Hummingbirds are remarkable little birds that capture the imagination with their diminutive size, iridescent colors, and ability to hover in midair. These characteristics have endeared them to people worldwide. Hummingbirds are found only in the Western Hemisphere, with most species occurring from Alaska to Chile.
One of the most fascinating aspects of hummingbirds is their migratory behavior. Hummingbirds that breed in the United States and Canada migrate south in the fall to spend the winter in Mexico, Central America, and the Caribbean Islands. Some hummingbird species, such as Anna’s and Rufous Hummingbirds, migrate relatively short distances, while others, like the Ruby-throated Hummingbird, may migrate across the Gulf of Mexico.
Not all hummingbirds migrate. Tropical and subtropical species are mostly nonmigratory. Allen’s, Costa’s, and other Central American hummingbirds stay put throughout the year. Meanwhile, South American species may move locally based on food resources but generally do not make long migrations.
Why do hummingbirds migrate? What routes do they take? When do they begin their journey, and how do they know when to start? Where do different hummingbird species spend the winter? This article explores the fascinating migratory behavior of hummingbirds in detail.
Why Do Hummingbirds Migrate?
Hummingbirds migrate to take advantage of seasonal food resources. The majority of hummingbird species breed during spring and summer in North America when flowers are in bloom and insect prey is abundant. As winter approaches, many flowers fade and insects become scarce. To survive, hummingbirds must seek out new habitat with adequate food supplies.
By migrating, hummingbirds escape harsh weather conditions in their northern breeding range. Freezing temperatures and snowstorms make it challenging for hummingbirds to survive winter in most of the United States and Canada. Lack of adequate food only compounds the problem. Migrating allows hummingbirds to survive winter in warmer climates where flowering plants and insects remain plentiful year-round.
Key Reasons Hummingbirds Migrate
- Lack of food in the breeding range during winter
- Escape harsh weather and freezing temperatures
- Take advantage of warm climates with year-round food sources
What Routes Do Hummingbirds Take?
Hummingbirds follow established migration routes known as flyways. These routes take advantage of geographical features like mountain ranges and coastlines that provide navigation cues during migration. Hummingbirds may migrate solo or in loose flocks, in both cases following the flyway for their species. Here are some of the main hummingbird migration flyways:
Western Flyway
Hummingbirds that breed in the western United States and Canada, such as Rufous and Allen’s Hummingbirds, migrate south along the Pacific Coast. Their migration route follows the Sierra Nevada mountain range in California. Some birds cross the Gulf of California to winter in mainland Mexico while others follow the mountains all the way to Mexico’s southern tip.
Central Flyway
The Central Flyway closely tracks the Rocky Mountains and the Great Plains. Ruby-throated, Black-chinned, Broad-tailed, and other hummingbirds use this route to migrate from the interior western and central United States to Mexico and Central America.
Mississippi Flyway
Hummingbirds breeding in eastern and central North America migrate along the Mississippi River valley. At the Gulf of Mexico, most cross the 500-mile open water, arriving at the Yucatan Peninsula before continuing to Central America.
Atlantic Flyway
A small number of vagrants use the Atlantic coastline to migrate south. Rufous Hummingbirds have been documented following this route from New England to Florida and the Caribbean.
When Does Hummingbird Migration Begin?
Hummingbirds carefully time their migration to match the blooming of flowers along their route. This ensures they have adequate food supplies to fuel their long journeys. Here are the factors that determine when hummingbirds migrate in the fall:
Photoperiod
In late summer, the shortening amount of daylight provides a cue to start physiologically preparing for migration. Hummingbirds increase their body fat as fuel for the journey ahead.
Lack of Food
As flowers begin to fade and die back in fall, food becomes scarce for hummingbirds still in their northern breeding grounds. Dwindling food supplies prompt them to migrate south.
Weather
The arrival of cold snaps and storms motivates hummingbirds to depart on migration before conditions deteriorate further. Sudden drops in temperature often precede mass migration events.
Internal Clock
Hummingbirds appear to have an internal clock that contributes to the timing of migration. Even in artificially maintained ideal conditions with abundant food, hummingbirds become restless when their internal clock says it’s time to migrate.
| Species | Migration Departure Timeframe |
|---|---|
| Ruby-throated Hummingbird | Early August to early September |
| Rufous Hummingbird | Mid-June to late August |
| Allen’s Hummingbird | Early July to late August |
| Calliope Hummingbird | Mid-July to late September |
As this table shows, different hummingbird species migrate at slightly different times in fall depending on their breeding range. However, most initiate migration sometime between mid-summer and early fall.
Where Do Hummingbirds Spend the Winter?
During winter, different hummingbird species occupy distinct wintering grounds centered in areas providing plentiful food. Here are the main wintering destinations for hummingbirds that breed in the United States and Canada:
Mexico
Coastal Mexico is a winter haven for Anna’s, Costa’s, Rufous, Allen’s, and other western hummingbirds. Pine-oak forests in the mountains and tropical vegetation along the coasts provide nectar-rich flowers throughout winter.
