Hummingbird Day Event Postponed 

Out of an abundance of caution and due to the strict guidelines concerning COVID-19 coming from both the state and federal governments, we have made the decision to close the Arboretum to the public until further notice. We feel this is the most socially responsible action as we must all do our part to mitigate the impact of COVID-19. A small number of staff will be onsite to care for plants in our nursery and maintain our grounds. As always, we are grateful for our garden community and your continued support.
Regardless of what humanity is currently wrestling with, the hummingbirds are very active in the gardens and will be here when we reopen. We look forward to welcoming our community back to the Arboretum in the future. In the meantime, we can all take time outdoors in open spaces and our own gardens to reconnect with nature.

The Arboretum is home to many lovely plants that attract one of the Garden's most celebrated birds - the Hummingbird! (Plant List PDF).

This time of year the Arboretum hosts both Anna’s and Allen’s hummingbirds, the two most common species in Northern California“The density of hummingbirds — the number per area in the Arboretum — is ridiculously high,” says Bruce Lyon, professor of Ecology and Evolutionary Biology at UCSC“You can watch them feeding on flowers, you can watch their courtship, you can watch them chasing different species — it’s a great opportunity to see some pretty amazing hummingbird biology.

Additional Hummingbird Facts

Garden Tips for Hummingbirds


                               Anna’s Hummingbird (Brad Lewis)


 Anna’s hummingbird was named for Princess Anna de Belle Massena, a 19th Century Italian Duchess. Though John James Audubon was allegedly smitten with her, it was naturalist René Primevère Lesson who christened the bird in her honor. While the females are mostly green, the males have an iridescent magenta crown and gorget. The Anna's has a single J shaped dive. The Anna’s hummingbird was recently declared the fastest animal on the planet, relative to its size. They can reach speeds of 50mph, or nearly 385 body lengths per second, a Eurofighter's top speed of 1,320mph jet manages to cover just 39 body lengths per second.


Allen's Hummingbird (Ferd Bergholz)

                               Allen's Hummingbird (Ferd Bergholz)


Allen’s hummingbird (pictured at right) was named for the American collector and taxidermist Charles Andrew Allen (1841-1930). The male has a green back and forehead, rust-colored body and tail, and an iridescent orange-red throat. While the mostly green females have whitish throats with dark speckles and their tail has white tips. The males offer Arboretum visitors a spectacular sight: as part of the mating ritual, they fly in a frantic up and down U-shape that culminates with a high-speed dive.



Behavior of a bird is another “tell”: Allen's and Anna's have overlapping territories - Allen's tend to dominate territories when seasonally migrating. The year-round Anna's fly in low to feed and try to go unnoticed, during this time of territorial overlap.


As you meander through the gardens, it’s helpful to know the “parts” of a hummingbird. A bright-colored area on the throat and chin is called a “gorget” (not seen on females), and a bright-colored area on the forehead and crown is called the “helmet.” The tail offers a clue if it has white or rufous (orange-colored) spots and, if so, their size and location. The bill can identify the species if unusually long, relatively short, or colored red.