Looking through my photos from Costa Rica in February 2014 there was one photograph I took of a hummingbird which was clearly labelled wrongly as Green-crowned Brilliant. Investigation led to me thinking it was probably an imm male Coppery-headed Emerald but even that didn't seem to fit exactly but then again nothing in either of the Costa Rica field guides (Stiles & Skutch and Garrigues & Dean) did either. Thankfully the Facebook page Bird ID of the World came to the rescue with it being identified as White-tailed Emerald.
My excuse is that the field guides are very misleading and my photo doesn't show the tail!
That brings my Clements World List total to 1837 with Borneo in March/April on the horizon which should add a few goodies.
White-tailed Emerald - La Paz Waterfall Gardens, Costa Rica, Feb 2014