First up the Parakeets. Until I lived in the London suburbs I'd always assumed that the parakeets were an urban legend, or at least strongly exaggerated. Turns out not to be the case. There are anywhere between three and seven of them knocking around in our corner of South East London. They are social, noisy, argumentative and (quite honestly) usually referred to me as the Green Feather Hooligans.
They do behave delightfully like the parrots and tropical birds you see in aviaries. Shown here with one hanging upside down to attack the coconut fat ball and the other waiting his turn patiently (ish).
You can see three of them here sitting in a tree in our garden. Three seems to be about the most that will share a tree at once. The preferred roosting patterns involve sitting in trees that are several gardens removed, two or three in a tree, and squawking loudly and enthusiastically. Then all the squawking fails they take to the wing and chase each other around the trees. So sort of game of tag on the wing (!)