Anna’s hummingbirds (Calypte anna) are small, colorful birds found along the west coast of North America. They are known for their iridescent green and pink feathers and their incredibly fast wingbeats. Anna’s hummingbirds build small, compact nests in which they lay their eggs and raise their young. But what types of trees do these tiny birds prefer to build their nests in? Keep reading to find out more about Anna’s hummingbird nesting habits and their preferred nesting trees.
Overview of Anna’s Hummingbirds
Here are some quick facts about Anna’s hummingbirds:
– Scientific name: Calypte anna
– Average size: 3-5 inches long with a wingspan of 4 inches
– Identifying features: Green head and back, gray underparts, rosy pink throat and crown
– Diet: Nectar, small insects
– Habitat: Open woodlands, chaparral, gardens, parks from sea level to elevations over 9,000 feet
– Range: Year-round along the Pacific Coast from British Columbia to Baja; some inland movement in winter
Anna’s hummingbirds are the most common and widespread hummingbird found along the Pacific Coast. They are scrappy, territorial birds that will aggressively defend feeding areas from intruders. Their wings can beat up to 70 times per second, allowing them to hover in place while feeding on flower nectar.
Anna’s Hummingbird Nesting
Anna’s hummingbirds build small, compact nests made of plant down, spider webs, and lichens bound together with spider silk. The external diameter of the nest is typically 3-4 inches wide and 2-3 inches tall. The inner diameter of the nest cup is about 1.5-2 inches across and 0.5-1 inch deep, just large enough to accommodate the female hummingbird and her tiny eggs.
Nest building is done primarily by the female over a period of 5-10 days. She uses her body as a mold to shape the interior, pressing her body into the nest materials to create the cup shape. The nest is well-camouflaged on the outside with lichens and bound plant fibers. On the inside, the female lines the nest with soft plant down for insulation.
Anna’s hummingbird nests are engineered to stretch and expand as the chicks grow. The female also continues to add nest material during incubation and the nestling period. The tightly woven spider silk helps bind everything together while allowing the structure to expand without falling apart.
Preferred Nesting Trees
When it comes to selecting a nest site, Anna’s hummingbirds prefer trees that provide good coverage for the nest and easy access to flowering plants. Here are some of their top choices:
1. Eucalyptus
Eucalyptus trees, especially the blue gum eucalyptus (Eucalyptus globulus), are a favorite nesting site. They offer the hummingbirds dense cover and an abundance of small branches and twigs for anchoring the nest. Eucalyptus trees also have stringy bark that the birds use in nest construction. These trees bloom in winter, providing nectar when other flowers are scarce.
2. Sycamores
Sycamores (Platanus sp.) are massive shade trees that provide dense foliage for nest concealment. Their branching structure gives hummingbirds many options for nest placement. Sycamores also produce lots of cottony seeds that hummingbirds incorporate into their nests.
3. Oaks
Oaks like coast live oak (Quercus agrifolia) furnish sturdy horizontal branches as well as lichens and plant fibers for nest materials. Their spring blossoms provide an early nectar source.
4. Fruit Trees
Orchards and gardens filled with blooming fruit trees draw nesting Anna’s hummingbirds. Citrus trees, apple trees, cherry trees, and others produce flowers with abundant nectar. They provide cover and nesting materials too.
5. Cypress
Cypress trees like Monterey cypress (Cupressus macrocarpa) offer dense foliage for nest concealment. Their small cones and twigs also get woven into Anna’s hummingbird nests.
Other Common Nest Trees
In addition to their favorites, Anna’s hummingbirds will nest in a wide variety of other trees:
– Willows (Salix sp.)
– California bay laurel (Umbellularia californica)
– Bigleaf maple (Acer macrophyllum)
– Dougals fir (Pseudotsuga menziesii)
– Coast redwood (Sequoia sempervirens)
– Pine (Pinus sp.)
– Olive (Olea europaea)
– Palms
The most important factor seems to be dense surrounding cover to hide the nest rather than the type of tree itself. Anna’s hummingbirds are resourceful in utilizing what’s available in their environment.
Ideal Nest Sites
Beyond tree type, what makes for a prime nesting location for Anna’s hummingbirds? Here are some features they look for:
Foliage Density
Thick, dense foliage is attractive for nest concealment from predators and shelter from wind, rain, and sun. Trees and shrubs with small, dense leaves and branches are best.
Proximity to Flowers
Abundant nectar sources nearby allow easy energy access for the nesting female. Gardens and parks with flowering plants are favored habitats.
Branch Configuration
Hummingbirds prefer horizontal branches 8-20 feet off the ground with smaller branches and twigs for anchoring nests. Having multiple options helps them fortify nests and adapt to changing conditions.
Lichen Availability
Lichens growing on branches or the tree trunk provide excellent camouflage material. Sycamores, eucalyptus, oaks, and conifers that harbor lichens are attractive.
Spider Webs
An abundance of spider webs in and around potential nest trees gives Anna’s hummingbirds spider silk to weave their nests together.
Prior Nest Sites
Hummingbirds often rebuild a nest from previous years or build a new one near an old site. Established territories offer proven safety.
Morning Sun Exposure
Early sun helps warm the nest and dry morning dew. East facing branches are ideal orientation.
Nesting Chronology
Anna’s hummingbird nesting follows a predictable pattern through the stages of nest building, egg laying, incubation, and fledging:
Nest Building
– Period: Late November to early June, with a peak from late December to mid April
– Activity: Female gathers nest materials and constructs nest over 5-10 days
Egg Laying
– Period: December to June, with a peak from mid January to early May
– Activity: Female lays 2 tiny white eggs every other day
Incipation
– Period: January to July
– Duration: 16-19 days
– Activity: Female incubates eggs, leaves nest briefly 2-3 times per hour to feed
Nestlings
– Period: February to August
– Duration: 18-26 days
– Activity: Female feeds nestlings with regurgitated nectar and insects
Fledging
– Period: March to August
– Activity: Chicks leave nest and learn to fly at 18-26 days old
This cycle continues through summer with 2-3 broods raised. The presence of active nests can be used to predict each stage.
