both adults in general green; blue head and neck, with faint red band on throat; dull black ear coverts; red undertail coverts tipped with blue/green; olive/brown lesser wing coverts; green median wing coverts, with wide olive/brown edging; green tail with red at base. Bill dark grey with red at base. Eye ring pale grey, eye dark brown.
both adults blue of head, neck and throat darker; green lower underparts washed with blue; red undertail coverts tipped with blue.
but blue of head and neck duller; more red on throat; darker green upperparts.
pale green head, throat and breast; yellow/green undertail coverts, with varying red markings. Bill pale grey with orange/yellow at base.
Calls are high-pitched screeches and screaming notes; also some notes harsh and shrill.
Article "Blue-headed Pionus," by Susan Clubb, DVM
BirdLife International http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=1653&m=0
Internet Bird Collection http://ibc.lynxeds.com/
ML Media Collection Catalogue 138720, Blue-headed Parrot Pionus menstruus, Seeholzer, Glenn, Ucayali, Peru, Sep. 9 2008, Cornell Lab of Ornithology
Parrots: A Guide to Parrots of the World, Juniper and Parr, 1998.
Parrots of the World, Forshaw and Cooper, 1977.
Parrots of the World, Forshaw, 2006.
Parrots in Aviculture, Low, 1992.