The Parrots of San Francisco

[Catherine]

Quote:I am only guessing here, but Parrots have quite long life spans don't they? If someone had released one or two -(or those had escaped) -then if something similar happened say five or ten years later, they could have bred.

There might have been a time when having Parrots as pets was particularly "fashionable"....but some escaped into the wild and obviously created more and more...

That is what they think really happened. No one really believes the story about the pet store letting them go. They were popular and many were imported. If even one every year or so was lost they live long enough to meet up and pair off and lay eggs.
It would take a few years before there were enough to be noticeable. Once it was known that there was a flock of parrots people who were tired of their bird would turn it loose near them. There was even a different similar species released that crossed with them.

A parrot is a big commitment and people who get them don't always look at what that commitment involves. 
It was just fortunate that the birds could survive. I think there are bird flocks in other cities, but this is the most famous.

There are flocks elsewhere, even in Europe.

https://en.wikipedia.org/wiki/Feral_parrot

Nature is very adaptable and parrots are especially clever. They know enough to find humans to feed them and they stay in the cities so they must be using the city habitats to survive. Parrots are survivors.