Hummingbirds, known for their small size and rapid wingbeats, are remarkable creatures. Their ability to hover and dart captivates observers, but their nesting and reproduction process is equally fascinating. These tiny birds construct delicate homes, showcasing impressive instinct and architectural ingenuity from site selection to raising young.
Choosing the Nest Site
Female hummingbirds alone select a nest site, prioritizing concealment and protection. Nests are typically in trees, shrubs, or dense bushes, often on a slender, descending branch or within a fork. These sites are usually elevated, ranging from 10 to 90 feet above the ground, though many are found between 10 to 40 feet high.
Hummingbirds prefer various tree species, including fir, pine, oak, cottonwood, sycamore, hornbeam, birch, poplar, and hackberry, for their suitable foliage. Strategic placement beneath leaves protects the nest from rain and hides it from above. While natural vegetation is typical, nests have been found in unusual spots like wires, clotheslines, or light fixtures, demonstrating their adaptability.
Building the Tiny Home
Once a suitable location is identified, the female hummingbird begins constructing her nest, a process that can take up to seven days. This miniature home is a small cup, resembling a ping-pong ball or walnut, measuring about 2 to 2.25 inches in diameter and less than 2 inches deep. The nest is meticulously woven from soft, flexible materials.
Common building materials include plant down (such as thistle or dandelion), moss, small twigs, and bits of leaves. Spider silk provides the nest’s remarkable strength and elasticity, binding materials and allowing it to stretch as young grow. The exterior is camouflaged with compacted green lichen or bark, making the nest blend seamlessly with its surroundings and appear like a natural knot on a branch.
The Eggs and Hatchlings
Within this carefully crafted nest, the female hummingbird typically lays two tiny, white eggs. These eggs are remarkably small, comparable in size to a jelly bean, coffee bean, or navy bean, usually measuring around 0.5 to 0.6 inches in length. The female is solely responsible for incubating the eggs, a period that usually lasts between 14 to 21 days, with Ruby-throated hummingbirds often hatching after 15 to 18 days. She sits on the eggs almost constantly, leaving only for brief foraging trips to maintain warmth.
Newly hatched hummingbird chicks are vulnerable. They emerge from their eggs naked or with only sparse gray down, their eyes closed, and are helpless. These pink or gray-skinned hatchlings are very small, weighing less than a gram, or even less than a dime. The mother feeds them a high-protein diet of small insects and spiders for rapid growth and development.