cere to the eye. The outer primary feathers of some males are tinged with blue. The upper bill of the adult male is bright red, the lower blackish brown, while the upper bill of the female is dark, almost black. The iris is yellow, varying from pale to greenish, but individuals with pink or white irides have also been noted. The skin around the eyes is orange, and the feet are grey, varying from greenish to blackish. The bill of the juvenile is red-orange, similar to that of the adult male, until two to three months after it fledges, when it changes to black, similar to that of the adult female. The immature is similar to the female. Based on the single known specimen and contemporary accounts, it is believed the male of the extinct Réunion subspecies was generally similar to that of Mauritius, but differed in being slightly larger, each wing being long and the culmen . The pink collar entirely encircled its neck, whereas it tapers out and leaves a gap at the back of the neck in the Mauritius subspecies. The Réunion subspecies also appears to have had darker lower parts. The echo parakeet is very similar to the related rose-ringed parakeet (which has been introduced to Mauritius, making confusion possible), though the green plumage of the former is darker and richer, its nape has a bluish wash, and its tail is greener above, and shorter. The female is similar to that of the rose-ringed parakeet though darker, and more emerald green. Unlike the echo parakeet, the rose-ringed parakeet does not display sexual dimorphism in beak colour. The echo parakeet is also stockier, and about 25% larger in body size and weight than the rose-ringed parakeet. The echo parakeet has comparatively shorter, broader, and more rounded wings than other Psittacula species, as well as a shorter and broader tail. Vocalisations The echo parakeet has a wide range of vocalisations, and are most vocal before roosting in the evening. They vocalise all year, but more during the breeding season. The most common vocalisation is the contact call, a low, nasal squawk sounding like "chaa-chaa, chaa-chaa" (also transliterated as "chaa-choa" or "kaah"), which is emitted singly or in a fast series, about twice a second. The flight call is very similar to the contact call. There is a higher pitched excitement or alarm call which sounds like "chee-chee-chee-chee" three