What trees do Anna’s hummingbirds nest in?

Anna’s hummingbirds (Calypte anna) are small, colorful birds found along the west coast of North America. They get their name from Anna Massena, Duchess of Rivoli, who was a patroness of naturalists in the early 19th century. These tiny birds have metallic green backs and rose-pink throats, making them easy to identify. Anna’s hummingbirds are highly territorial and males perform elaborate courtship displays to attract females. An important factor in their breeding success is finding appropriate places to build their tiny nests. This article will explore what types of trees and shrubs Anna’s hummingbirds use for nesting.

Anna’s Hummingbird Nesting Requirements

Anna’s hummingbirds have some specific requirements when it comes to selecting nesting sites:

• They prefer trees and shrubs that have small branches and twigs that can support their tiny nests.
• The nest is typically placed on a downward sloping branch which provides some shelter from rain.
• Trees and shrubs that have dense foliage are favored as this helps conceal the nest from predators.
• Anna’s hummingbirds often reuse and repair old nests from previous years, so established nesting trees are prime real estate.
• Proximity to nectar-rich flowers is also a factor, as the parents need to frequently feed their chicks.

With these requirements in mind, let’s look at some of the most common trees and shrubs that Anna’s hummingbirds choose for nesting.

Eucalyptus Trees

Eucalyptus trees are a favorite nesting spot, especially the blue gum eucalyptus (Eucalyptus globulus). Here are some reasons why:

• The long, thin leaves provide excellent coverage for nests tucked into branches.
• Clusters of small shoots and twigs growing off larger branches make ideal nest anchors.
• Their height makes nests less vulnerable to many ground predators.
• In urban areas where native plants are scarce, eucalyptus groves can provide vital habitat.

In a study conducted in Santa Monica, California, researchers found that Anna’s hummingbirds preferentially nested in blue gum eucalyptus trees over all other tree species. Of the 43 hummingbird nests observed, almost half were built in eucalyptus trees.

Oaks

Several species of oak trees are also favorite nesting spots. This includes coastal live oak (Quercus agrifolia), canyon live oak (Quercus chrysolepis), and huckleberry oak (Quercus vacciniifolia). Here are some of the features that make oaks attractive:

• Their branching structure and clustered leaves provide cover and support for nests.
• Many oak species are very long-lived trees, allowing reuse of nest sites over many years.
• Acorns from oak trees attract insects that adult hummingbirds eat.
• Oaks have a widespread range that overlaps with Anna’s hummingbird habitat.

In some oak woodlands of California, such as Santa Barbara County, over 25% of Anna’s hummingbird nests can be found in oak trees.

Cypress

Cypress trees, particularly Monterey cypress (Cupressus macrocarpa) and Arizona cypress (Cupressus arizonica), provide good nesting opportunities. Reasons include:

• Their dense, evergreen foliage conceals hummingbird nests from predators and buffers from severe weather.
• Long lifespan means nest sites remain usable for many years.
• They are often found near suburban or coastal areas that hummingbirds frequent.
• Monterey cypress is native habitat for Anna’s hummingbirds along California’s central coast.

Cypress trees can comprise over 15% of nest trees used in some Anna’s hummingbird populations along the coast.

Willows

Weeping willows (Salix species) are a less common but sometimes preferred nest tree. Benefits include:

• Their drooping branches and shoots create protected nest sites underneath the canopy.
• The presence of willows indicates a nearby water source which hummingbirds need access to.
• Insect life attracted to willow trees provides food for the hummingbirds.
• Soft leaves and branches make it easy for hummingbirds to excavate nests.

One study in Arizona found that while only 6% of trees surveyed were willows, they contained 17% of Anna’s hummingbird nests.

Other Trees and Shrubs

In addition to the most common trees described above, Anna’s hummingbirds will nest in a wide variety of other species including:

• Maples
• Alders
• Birches
• Cedars
• Firs
• Hawthorns
• Cottonwoods
• Sycamores
• Mulberries
• Cherries
• Apples
• Lilacs
• Viburnums
• Toyon

Basically any tree or shrub that meets their requirements for small branches and dense foliage may potentially be used. Expanding the diversity of vegetation in yards and parks can help provide more nesting options for Anna’s hummingbirds.

Best Trees Overall for Nesting

While Anna’s hummingbirds are flexible in their nest site selections, some clear patterns emerge from research:

This table summarizes results from a nesting study in California and shows eucalyptus trees hosted nearly half of all Anna’s hummingbird nests. Oaks and conifers like cypress were also very popular. While willows were less common, they were used at rates higher than their availability.

Ideal Nesting Trees for Yards

For homeowners who want to encourage nesting in their yards, the following trees are recommended:

• Blue gum eucalyptus – Provides ideal cover and nest sites.
• Oak species – Coast live oak and huckleberry oak are native choices.
• Monterey cypress – A natural choice for coastal areas.
• Weeping willow – Just be sure site stays moist.
• Fruit trees – Cherries, apples, mulberries provide food sources.

Focus on planting native trees when possible. Also have nectar-producing flowers and a trickling water source nearby. Keep cats indoors so they do not disturb nests.

Threats to Nesting Trees

Anna’s hummingbirds face habitat loss from human development and climate change:

• Urbanization removes native vegetation that hummingbirds rely on.
• Non-native invasive plants crowd out nest trees in wild areas.
• Flowering plants blooming earlier due to climate change may mismatch chick rearing seasons.
• Drought stresses and kills nesting trees like oaks and eucalyptus.
• Increasing wildfires incinerate forests and nesting habitat.

To help counteract these impacts, preserving native habitat, reducing emissions, and expanding urban green spaces are all important. Providing backyard nesting trees, limiting pesticide usage, and planting climate resilient vegetation are all actions individuals can take.

Conclusion

Anna’s hummingbirds are specialized in their nest site requirements, favoring trees and shrubs that offer small branches for support along with dense foliage for concealment. Eucalyptus, oaks, cypress and willows comprise prime nesting habitat along the California coast where these hummingbirds are common. Yard trees like eucalyptus, oaks, and fruit trees can be planted to attract nesting hummingbirds. As habitat loss and climate change threaten populations, preserving native vegetation and reducing ecological impacts are needed measures. With care and stewardship, the sights and sounds of these remarkable pollinators can continue to brighten our neighborhoods.