Hummingbirds are known for their diminutive size, yet their nests are an impressive feat of natural engineering. These structures are among the smallest and most difficult to locate homes built by any bird in the Americas. The female constructs this tiny vessel alone, transforming natural fibers into a carefully designed nursery that protects delicate eggs and accommodates rapidly growing young.
Size, Shape, and Structural Integrity
The hummingbird nest is typically a compact, deep cup, comparable to the size of a large thimble or half a walnut shell. It measures approximately 1.5 to 2 inches in diameter, just enough space for the female to incubate her clutch of two eggs. The cup shape and dense, velvety texture provide excellent insulation and protection from the elements.
The nest’s elasticity is crucial for raising young. The sides of the cup are designed to stretch vertically and horizontally as the nestlings grow larger. This flexibility allows the nest to double in size without collapsing or losing structural integrity. The floor is often spongy, which helps absorb movement and provides a soft foundation for the developing chicks.
Construction Materials and Camouflage
The hummingbird’s construction materials are chosen for strength, flexibility, and appearance. The foundation and binding agent of the structure is almost always spider silk, which the female collects from nearby webs. This silk acts as a powerful, flexible adhesive, securing the other materials together and anchoring the nest to its chosen branch.
The interior of the nest is lined with soft plant down, often gathered from the seeds of dandelions, cattails, or cotton-like materials. This soft lining provides excellent insulation to keep the eggs and hatchlings warm. The exterior is camouflaged to achieve near-perfect concealment.
Female hummingbirds cover the outside of the nest with small flakes of lichen and moss, which are pressed firmly into the sticky spider silk. This makes the nest blend seamlessly with the tree bark or branch where it is attached. The finished product often looks like a natural, moss-covered knot or a small, irregular bump on the wood. This visual disguise is the primary defense mechanism against potential predators.
Common Nest Locations and Identification
Hummingbirds prioritize shelter, safety, and proximity to food sources when choosing nesting sites. The nest is typically built on a thin, downward-sloping branch, frequently placed near a fork or joint in the wood for added support. Most nests are located between 10 and 40 feet off the ground, often high enough to deter many ground predators.
Nests are commonly found in trees like oak, poplar, or hackberry, or within dense shrubs that offer a protective canopy. In urban and suburban settings, the female may choose sheltered, human-made structures, such as clotheslines or utility wires. The most reliable way to identify a nest is to look for the camouflaged, greenish-gray, cup-shaped growth on the side of a branch. Observing the female’s repeated movements to a specific spot can also reveal the location of this hidden nursery.