Where Do Hummingbirds Go in the Winter?

It’s so hard to imagine how a bird that weighs as little as a few pennies can withstand a cross-country migration that people have invented myths to explain it. According to one particularly amusing theory, hummingbirds hitch a ride on the wings of Canada Geese. Early cultures in northern Mexico believed that hummingbirds dry up on tree branches for the winter, like little cocoons, until spring rains brought them back to life.

In reality, most breeding hummingbirds in the United States—of which there are roughly 15 species—undertake the same grueling north-south migrations taken by much larger birds each winter. And while the above myths aren’t true, the migration of a hummingbird can seem, at times, inconceivable. Hummingbirds double their body weight in preparation for their journeys. They can fly hundreds of miles in a single day without stopping to rest or feed. And despite never learning the route from their parents, they somehow tread the same paths with incredible fidelity: Banded hummers have been spotted in the same yards year after year.

The Long-Haulers

When winter comes, the majority of hummingbird species “just completely get out of Dodge,” says Sheri Williamson, ornithologist and author of A Field Guide to Hummingbirds of North America in the Peterson Field Guide Series. They fly hundreds or even thousands of miles from their breeding grounds in the northern United States and Canada down to Mexico and even as far as  Central America, joining dozens of other hummingbird species that reside year-round. Scientists estimate that the whole journey takes two to three weeks, depending on how many stops they take along the way.

Two hummingbird species deserve special recognition for their long-distance feats. While some fly over land through Texas, many Ruby-throated Hummingbirds—the only hummingbird that breeds east of the Mississippi River—opt instead to take the 500-mile trip across the Gulf of Mexico. “There's stories of them landing on boats,” says Jason Courter, an avian biologist at Malone University in Canton, Ohio. “I've heard anecdotally of them getting within a couple hundred meters of the shore and then falling dead into the water, because they ran out of their fuel.”

Then there’s the Rufous Hummingbird. Ranging from the Pacific Northwest up through Western Canada and into Alaska, the most northern Rufous populations travel roughly 3,900 miles from their nests in Alaska to their winter home in Mexico. Given that the Rufous is only just over three inches long, that distance is equivalent to over 78 million body lengths, making it one of the longest migrations of any bird in the world in proportion to body size. Compare that to the 13-inch Arctic Tern, which flies over 11,000 miles, and yet a mere 51 million body lengths.

The Short-Distance Travelers

Some hummingbirds in the Southwest, like the Violet-crowned Hummingbird and Rivoli’s Hummingbird, stick to much shorter distances, leaving the sunny southern United States for slightly sunnier Mexico. If they get that far: Recent research suggests that hummingbirds are spending the winter in the United States in greater numbers than in the past. That’s likely because warming temperatures are causing some species’ ranges to move northward, Courter says.

Destinations can vary even within species. For instance, the Broad-billed Hummingbird typically migrates from Arizona to Mexico, says Williamson, but a small fraction stays within their breeding range in Arizona. Similarly, Costa’s Hummingbirds in some parts of southern California, Nevada, and Arizona travel a short distance to join year-rounders in nearby parts of California, Arizona, and northern Mexico. And then there’s the Allen’s Hummingbird, which resides along the California coast. Most of these birds migrate from California down to southern Mexico for the winter, but one south-central sub-species opts to stay put for the cooler months.

The Year-Rounders

One U.S. hummingbird species truly hunkers down for the winter, and that’s the Anna’s Hummingbird. In the early 1900s, they lived solely in Mexico and southern California, where summers are dry, hot, and unfavorable; because of that, the species evolved to breed in the milder winter.

Anna’s are “weird,” says Williamson. “They break a lot of rules that we have established in our minds.”

As exotic flowering trees spread up the West Coast over time, Anna’s followed the nectar trail all the way up to British Columbia and even Alaska, where they live year-round. Their large body size makes them relatively cold-tolerant, and the species seems to just be highly adaptable. “They're managing to survive and prosper up there, at least in a limited fashion, in an area where we wouldn't have imagined any hummingbird could survive,” Williamson says.

Some Anna’s partake in small-scale migrations of other kinds. To find warmth, they might move south vertically—that is, decreasing their elevation. And for decades now, populations in southern California have been heading to Arizona to nest in spring and winter. But for the most part, this is one hummingbird that doesn’t just stick around for winter, but thrives in it.