This species has been split from the Violaceous Trogon based on a combination of vocal, plumage and genetic differences. It is similar to the larger Green-backed Trogon, but the male has a yellow, not bluish orbital ring. Top is a male showing iridescent violet-blue head. The females (bottom) is duller with a somewhat different tail pattern and the purple iridescenct head color replaced by gray. Note also the broken whitish eyering on the female. Canon PowerShot SX60 HS.
References:
Amazonian Trogon (Trogon ramonianus), In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. retrieved from Neotropical Birds Online: https://neotropical.birds.cornell.edu/Species-Account/nb/species/viotro3
Collar, N. (2019). Violaceous Trogon (Trogon violaceus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/55701 on 5 August 2019).
Zimmer, K. J. (2010). Recognize Trogon [v.] ramonianus and T. [v.] crissalis as constituting a single species distinct from Trogon violaceus.. South American Classification Committee. http://www.museum.lsu.edu/~Remsen/SACCprop430.htm. Accessed 5 August 2019.