Hummingbirds are small birds known for their rapid wingbeats and vibrant colors. They embark on seasonal journeys, traveling thousands of miles between their breeding grounds and warmer winter habitats. This migratory behavior allows them to thrive by following the availability of nectar and insects.
Timing Their Southern Journey
Hummingbirds begin their southward migration in late summer and early fall, from August to October in North America. The precise timing varies depending on the species and their geographic location. For instance, adult male Ruby-throated hummingbirds, common in eastern North America, can start their journey as early as late July or early August. Most Ruby-throats depart in late August or early September.
Rufous hummingbirds, found primarily in western North America, may start their southward movement even earlier, with some beginning their trip as early as July. They often follow the Rocky Mountains back to Mexico. Younger birds migrate after adults, allowing them time to mature and build fat reserves. The number of hummingbirds migrating south in the fall can be double the number that return in the spring, as it includes all immature birds born that summer.
What Prompts Hummingbirds to Depart?
Hummingbirds initiate migration in response to environmental cues, primarily decreasing daylight hours. This change in photoperiod signals to the birds that it is time to begin their journey south. It prompts physiological changes within them, such as an increased urge to build fat reserves.
The diminishing availability of nectar sources and insects as temperatures cool also contributes to their decision to depart. While hummingbirds can tolerate cooler temperatures, the scarcity of food in northern breeding grounds during winter compels them to seek warmer climates with abundant sustenance. Before migration, hummingbirds consume large amounts of food, gaining 25-40% of their body weight to fuel their long flights.
The Long Flight South
Most North American hummingbirds migrate to Mexico, Central America, or the Caribbean for the winter. Ruby-throated hummingbirds winter in southern Mexico and Central America, including the Yucatan Peninsula.
The Ruby-throated hummingbird’s non-stop flight across the Gulf of Mexico covers approximately 500 miles and takes 18-22 hours. While some choose this direct route, others follow an overland coastal route through Texas and Mexico. Rufous hummingbirds undertake one of the longest migratory trips for their size, covering nearly 4,000 miles from their northern breeding grounds to southern Mexico. During their journey, hummingbirds face challenges such as extreme weather conditions, predators, and the risk of exhaustion.
Preparing for Their Absence
Individuals can support migrating hummingbirds. Keep hummingbird feeders available through the fall, even after most birds have departed. This ensures late migrants or stragglers have access to an energy source as they pass through.
Leave feeders up for about two weeks after the last hummingbird sighting in your area. Clean feeders regularly (every few days) to prevent mold and bacterial growth. Providing late-blooming nectar plants in gardens also offers natural food sources for hummingbirds as they build up reserves for their long flight.