The flash of vibrant green and crimson against the San Francisco skyline reveals the city’s celebrated wild parrots. Their presence sparks curiosity about how they arrived and how many live there. Understanding the size of this unique population requires identifying the specific species and recognizing the challenges of counting highly mobile animals.
Identifying the San Francisco Flock
The majority of the city’s famous avian residents are Cherry-headed Conures, scientifically classified as Psittacara erythrogenys. This mid-sized parrot species is easily recognized by its brilliant green plumage and the vivid, deep red feathers covering the face and crown, resembling a distinctive helmet.
The conures are highly social and vocal, known for their loud, raucous calls that carry across the city’s neighborhoods. While these vocalizations make the flock easy to locate, their ability to travel rapidly and roost in high, dense foliage complicates precise counting. The flock also contains a small number of hybrid birds, resulting from interbreeding with a Mitred Conure that joined the group.
Estimating the Current Population
Pinpointing an exact, stable number for the San Francisco parrot population is complicated by their mobility. Reliable estimates place the total population in a consistent range, generally fluctuating between 200 and 300 individual birds. Recent observations suggest an approximate population of around 220 birds.
The primary method for estimating population size involves roost counts. Observers wait near known communal roosting sites, often in tall Canary Island date palms, and count the birds as they arrive at dusk. This technique minimizes the chance of double-counting by accounting for the entire flock gathered in one place.
The count is inherently variable due to multiple factors. Comprehensive daytime counts are nearly impossible because the birds split into smaller foraging groups. Furthermore, the count is a snapshot rather than a fixed total, influenced by natural changes like breeding success and mortality. The population is also sporadically increased by new escapees from the pet trade joining the established wild group.
The Exotic Origins and Local Range
The Cherry-headed Conure is native to Ecuador and Peru. The San Francisco flock originated from the international exotic pet trade, successfully naturalizing in the urban environment. Most founding birds were either intentionally released by overwhelmed owners or were accidental escapees from private homes or dealers.
The conures first gained attention in the 1980s and 1990s, establishing themselves around Telegraph Hill and the Embarcadero. As the population grew, their range expanded significantly. They now regularly fly across large swaths of the city, utilizing parks and neighborhoods far from their original base.
Their territory encompasses areas like the Presidio, Golden Gate Park, and Russian Hill, where they find suitable food and roosting sites. Sightings also extend beyond the city limits, reaching south into the Bay Area peninsula in communities such as Brisbane and Sunnyvale.
Monitoring and Ecological Status
Local agencies view the Cherry-headed Conures as a naturalized population, not invasive. They are not considered a major threat that displaces native bird species because their flexible diet utilizes resources local birds often ignore. The parrots feed on fruits, seeds, and blossoms from non-native, ornamental trees widely planted throughout the city, such as loquats and certain palms.
Monitoring efforts focus on the overall health and stability of the flock within the urban ecosystem. A long lifespan, sometimes exceeding 50 years, contributes to the flock’s stability. A specific concern for their well-being is the risk of accidental poisoning from rodenticides used in city pest control.
Non-profit organizations occasionally intervene to rescue and rehabilitate birds that have fallen ill, often from ingesting poisoned prey. Despite being non-native, the flock is seen as a charismatic and stable part of the urban wildlife community.