How San Francisco's Trees Provide Wildlife Habitat

Red-masked parakeet, hooded oriole, and coast live oak acorn photos via Wikimedia Commons.

San Francisco's street trees provide shade, clean air, and capture stormwater. They also create a network of habitats for birds, butterflies, and other wildlife that call our city home. Below are some unique examples of how the trees we plant support wildlife in our city.

The Parrots of Telegraph Hill have a home in our trees. San Francisco's official city animal, the red-masked parakeets, have made themselves at home in the city since the late 1980s. Descended from escaped or released pet birds, the population has grown to more than 200. These colorful birds rely on the city's Canary Island date palms and other fan palms for nesting sites.

Market Street is a butterfly thoroughfare. It might not be the first place you think of to spot butterflies, but San Francisco's downtown streets provide a habitat for the western tiger swallowtail. Naturalists studying butterflies along Market Street discovered that these yellow and black butterflies are attracted to the corridor of London plane trees. The tree-lined street creates a landscape that resembles the waterways and wooded corridors where these butterflies naturally travel.

Canary Island palms welcome hooded orioles. San Francisco's Canary Island date palms shade the Embarcadero, Market Street, and Dolores Street. They have also helped hooded orioles expand their range northward into the city. These bright yellow birds find food and shelter among the palms, demonstrating how even trees originating far from California can contribute to urban biodiversity.

Native oaks are miniature ecosystems. Coast live oaks, one of San Francisco's most important native tree species, support an extraordinary range of wildlife. Their acorns feed California scrub-jays and gray squirrels, while their branches and leaves provide habitats for insects and other birds. In fact, coast live oaks support more species of small moths on the San Francisco Peninsula than any other plant species.

We believe a healthy urban forest should benefit everyone, including our many wild neighbors. By planting and caring for trees throughout San Francisco, we're creating a greener, more vibrant city where people and wildlife can flourish together.