Southern Mexico and Guatemala
The tropical dry forests of southern Mexico and northern Central America host wintering Calliope, Broad-tailed, Black-chinned, and Rufous Hummingbirds. Flowers like poinsettia and turk’s cap provide essential food.
Panama
Lush lowland rainforests in Panama provide ideal winter habitat for Ruby-throated Hummingbirds. Panama marks the southern limit for most Ruby-throats, although some may continue to Colombia and Venezuela.
Costa Rica and Nicaragua
With abundant flowering plants, Costa Rica and Nicaragua attract wintering Rufous, Allen’s, and other western hummingbird species. Some Black-chinned and Calliope Hummingbirds also spend winter in these countries.
| Species | Wintering Ground |
|---|---|
| Ruby-throated Hummingbird | Panama, Costa Rica, Nicaragua |
| Rufous Hummingbird | Mexico, Central America |
| Allen’s Hummingbird | Mexico, Central America along the Pacific Coast |
| Calliope Hummingbird | Mexico, Central America |
This table summarizes the wintering grounds for some of the most common hummingbird species breeding in North America.
Unique Aspects of Hummingbird Migration
Hummingbird migration stands out for a number of reasons:
Extremely Long Journeys
For their tiny size, hummingbirds migrate astonishingly long distances. The diminutive Ruby-throated Hummingbird breeds across eastern North America but flies 500 miles nonstop across the Gulf of Mexico in fall. This journey represents a 2,000 mile round trip migration for many individuals.
Rapid Pace
Hummingbirds don’t dawdle on migration. Instead, they travel remarkably quickly to minimize time spent on the wing. Ruby-throated Hummingbirds may cover over 25 miles per hour while migrating. With ideal tailwinds, they can fly up to 50 miles per hour.
Fat Storing Champions
Pre-migratory fattening allows hummingbirds to store enough energy to cross barriers like the Gulf of Mexico. Incredibly, Ruby-throated Hummingbirds may double their body weight prior to migration, developing fat levels exceeding 30% of total weight.
Navigator Extraordinaire
Hummingbirds precisely navigate their migration routes year after year. Landmarks, the position of the sun, and a magnetic compass all likely aid orientation during migration. Young birds migrate solo on their first journey by following genetic migration programs imprinted on their brains.
Tough Crossings
Hummingbirds embark on some of the most grueling migrations in the animal kingdom. For example, southbound Ruby-throats fly 500 miles nonstop across the Gulf of Mexico at a stretch. Rufous Hummingbirds also make a harrowing ocean crossing, this time from Alaska to British Columbia on their return to the breeding grounds each spring.
Threats During Migration
Migrating hummingbirds face substantial challenges including:
Lack of Food
Finding adequate food is a persistent problem during migration. Sudden cold snaps can cause flowers to die back faster than expected.Hummingbirds risk starvation if they cannot find enough refueling stops.
Inclement Weather
Storms, wind, and rain jeopardize hummingbirds during migration. Cold fronts are especially dangerous when crossing the Gulf of Mexico. Hurricanes may blow hummingbirds far off their normal course.
Predators
During migration, hummingbirds are vulnerable to predators they may not encounter in their breeding areas. Hawks, falcons, and gulls take a heavy toll on migrating hummingbirds.
Habitat Loss
Urbanization and development destroys natural habitat hummingbirds rely on for food and shelter during migration. Loss of forests and meadows along flyways further threatens migrating hummingbirds.
How to Support Migrating Hummingbirds
Here are some ways you can help provide resources for hummingbirds migrating through your area:
Plant Native Flowers and Trees
Landscape with native nectar plants that bloom late summer through fall. Trumpet vine, turtlehead, cardinal flower, and sage provide excellent fuel sources.
Supply Feeders
Stock up on hummingbird feeders and keep them freshly filled, especially during peak migration. Use a nectar mix of 1 part sugar to 4 parts water.
Provide Water
Ensure fresh, clean water sources like misters, drippers, and small pools to allow hummingbirds to bathe and hydrate.
Limit Pesticide Use
Avoid using pesticides that reduce insect populations critical to migrating hummingbirds. Supply other food instead like trees where aphids abound.
Report Band Sightings
If you spot a banded hummingbird, note the band number and color, then promptly report it to the Bird Banding Laboratory. This helps scientists track migration routes.
The Extraordinary Migration of Hummingbirds
For centuries, people marveled at the mysterious disappearance of hummingbirds each fall. Scientists now understand these tiny birds embark on incredible migrations covering thousands of miles. The long journeys of hummingbirds represent one of nature’s great wonders.
Hummingbirds migrate to escape harsh weather and seek out the resources needed to survive. By traveling vast distances along established flyways, hummingbirds follow a genetic migration script imprinted on their brains. Their remarkable navigational abilities guide them to winter homes offering the food and shelter required to sustain hummingbirds until conditions improve the following spring.
The migratory feats of hummingbirds rank among the most astounding in the animal kingdom. Understanding their migration cycle allows us to better support these fascinating creatures on their annual odysseys.
