What's Up With The Birds On Telegraph Hill?

Did some googling and I found that Mark Bittner wrote a book and devoted a website to this. All info came straight from the site

What kind of parrots are they?

Most of the birds in the flock are of a species known variously as the cherry-headed conure, red-masked conure, and red-headed conure - all pet trade names. Ornithologists call them red-masked parakeets, and the scientific name is Aratinga erythrogenys. In the summer of 1995, a female mitred conure (or mitred parakeet, Aratinga mitrata) showed up. She began to breed with the cherry heads, and continued to do so until at least 2006. I don't know whether she's still alive. The hybrid offspring are fertile, so there are quite a few double hybrids in the flock now as well. In the past there have been two blue-crowned conures (blue-crowned parakeet, or Aratinga acuticaudata).

Where do they come from?

The cherry-headed conure is from a small territory on the west side of the Andes in southern Ecuador and the extreme north of Peru. The mitred conure ranges from southern Peru through central Bolivia, on down to northwestern Argentina.

How did they get here?

While I don't know specific events, I do know that the flock was started by wild-caught, imported parrots from South America. (The founders wore quarantine bands particular to imported birds.) Before the practice was restricted in 1993, it was legal to import wild-caught parrots into the United States, and they were brought in by the millions. The cherry heads were inexpensive - often less than $100 per bird - and the people who bought them found that the wild birds despised captivity. They were noisy and they bit. In some cases, birds escaped; in other cases, I'm sure that they were deliberately released by frustrated owners.

Where can I see them?

They follow the fruiting of the trees. There are so many of them now that if you are in the north waterfront area, you're bound to encounter them at some point. Except for up the area near Coit Tower, Telegraph Hill is not actually a very good place to look for them. They are usually in yards, where it's impossible to get a good view. A better bet is Upper Fort Mason, near the Golden Gate National Recreation Area headquarters.

What is their territory?

Over the years, the flock's territory has grown considerably. It seems to grow a little more each summer. You can see the parrots year-round along the north waterfront area - from the the Ferry Building area clear around to the east side of the Presidio. In the summer, they extend their territory down through the center of the city and on down to Brisbane. They were never really the Wild Parrots of Telegraph Hill. That's what people called them when I first started seeing them. But nobody knew much about them then. Telegraph Hill is just one of many areas they forage in. You will see them here, but when and on what part of the hill is unpredictable.

Do they migrate?

No. Parrots stay in one territory all their lives.