The Alexandrine Parakeet/Parrot, named after Alexander the Great who took many of them from India to Europe, is similar to a large Ring-necked Parakeet. It is about a third larger (58-60 cm length depending on subspecies) than the Ringneck (some 40-42 cm), has an over-sized, all-red bill with light orange tip and it also has a dark pink/red "shoulder" patch. The male has a wider neck ring.
The female and juvenile Alexandrine Parakeets do not have the black/pink ringed neck and are duller in colour. Even as a fledgling, the Alexandrine has the red "shoulder" patch on its wing.
The long tail, as long as the head and body -- longer on adult males than on females.
Hobbies include photography . . .
. . . and stealing fruit.
This is one of a group of feral Alexandrine Parakeets in Stanmore, NW London. Superficially similar to the related Ring-necked Parakeets which have also colonised NW London and overlap in the same area, the Alexandrines are larger, noisier, have the pink patch on their shoulders, no pink eye ring, and an all-red beak (top and lower) visibly larger than that of the Ring-necks.
What looks like a yellow eye-ring is a yellow-white iris with grey eye-ring. Some of the feral group may be Ringnecks.