The Anna’s hummingbird (Calypte anna) is a small, colorful hummingbird found along the Pacific Coast of North America. Both male and female Anna’s hummingbirds have slender, medium-length beaks that allow them to feed on nectar from flowers. Their beaks have evolved for reaching into tubular flowers and drinking nectar.
Beak Structure
The Anna’s hummingbird has a long, slender beak that curves slightly downward. The beak length from the tip to where it attaches to the skull is typically around 2 centimeters (0.8 inches) long. The upper and lower mandibles of the beak are tapering and pointed to allow the bird to plunge its beak into flowers.
The hummingbird’s beak is an elongate, tapered tube well-adapted for drinking nectar from flowers. It has a specialized tongue that extends past the tip of the bill to lap up liquid. The tongue has forked tips which match the shape of nectar tubes in flowers.
The upper mandible of the beak overlaps the lower mandible. Both the upper and lower mandibles have thin keratin sheaths covering bony cores. Keratin is the same material that makes up human fingernails. This covering gives the beak strength and flexibility.
Inside the beak, the tongue of the Anna’s hummingbird is forked to match the shape of nectar tubes in flowers. When feeding, the bird plunges its beak deep into the flower and uses its forked tongue to lap up nectar.
Beak Color
The beak of both male and female Anna’s hummingbirds is mostly black. The upper mandible has a reddish-pink base in adults of both sexes. The very tip of the beak is black.
Young fledgling Anna’s hummingbirds have a dark beak without the reddish-pink base. The red color at the base develops as the birds mature.
Beak Function
The Anna’s hummingbird’s beak allows it to feed on liquid nectar from tubular flowers. Its slender shape matches the long shape of nectar-holding floral tubes.
Some key functions of the Anna’s hummingbird’s specialized beak include:
- Reaching deep into tubular flowers to access nectar
- Lapping up nectar using its forked tongue
- Grasping insects and spiders out of the air
- Constructing its delicate nest
In addition to nectar feeding, the Anna’s hummingbird will opportunistically catch small insects in flight. The tip of its beak helps snap up insects. Its beak is also used in gathering plant down and spider silk to weave together its tiny nest.
Differences From Other Hummingbirds
There are over 300 different species of hummingbirds throughout the Americas. While their beaks share some common adaptations, there are differences between species.
Some ways the Anna’s hummingbird’s beak differs from other hummingbirds include:
- Longer and more slender than thicker-billed hummers like bee and mountain mango hummingbirds
- Intermediate in length and curvature compared to the very decurved beaks of sapphire-spangled hummingbirds and the short straight beaks of Scintillant hummingbirds
- All black color unlike the brightly colored rainbow-hued beaks of some Brazilian hummingbird species
These differences allow the Anna’s hummingbird to feed on specific flower types adapted to its beak structure. The beaks of different hummingbird species have evolved to match different flower shapes in their habitats.
Beak Adaptations
The Anna’s hummingbird’s slender beak is exquisitely adapted for feeding on nectar from tubular flowers. Specific adaptations include:
- Length – Long enough to reach nectar at the base of long, narrow flower tubes
- Curvature – Slight downward curve at tip allows the beak to probe into flowers
- Tapered shape – Slender, pointed bill easily inserted into openings
- Overlapping mandibles – Allow precision handling of insects and nest materials
- Forked tongue – Tongue tip matches shape of nectar tubes for nectar extraction
- Keratin covering – Gives rigidity but some flexibility to the beak
These specialized features allow the hummingbird to access food sources that other birds cannot. This includes nectar deep within curved, tubular flowers. The match between beak structure and flower shapes reflects their coevolution.
Role in Feeding
The Anna’s hummingbird’s beak allows it to feed in two main ways:
- Drinking nectar from flowers – The hummingbird can insert its beak into tubular flowers to drink nectar. Its forked tongue laps up the nectar.
- Catching insects – The hummingbird uses its tapered, pointed beak to snap up small flying insects.
Nectar from flowers provides the Anna’s hummingbird with quick energy from sugars. Small insects provide supplemental protein. The traits of its beak allow the hummingbird to access both food sources.
Role in Nest Building
Anna’s hummingbirds construct tiny, cup-shaped nests out of plant down held together by spider silk and bits of bark. To build its nest, the hummingbird uses its beak to:
- Collect plant down, spider silk, and other materials
- Transport these materials to the nest site
- Precision weave the materials together to form the nest structure
The hummingbird uses its long, pointed beak to neatly tuck materials into place around the nest. The overlapping mandibles allow it to grasp and place materials with great dexterity.
Comparison to Bee Hummingbird
| Feature | Anna’s Hummingbird | Bee Hummingbird |
|---|---|---|
| Length | 2 cm | 1.9 cm |
| Width at Base | 0.5 cm | 0.4 cm |
| Curvature | Slight downward curve | More strongly decurved |
| Color | Black with pale pink base | Black |
| Adaptations | Intermediate length, moderate curvature | Very short, strongly curved |
This table compares the beak characteristics of Anna’s and bee hummingbirds. The bee hummingbird has the smallest beak of any bird species. Its shorter, more curved beak allows it to feed on flowers with very short, curved corollas.
Conclusion
The Anna’s hummingbird has a slender, moderately curved beak adapted for feeding on the nectar of tubular flowers. Its tapered shape, forked tongue, and mandibular structure allow it to readily lap up liquid nectar from flowers. The beak also aids in insect capture and nest construction. Compared to other hummingbirds, the Anna’s hummingbird’s beak is intermediate in size and curvature.
