The Long-tailed Sylph (Aglaiocercus kingi) is a species of hummingbird in the Trochilidae family. It is found in Bolivia, Colombia, Ecuador, Peru, and Venezuela. Its natural habitat is subtropical or tropical moist montane forest. Courtship strategy. The male long-tailed sylph carries characteristic elongated tail feathers. These feathers are so ridiculously long that they hinder his flight: it is difficult for him to carry such finery every day when he relies on his flying skills to survive. Female sylphs, whose tails are of a more modest size, pick out and mate with the males with the longest tail feathers. They therefore ensure that they are mating with a male who is so fit and healthy that he can live well enough to come into breeding condition even when carrying a heavy load.