A hawk sweeps overhead, hits a scrubby hillside, and bounces back into the air, a small clutch of gopher fur and feet swinging from its talons. Other hawks, and owls, hunt gophers in San Francisco’s Presidio. So do herons.
These are just a few of the scores of bird species that live for at least part of the year in this large urban park, part of the Golden Gate National Recreation Area. During a December bird count, volunteers with binoculars and notepads observed 175 species in San Francisco, with 110 tallied in the forests and scrub of the Presidio. The volunteers saw Pacific wren, western bluebird, several woodpecker species and chestnut-backed chickadee. They saw nonnative species, too, like the European starling, house sparrow, rock pigeon and Eurasian collared dove.
They also saw parrots, though these birds were not exactly a surprise to anyone. These beautiful natives of the tropical Andes first appeared in San Francisco in the 1980s as a group of several individuals that probably escaped from a pet importer. They established themselves on and around San Francisco’s Telegraph Hill and, as they bred and increased in number, attained a degree of local stardom.
That stardom, again, was hardly a surprise. The charismatic birds are brilliantly colored and have a penchant for garrulous squawking and dangling upside from branches and balconies. Today, the parrots — actually representing two species of parakeet, or conure — are objects of pride and fascination for many San Francisco residents. Easily seen in many parts of the city, they have been celebrated in newspapers, YouTube videos, a book and a film, and online tourist guides.
But not everyone is thrilled with the parrots’ presence.
“We know enough now about invasive species not to let them establish themselves,” says Josiah Clark, a San Francisco-based consulting ecologist who helps coordinate the annual Presidio bird survey. “It’s kind of like, how long does a doctor wait to do something about an infection? When do you stop it?”
In the year 2000, there were probably about 50 conures in San Francisco. There are now probably between 200 and 300, and it seems probable to some ecologists that they are competing with native songbirds, and possibly even raptors, for nesting cavities and for food.
The parrots gained fame in 2004 with the publication of The Wild Parrots of Telegraph Hill, by Mark Bittner. A film by the same title was released the following year.
Bittner was among the very first San Franciscans to observe the parrots. He first took notice of a group of four in 1990 outside his home by Telegraph Hill, on which the landmark Coit Tower stands. At the time, the birds ranged as far away as Fisherman’s Wharf and Dolores Park, but they began gathering daily at Bittner’s fire escape, where he fed them seeds and got to know them as individuals. He gave them names, watched as pairs turned into families, and over time became a friend of the flock.
About a decade ago he stopped feeding the birds and reverted to being more of an observer of the birds than a steward. Bittner even pushed for a city ordinance that today prohibits people from feeding the birds in public spaces, though it’s probable that many residents still provide nuts and seeds for the birds.
Though there are many more conures now than there were in the 1990s, the birds’ numbers don’t seem to be growing rapidly. Davis-based scientist Jamie Gilardi, executive director of the World Parrot Trust, doesn’t believe the San Francisco conures pose a threat to native wildlife.
“There are just too few of them,” he says. Invasive monk parakeets in Florida number in the hundreds of thousands, Gilardi points out, and still the impacts on wildlife seem to be fairly limited because the birds, introduced from South America, are confined mostly to cities.
Gilardi thinks ecologists jump to conclusions too quickly when it comes to nonnative species.
“There is a kneejerk reaction that any nonnative species must be having impacts on native species, even if they really aren’t,” he says.
The conures of San Francisco tend to use environmental niches with which few native birds interact.
“They’re eating out of artificial food sources and nesting in nonnative tree species,” says Bittner, citing the tops of Canary Island date palms, widely planted in San Francisco, as favored nesting places for the birds.
But Clark says he has twice seen parrots nesting in tree cavities — once in a pine, once in a palm — that he had previously seen occupied by pygmy nuthatches, tiny songbirds that excavate their own nesting holes and use them as communal shelters, often for successive generations.
Another local naturalist, Dominik Mosur, thinks the conures could be at least partly responsible for the disappearance of American kestrels from San Francisco. These small falcons, he says, have vanished from urban bird surveys in the same time span in which the conure numbers have exploded.
Since falcons are cavity nesters, like the parrots, it is plausible, Mosur says, to suspect the growing parrot population has displaced the small raptors. Mosur says he has not seen this happen but doesn’t rule it out as a possibility.
