I understand there are several colonies of escaped parrots--some large enough to be a nuisances to farmers.
http://news.nationalgeographic.com/news/2003/04/0407_030407_parakeets.html
Bittner lives in Telegraph Hill, close to downtown San Francisco. And so does a colony of cherry-headed conures Aratinga erythrogenys, also known as red-masked parakeets.
The birds first turned up in the early 1990s. They were wild-caught birds from Ecuador and Peru which either were released or escaped after being imported as pets. Bigger than the average parakeet, with plumage that flashes bright green and red, they soon caught Bittner's eye. He's been captivated by them ever since.
Biographies of those intrepid urban settlers appear on Bittner's Web site, The Wild Parrots of Telegraph Hill. The stories document the trials and tribulations of an intriguing range of characters, just like a television soap drama.
There's poor old Scrapper, for instance, henpecked for years by an abusive mate that plucked out all his breast feathers. In the end he split with the old bird and set up home with a younger, nicer female. He still bears the scars of his former pairing.
Then there's Patrick, who shies away from long-term commitment. Bittner's biography of him adds: "He's had a few tentative short-termers that lasted a few months, but never a relationship that lasted years. That's extremely unusual within the flock. He seems a reasonably contented parrot."
One of Bittner's favorite birds is Fanny who comes to sit on his shoulder and take seeds from his mouth. It shows the closeness of Bittner's relationship with these wild birds, which are naturally wary of humans.
Noisy and Funny
"Generally the birds are pretty popular," Bittner said. "They are colorful, noisy and funny. They do a lot of acrobatics, things you don't usually think of a bird as doing. They hang upside down from the power lines. They chase each other and fight. Yet they also make devoted pairs. You often see them preening each other and being, well, 'lovey dovey'. People enjoy seeing all of that."
Urban folks also enjoy the performance of a parakeet flock in full display mode. Bittner recalls a day when the birds were gathered in a park and "screaming like lunatics" until they reached fever pitch. Suddenly they lifted as one from the trees and spiraled into the sky. Everybody nearby broke into spontaneous applause.
As San Francisco's cherry-headed conure population grows, Bittner will find it harder to keep tabs on individuals. The flock now has 85 birds, and is increasing each year. It is even listed as an attraction in some city tour guides.
Bakersfield's Rose-ringed Parakeets
In other cities parakeet colonies can be much bigger. In Bakersfield, California, there are over 1,000 rose-ringed Psittacula krameri, or ring-necked, parakeets. Native to the Indian subcontinent and sub-Saharan Africa, the species probably first gained a foothold in Bakersfield after a hurricane-force storm destroyed an aviary in 1977. Alison Sheehey, from California State University Bakersfield, has studied the birds since 1998. She believes their success is due largely to the manmade nature of their surroundings.
"Many urban plants are from tropical to subtropical climates. This established a habitat for the birds long before they took up residence. There are also plenty of backyard fruit and nut trees that keep them well fed," she said.
The popularity of garden bird-feeders is another important factor, and Sheehey says this "smorgasbord of parakeet delights" means the birds are unlikely to leave the city.
Sheehey says it's difficult to gauge the impact of parakeets on native fauna. Nevertheless, she has witnessed altercations with other birds.
"I have seen them battling with European starlings Sturnus vulgaris and acorn woodpeckers Melanerpes formicivorus over nest cavities," she said. "The parakeets won every time."
Promiscuous Parakeets
Sheehey has also encountered fickle behavior among these supposedly monogamous birds.
"One day while watching a nesting flock I observed a male tell his spouse he was going out. He looked back, and seeing she was gone, made a wide circle and came back to a neighboring tree. The good-looking little hen next-door came out, they flirted and, well, you know what happened next."
In London, England, rose-ringed parakeets have been present for some 30 years. Until recently the population expanded slowly reaching 1,500 birds in 1996. But by 2002 the number had soared to 7,000.
Some scientists believe this is an example of the Allee effect, where an introduced species keeps a low profile for a long period before suddenly exploding in numbers. This happens when enough potential mates are around for them to find each other.
But whatever the reason for the increase, it's possible the birds could lose their popular appeal if they stray beyond city limits.
In the fall of 2002, a rose-ringed parakeet flock stripped a vineyard of its crop at Painshill Park in Cobham, near the outskirts of London.
"It would have been a really fantastic year," said Teige O'Brien, Painshill Park's development manager. "But we ended up with just 500 bottles of red wine. The parakeets seem to be immune to scarecrows, things that go bang and all the other bird-scaring devices. I suspect this is going to be an annual problem."
The Royal Society for the Protection of Birds, Europe's largest wildlife conservation charity, is aware of such fears.
However, spokesman Andre Farrar added: "Any introduced species could cause a problem many years down the line. But the parakeets will carry on enchanting London's bird-loving gardeners."
They taught each other by copying behavior and were well-rewarded. They loved hot dogs!
