
By Andrew LaBar
Editor’s note: This article was originally published in October 2009, it has been updated and revised September of 2023. This year we are spotlighting articles featuring animals and plants from our North Richmond Urban Nature Loop. Click here to read more about all the animals featured in the stickers.
Summer is ending and Fall is soon to begin. Along with the many changes autumn brings, like pumpkin spice, spooky season, and crunchy leaves, Fall is an exciting time to gaze out your window. The sun is shining brightly and with it comes some of the Bay Area’s best weather. If you’re lucky, the beautiful Anna’s hummingbird could be putting on a lively show right in front of your eyes.
Physical Appearance
Anna’s hummingbird is the largest hummingbird on the west coast. At maturity, it reaches nine or ten centimeters in length. Anna’s body showcases marvelous bronze and green feathers, making these creatures shimmer in the sunlight. They have gray bellies and small white spots behind their eyes. Most distinctively, mature males sport a brilliant rose-red crown and throat, making them easy to distinguish from other native hummers. The females of this species are less showy than the males with plumage that display flashy bronze/green coloring and grays and browns on their wings, crown, and throat.

Credit: Doug Greenberg, “Anna’s Hummingbird ”
Range and Habitat
Humans have redefined this hummingbird’s habitat. While their original range was limited to the coasts and inland mountains of Southern and Baja California, Anna’s Hummingbird is now widespread across much of the western United States. Since the 1930’s this small bird can now be commonly seen as far north as British Colombia and as far east as Arizona and Texas. This rapid expansion in their range is attributed mainly to humans and how we have interacted with our environment. Due to the widespread suburbanization of the western US and the accompanying introduction and planting of non-native ornamental nectar-filled plants, and the popularity of urban hummingbird feeders, Anna’s hummingbird now thrives in urban and suburban yards, gardens, and parks.
Diet
Anna’s hummingbird is famous for having quite the sugar tooth. They use their slender beak to feed on the nectar found in sugary plants like red-flowering currant, hummingbird sage, California fuschia, and much more! Despite this famed love of sweet nectar, hummingbirds are also voracious predators. In fact, Anna’s hummingbirds typically eat more insects than most other hummingbird species. When they are young, baby hummingbirds cannot feed themselves, and with their high metabolism, additional sources of nutrition are required. Protein and carb-loaded caterpillars are their favorite treat as they are soft and easy to digest. But they are not picky and will eat any number of small insects or spiders that they can scoop up on the wing and pluck off branches and leaves.
Mating and Life Span
The mating season for Anna’s hummingbirds fall during the rainy season, between November and April. During this time, the female bird is busy building her soft nest, composed primarily of spider webs, plants, feathers, and hair on the inside, and bark and other hard, camouflaging bits on the outside.

Credit: Anna’s Hummingbird feeding young | Alexandra MacKenzie | Flickr
Once her nest is suitable, the female bird lures an interested male towards her nest and perches on the side. In an effort to impress her, the male orchestrates a series of dive bombs around the female, showing off his skill and fiery red feathers. After mating, the male bird leaves and does not help raise the young brood. Females can have two broods per mating season, incubating the eggs and nesting their offspring for about two months before they achieve independence. The average lifespan of Anna’s hummingbirds is eight and a half years.
Flighty Behavior
Anna’s hummingbirds are very territorial. Grouchy males will dive at creatures entering their territory, regardless of size. The bird may fly as high as forty meters into the air before diving at the individual is an impressive show of brilliant color. The bird also has a distinctive bird call, heard while eating, and before mating.
Look out for these colorful flighty birds in your garden this fall!
Sources:
https://www.audubon.org/news/annas-hummingbirds-are-expanding-their-range-human-help
https://www.thespruce.com/feeding-hummingbird-insects-385954