“Based on the size and nest site preference, these two are potential competitors,” Mosur says.
Tropical birds living in temperate cites is not a phenomenon unique to San Francisco. The same conures that have colonized the San Francisco peninsula, in fact, are relatively common in the Los Angeles area, as are almost 30 other introduced bird species, according to Kimball Garrett, the ornithology collections manager of the Natural History Museum of Los Angeles County. He says the urban area from Los Angeles to Tijuana, Mexico is a haven for these introduced species, most of which can be found in other cities around the state.
In nearly every case, the birds have been introduced by people and have thrived in highly altered urban environments, where the presence of subtropical flowering and fruiting plant species provides a year-round food supply that does not exist outside of most city limits, at least in temperate climate zones.
“This appearance of exotic birds is symptomatic of large-scale habitat change through urbanization,” Garrett says. “Most of these species are essentially restricted to cities.”
This, he says, means most of these introduced birds are not interfering with native wild birds.
However, there are a few nonnative birds that Garrett says could become problematic, as they have shown potential adaptability to California’s native habitat. The Nanday parakeet, for one, is now living in native woodlands near Santa Monica. The birds, native to South America, are cavity nesters and could displace other native species, like kestrels, screech owls and woodpeckers, which also rely on cavities to place their nests and rear young, Garrett says.
In Bakersfield, the rose-ringed parakeet now lives in screeching flocks of thousands. Garrett says it’s likely just a matter of time before the birds learn to take advantage of the rural landscape surrounding the city.
“If I was a farmer I’d be worried about those birds,” he says.
Some nonnative birds have moved into California by their own power. The great-tailed grackle, common today in much of the state, first appeared north of Mexico in the 1960s, Garrett says, and were evidently attracted by agricultural development in southern and central California.
The monk parakeet seems poised to do the same. Originally from temperate Argentina, the bird was introduced to parts of the United States via the pet trade. It is now expanding its range. It has caused problems in Florida, where the birds’ habit of building giant communal nests atop electrical towers and telephone poles has damaged the region’s power infrastructure. Monk parakeets are common in some Mexican cities, Garrett says.
“They aren’t in California yet but I think they’ll get here soon enough, since they’re just south of the border now,” Garrett says. “I don’t think even Trump can build a wall that can keep those birds out.”
The spread of at least some nonnative birds has been blamed, mostly in jest, on Shakespeare. A 19th century literary buff named Eugene Schieffelin had the bright idea to introduce to the United States the birds mentioned in the works of Shakespeare. He made failed attempts at introducing at least two European bird species. His efforts succeeded, though, with the European starling. Schieffelin released several dozen. Today, some 200 million of the birds occupy North America and cause almost a billion dollars each year in crop damage. These starlings also pose a very real threat to native birds by competing for tree and cliff-face nesting cavities.
In San Francisco, it may be too early to decide whether or not Andean conures — which have been spotted on the north side of the Golden Gate Bridge in Sausalito and more than 10 miles south of Telegraph Hill in the city of Brisbane — are upending the ecology of San Francisco.
Bittner, who says he took an interest in birds in general precisely because of his initial relations with the parrots, says he thinks the conures, as educational ambassadors for all birdlife, may actually be providing an indirect but net benefit to the ecology of the San Francisco Bay Area.
Clark worries that the opposite is happening — that the natural charisma and color of the conures has distracted the general public from the region’s native biodiversity.
“Why is it that we can so easily celebrate parrots imported from Ecuador but that nobody knows what a bushtit is?” Clark says. “Why do we have a movie about the parrots of Telegraph Hill but not a movie about the brown creepers of Golden Gate Park or the snowy plovers of Ocean Beach? I’ll tell you — it’s because the parrots are like the only species people know of the 175 that live in San Francisco.”
The conures at least deserve to be studied, Mosur argues. Their presence in San Francisco offers a rare learning opportunity, he says.
“Even though they’re out of place here, being able to study their social structures could be worthwhile,” Mosur says. “It’s a unique opportunity to observe a population of animals out of their native habitat.”
Banner: Cherry-headed conures feast on a discarded apple core in San Francisco. Photo: Ingrid Taylar, some rights reserved