuela south to Bolivia. It is the only sylph found on the east slopes of the Andes.

In Colombia and Ecuador, the Long-tailed Sylph is also found on the western slopes of the Andes.   

It is the most widespread member of its genus.


The Long-tailed Sylph is a short-billed, long-tailed hummingbird.

The male can easily be identified by his extremely elongated tail.  The upper side of the tail feathers  are  glittering blue green.  The male has a glittering green crown (top of the head) and throat.

The female’s tail is much shorter.  Her throat is white, speckled with green.  Her abdomen is a tawny buff.

Subspecies and Ranges:

Aglaiocercus kingi kingi – Nominate Species (Lesson, 1832) - Range: East Andes of Colombia

ID: Blue crown

  • ​​​​​​Aglaiocercus kingi margarethae (Heine, 1863) - Range: North-central and coastal Venezuela
  • Aglaiocercus kingi caudatus (Berlepsch, 1892) - Range: Western Venezuela and North Colombia
  • Aglaiocercus kingi emmae (Berlepsch, 1892) - Range: Central Andes of Northern Colombia to western Andes of South Colombia and Northwest Ecuador
    • ID: Males lack the blue throat patch. Tail is mostly blue.

ID: Blue crown. Green tipped tail feathers.

  • Aglaiocercus kingi mocoa (DeLattre and Bourcier, 1846) - Range: Central Andes of South Colombia, Ecuador and Northern Peru
  • Aglaiocercus kingi smaragdinus (Gould, 1846) - Range: East Andes of Peru and West Central BoliviaDescription

Nesting / Breeding

The male’s tail feathers are so long that they make flying cumbersome and overcoming this challenge requires a certain level of fitness and strength for the male to survive – which, in turn, attracts females to the male with the longest tail as they associate a long tail with strength.

Hummingbirds are solitary in all aspects of life other than breeding; and the male's only involvement in the reproductive process is the actual mating with the female. They neither live nor migrate in flocks; and there is no pair bond for this species. Males court females by flying in a u-shaped pattern in front of them. He will separate from the female immediately after copulation. One male may mate with several females. In all likelihood, the female will also mate with several males. The males do not participate in choosing the nest location, building the nest or raising the chicks.

The nest is a suspended ball of moss that is fastened to leafy twigs with a side entrance.The average clutch consists of one white egg, which she incubates alone, while the male defends his territory and the flowers he feeds on. The young are born blind, immobile and without any down.

The female alone protects and feeds the chicks with regurgitated food (mostly partially-digested insects since nectar is an insufficient source of protein for the growing chicks). The female pushes the food down the chicks' throats with her long bill directly into their stomachs.

As is the case with other hummingbird species, the chicks are brooded only the first week or two, and left alone even on cooler nights after about 12 days - probably due to the small nest size. The chicks leave the nest when they are about 20 days old.

Green-crowned Woodnymph (Thalurania fannyi)


Diet / Feeding

The Long-tailed Sylphsprimarily feed on nectar taken from a variety of brightly colored, scented small flowers of trees, herbs, shrubs and epiphytes. They favor flowers with the highest sugar content (often red-colored and tubular-shaped) and seek out, and aggressively protect, those areas containing flowers with high energy nectar.They use their long, extendible, straw-like tongues to retrieve the nectar while hovering with their tails cocked upward as they are licking at the nectar up to 13 times per second. Sometimes they may be seen hanging on the flower while feeding.

Many native and cultivated plants on whose flowers these birds feed heavily rely on them for pollination. The mostly tubular-shaped flowers actually exclude most bees and butterflies from feeding on them and, subsequently, from pollinating the plants.

They may also visit local hummingbird feeders for some sugar water, or drink out of bird baths or water fountains where they will either hover and sip water as it runs over the edge; or they will perch on the edge and drink - like all the other birds; however, they only remain still for a short moment.

They also take some small spiders and insects - important sources of protein particularly needed during the breeding season to ensure the proper development of their young. Insects are often caught in flight (hawking); snatched off leaves or branches, or are taken from spider webs. A nesting female can capture up to 2,000 insects a day.

Males establish feeding territories, where they aggressively chase away other males as well as large insects - such as bumblebees and hawk moths - that want to feed in their territory. They use aerial flights and intimidating displays to defend their territories.


Metabolism and Survival and Flight Adaptions - Amazing Facts


Species Research by Sibylle Johnson


Please Note: The articles or images on this page are the sole property of the authors or photographers. Please contact them directly with respect to any copyright or licensing questions. Thank you.