Interesting Facts About Anna’s Hummingbird Nests
Anna’s hummingbird nest architecture and nesting behaviors reveal some fascinating facts:
– Nests expand to double in size from when first built to when nestlings fledge. The female adds material as needed.
– Wind and rainstorms can tear nests apart requiring extensive repairs. Females tenaciously rebuild.
– Spider silk makes up about 5% of a nest’s total weight but is crucial for structural integrity.
– Lichens, moss, and leaves are skillfully layered on the outside for camouflage to mimic surrounding branches.
– Females may decorate the nest exterior with flowers, pieces of bark, animal fur, or ferns.
– Dense foliage above the nest helps conceal it but openings on the side allow the female to approach and depart directly.
– The petite nest cup only has room for the female’s body and the eggs/chicks. Her tail sticks out over the edge.
– Abandoned nests get recycled. Bits of old nests get woven into new nests in the same or nearby trees.
– Males assist with gathering some nesting materials but offer no help with nest building or rearing young.
Threats and Predators
Despite their petite size, Anna’s hummingbird nests face threats from predators seeking eggs and chicks for an easy meal. Here are common nest predators they must contend with:
Jays
Scrub jays and Steller’s jays are agile climbers that raid nests. Their intelligence helps them watch activity patterns and identify nest sites.
Crows
The larger American crow can reach nests in all but the tallest trees. Crows sometimes work in pairs or groups to find nests.
Owls
Small owl species like northern pygmy owls hunt at dawn and dusk when hummingbirds are active near nests.
Hawks
Sharp-shinned hawks and Cooper’s hawks stealthily approach through dense cover and snatch adult hummingbirds off nests.
Squirrels
Tree squirrels like western gray squirrels climb very well and can access exposed nests.
Snakes
Gopher snakes are expert climbers that raid nests to eat eggs and nestlings.
Wind and Weather
Storms can blow nests apart. Branches carrying nests sometimes break. Exposure and cold rain can be deadly.
Despite these threats, female Anna’s hummingbirds demonstrate remarkable persistence. They may repair or rebuild a nest multiple times after it gets demolished by weather or predators. Their tenacity ensures the next generation.
Conservation Tips
Here are some tips for providing habitat and helping Anna’s hummingbirds successfully nest in your yard:
– Plant a variety of nectar flowers that bloom in succession through spring and summer.
– Include native plants like sages, currants, monkeyflowers, and columbines.
– Select trees and shrubs that offer good cover like sycamores, eucalyptus, pines, and ceanothus.
– Avoid excessive pruning and disturbance around potential nest sites during breeding season.
– Put up a squirrel guard to protect nests in vulnerable locations.
– Keep outdoor cats indoors so they don’t prey on nesting hummingbirds.
– Avoid use of pesticides that reduce insect populations hummingbirds rely on.
– Install a hummingbird nest camera to enjoy the experience without disturbing them.
– Report any nests in risky locations to a wildlife rehabilitator for advice.
With a little planning, you can provide excellent nesting opportunities for Anna’s hummingbirds in your yard! Observing their nesting behaviors and witnessing the raising of tiny hummingbirds is an incredible and rewarding experience.
Frequently Asked Questions
Here are answers to some common questions about Anna’s hummingbird nesting:
How long does it take an Anna’s hummingbird to build a nest?
Nest construction takes 5-10 days from start to completion. The female gathers materials and meticulously weaves everything together into the compact cup shape.
How many broods do Anna’s hummingbirds raise per year?
Anna’s hummingbirds typically raise 2-3 broods per year. They will re-nest and lay more eggs even before the first brood fledges.
Do Anna’s hummingbird nests survive winter weather?
No, the small nests do not endure harsh winter conditions. Nests are ephemeral structures just robust enough to endure until nestlings fledge.
Do male and female Anna’s hummingbirds share nesting duties?
No, male Anna’s hummingbirds do not assist with nest building, incubating eggs, or feeding nestlings. The female takes on all those duties herself.
Do hummingbirds reuse the same nest?
Most hummingbirds do not reuse an intact nest. However, they frequently build a new nest near a prior one, recycling bits of the old nest into the new one.
How often do mother hummingbirds feed their babies?
Mother hummingbirds make frequent feeding visits to the nest, up to every 5-10 minutes all day long. It takes a lot of energy to fuel fast-growing chicks.
Why do hummingbird nests fall apart in the rain?
The exposed tops of the tiny nests allow rain to seep in. As nests get weighed down by moisture, wind can more easily tear them apart. Sturdy anchoring and woven spider silk helps minimize damage.
How do you identify an Anna’s hummingbird nest?
Look for a 3-4 inch wide cup nest bound with spider silk and camouflaged with lichens on an outer branch. Watch to see a green-backed female with a pink crown visit it repeatedly.
Conclusion
Anna’s hummingbirds are resourceful little birds capable of building ingenious nests adapted to their particular breeding needs. By selecting trees and sites with protective cover, anchor points, and nest materials, they engineer compact but expandable abodes to raise their tiny chicks. While weather and predators pose constant threats, nesting Anna’s hummingbirds demonstrate remarkable resilience. By understanding their nesting ecology and taking steps to create a welcoming habitat, we can support success for these captivating birds in our own backyards. Watching their nesting behaviors and chick rearing activities provides an unforgettable connection with nature.