Kingdom:   Animalia
Phylum:     Chordata
Class:        Aves
Order:       Psittaciformes\
Superfamily:       Psittacoidea
Family:      Psittaculidae
Subfamily: Psittaculinae
Tribe:        Psittaculini
Genus:      Psittacula
Species:     P. derbiana
Binomial name: Psittacula derbiana
Common names: Derbyan Parakeet, Lord Derby's Parakeet, Derby’s Parakeet.

Psittacula derbiana is a monotypic parrot whose natural habitat is confined to a small pocket of moist evergreen forest in the hills of the Indian state of Arunachal Pradesh and the adjoining parts of Tibet. The species suffers from poaching for the illegal wildlife trade and fetches a high price in the black market. It is perhaps the rarest of all species of Psittacula in mainland Asia. As of the 2011 IUCN Red List of Threatened Species, its status was updated from Least Concern to Near Threatened.
Psittacula derbiana average 50 centimetres in length and are sexually dimorphic (obvious differences between the male and female). They have a mostly green plumage over their dorsal surface (i.e. from behind), black lores (region between the eyes and nostrils) and lower cheeks, a bluish-purple crown and pale yellow eyes. The throat, breast, abdomen and under-wing coverts are greyish blue to lavender. The thighs and vent area are yellowish green with blue edging on some of the feathers. The tail feathers are shades of green, some edged with blue.
The adult male and female are easily distinguished because they have different beak colours. Male birds have a red upper mandible with a yellow tip, while the lower mandible is black. The females have an all-black beak.
Immature P. derbiana are duller in colour than the adults. Juvenile birds have green crowns, orange-red upper and lower mandible (beak), and their irises are dark and do not lighten until they reach maturity between two and three years of age.
Its natural diet consists of fruits, berries, seeds and leaf buds.
The name of this bird commemorates Edward Stanley (21 April 1775 – 30 June 1851), 13th Earl of Derby a naturalist.

Photographed at Brooklands Zoo, Brooklands Drive, Pukekura Park, New Plymouth.
Male.
Male Psittacula derbiana-002.JPG

Male Psittacula derbiana.JPG  

Thanks to Wikipedia for text and information http://creativecommons.org/licenses/by-sa/3.0/