As cooler temperatures arrive, hummingbirds vanish from gardens and feeders. These tiny, iridescent birds, a common sight during warmer months, seem to disappear with the change of seasons. Their absence often sparks curiosity about where they go and how they survive the colder months.
The Annual Migration
Hummingbirds undertake remarkable long-distance journeys each year, driven by environmental changes. Decreasing daylight hours in late summer and fall, alongside the scarcity of flowering plants and insects, signal the time for migration. These tiny birds embark on journeys spanning hundreds or even thousands of miles. To prepare for this demanding feat, hummingbirds significantly increase their food intake, gaining 25-40% of their body weight to build fat reserves for energy. They typically fly alone, often following the same routes they have traveled in previous years.
Key Winter Destinations
Most North American hummingbirds spend winters in warmer climates, primarily Mexico and Central America. The Ruby-throated Hummingbird, common in the eastern United States, often travels to southern Mexico and Central America, including Panama, undertaking a non-stop flight of about 500 miles across the Gulf of Mexico. Western species like Rufous Hummingbirds, breeding as far north as Alaska, typically winter in southern Mexico. Black-chinned and Broad-tailed hummingbirds commonly find their winter homes in western and southwestern Mexico, with some Broad-tailed populations extending into Guatemala and Belize. While most head to these tropical regions, an increasing number of species overwinter in the southernmost United States, particularly along the Gulf Coast and in parts of California and Arizona.
Surviving the Cold Months
Upon reaching their wintering grounds or during cold spells, hummingbirds employ torpor, a state of reduced metabolic activity that helps them conserve energy. During torpor, their heart rate, breathing, and body temperature drop significantly. This deep, sleep-like state allows them to survive periods when food is scarce or temperatures are low, often occurring nightly. Hummingbirds rely on nectar from flowering plants and small insects for their diet, as winter habitats provide necessary food sources. When emerging from torpor, they rapidly increase heart and breathing rates, using muscle vibrations to warm their bodies.
Hummingbirds That Stay
While most hummingbirds migrate, certain populations and species remain in cooler climates year-round, such as the Anna’s Hummingbird, which commonly resides through winter along the Pacific Coast, from California northward into British Columbia and even Alaska. These birds have adapted to cooler temperatures, utilizing natural food sources and human-provided feeders. Anna’s Hummingbirds supplement their diet with sap from woodpecker holes and a higher quantity of insects. Their nightly torpor is key to surviving cold temperatures. The expansion of their range northward has been linked to exotic flowering trees and urban environments, providing consistent food sources, and other species like Rufous, Black-chinned, and Allen’s hummingbirds are also increasingly observed overwintering in parts of the southern United States.