|A male in NW Ecuador|
|A female in NW Ecuador|
The violet-tailed sylph (Aglaiocercus coelestis) is a species of hummingbird. It is found in Colombia and Ecuador. This sylph lives in areas from 300–2,100 metres (980–6,890 ft) in elevation, though typically above 900 metres (3,000 ft) on the west slope of the Andes. A sylph is a mythological air spirit.
Males average around 7 inches (180 mm) in length, while females average around 3.8 inches (97 mm).
"...a rapid, double-sounding tez-it at 1 per sec for up to several minutes..."
"Solitary and usually low inside forest at small clumps of flowers. Hovers or occasionally clings to feed and does not gather at flowering trees."
- BirdLife International (2016). "Aglaiocercus coelestis". IUCN Red List of Threatened Species. 2016: e.T22688059A93181951. doi:10.2305/IUCN.UK.2016-3.RLTS.T22688059A93181951.en. Retrieved 12 November 2021.
- A guide to the Birds of Colombia By Steven L. Hilty, William L. Brown, p.296, Published by Princeton University Press, 1986
- Violet-tailed Sylph photos[dead link]; Article w/RangeMaps InfoNatura NatureServe[dead link]
- Violet-tailed Sylph videos on the Internet Bird Collection
- Photo-High Res; Article chandra.as.utexas.edu–"Birds of Ecuador"