Myiopsitta monachus calita
The Mendoza gray-breasted parakeet (Myiopsitta monachus calita) is like the nominate race except that it is a smaller bird with a smaller beak. The breast color is more white, and the abdomen is paler. The head is a darker gray. This species is native to western Argentina in the provinces of La Rioja, Mendoza and San Luis.
Myiopsitta monachus cotorra
The Paraguayan gray-breasted parakeet (M. m. cotorra) is like calita except that the underparts are a brighter green and the abdomen is less yellow. This species is native to southeastern Bolivia and parts of Argentina and Paraguay.
An extremely rare mutation is the beautiful lutino Quaker. These birds are a pure yellow, their foreheads and underparts a grayish white. The bill is a pinkish brown, the flight feathers grayish, and the underside of the tail is a bluish green. The first of this mutation occurred in the Berlin Zoo before World War II, and they are not widely available, even in Europe.
Although not as rare as the yellow and well established in aviculture, the blue mutation is still somewhat difficult to find and is moderately expensive. Most blue Quakers descend from birds bred by M. J. Bruyneel of Steenokkerzeel in Belgium in the mid 1950’s. They are one of the most beautiful of the Quaker mutations. Their shade of blue can best be described as a powdery soft Wedgwood. The cheeks, throat and breast are a silvery blue-gray.
The top of the head and the lower rump are a beautiful deep-turquoise blue and the wings are a deep blue. The bill is a pale orange-tinged horn color. Besides their coloring, the only difference between the green and the blue Quakers is that the blue seems to be a bit smaller in size. Other than this, the blue boasts the same personality and traits that make the green Quakers so popular