Hummingbirds possess an astonishing metabolism, requiring them to feed nearly constantly. Their reproductive cycle is specialized, involving a solitary female and a male who offers only genetic material to the next generation. The frequency of mating is determined by the strict limits of their breeding schedule and the brief, high-intensity nature of the mating act itself.
The Mating Season and Frequency
The frequency of mating is directly linked to the availability of energy sources, meaning the breeding season aligns with the peak abundance of nectar-producing flowers and small insects. For many species in North America, this period begins in late winter or early spring, such as March in southern regions, and can extend through the summer months. Year-round residents in warmer climates, like the Anna’s Hummingbird, may begin nesting as early as November, capitalizing on the extended resources.
Over the course of a single breeding season, a female hummingbird will typically produce one to three clutches of eggs. She will seek out a male for mating multiple times during the year, with a period of nesting and raising young separating each reproductive event. The actual physical act of copulation is exceedingly brief, often lasting only three to five seconds as the male perches on the female’s back to transfer sperm. Males are polygamous and will attempt to mate with multiple females throughout the season to spread their genes.
Courtship Displays and Aerial Rituals
Before mating, the male must first engage in an elaborate display to demonstrate his fitness, often involving spectacular aerial maneuvers. The most recognizable of these is the pendulum dive, where the male flies upward 50 to 100 feet before plunging down in a steep, U-shaped arc toward the perched female. This dive is executed at extremely high speeds, with some males reaching up to 45 miles per hour as they pass within inches of the female.
This ritual is a synchronized, multi-sensory performance. As the male reaches the bottom of the dive, he times the flash of his iridescent throat feathers, known as the gorget, to coincide with the production of a distinct, non-vocal sound. This sound is often a loud buzz or chirp produced by the specialized fluttering of his tail or wing feathers, and it is delivered in conjunction with the bright color flash. The female assesses the male’s vigor and coordination before deciding whether to accept him as a mate.
Parental Roles and Nesting Responsibilities
The division of labor following the mating act is absolute. The female becomes a solitary parent, taking on all responsibilities for nest construction, incubation, and raising the young. The male immediately moves on to defend his feeding territory and court other females.
The female constructs a tiny, cup-shaped nest, often no bigger than a large thimble, using soft plant down, moss, and fine fibers. She binds this material together with spider silk, which provides elasticity, allowing the nest to stretch as the nestlings grow. She lays a clutch of two eggs, which she incubates for an average of 14 to 20 days. Once hatched, the female feeds the nestlings a protein-rich diet of small insects and nectar through regurgitation until they fledge, typically 18 to 28 days later.