Ruby-throated hummingbirds are one of the most popular and widely recognized hummingbird species in North America. These tiny birds capture the hearts of people across the United States and Canada with their beauty and energetic personalities. Ruby-throated hummingbirds are best known for their annual migration, traveling hundreds or even thousands of miles between their breeding grounds in the United States and Canada to their overwintering grounds in Mexico and Central America. Given their migratory nature, many people wonder exactly when ruby-throats are actively migrating through their area. The short answer is that ruby-throated hummingbirds migrate through most of the United States and southern Canada between August and October during their fall migration south, or between March and May during their spring migration north. However, the exact timing varies depending on the latitude. Let’s take a closer look at when and where ruby-throated hummingbirds migrate.
Fall Migration Timing
Ruby-throated hummingbirds begin leaving their breeding grounds as early as late July or early August. The timing depends on a variety of factors, including the individual bird’s sex and age, competition for food resources, and weather patterns.
| Area | Fall Migration Period |
|---|---|
| Southern Canada and Northern U.S. States | Mid August to Early September |
| Midwestern and Northeastern U.S. States | Late August to Mid October |
| Southeastern U.S. States | Early September to Late October |
As shown in the table above, ruby-throats start migrating south through southern Canada and the northern tier of United States in mid-August. By late October, most ruby-throated hummingbirds have left the U.S. completely and arrived at their wintering grounds. During migration, ruby-throats primarily follow two major flyways – the Atlantic and Central flyways. The Atlantic flyway follows the Atlantic coastline, while the Central flyway bisects the center of the United States.
Spring Migration Timing
Ruby-throated hummingbirds begin their return migration north in February and March. Again, exact timing depends on sex, age, competition, weather, and location.
| Area | Spring Migration Period |
|---|---|
| Southeastern U.S. States | Early March to Early April |
| Midwestern and Northeastern U.S. States | Mid March to Late May |
| Southern Canada | Mid April to Late May |
As shown in the table, the first ruby-throats start arriving in the southern United States in early March. Migration progresses northward through spring, reaching the Canada border by late April or early May. Upon arrival males scout for territories before the females arrive.
What Triggers Migration?
So what signals ruby-throated hummingbirds to begin their epic seasonal journeys? Migration is triggered by a number of environmental cues and changes in physiology. Here are some of the key factors:
- Decreasing daylight – As days get shorter in late summer, hummingbirds take cue to begin migrating south.
- Lack of food availability – The decline of blooming flowers and nectar sources motivates hummingbirds to seek out new feeding grounds.
- Lower temperatures – Cooler temperatures, especially overnight lows, encourage migration to warmer climates.
- Hormones – Changing ratios of sex hormones have been linked to migratory restlessness and motivation to migrate in birds.
- Internal clock – Research shows migratory birds have an internal calendar and body clock that is genetically programmed to cause migratory urges at certain times of year.
Orientation and Navigation
One fascinating aspect of hummingbird migration is their ability to orient themselves and navigate accurately over hundreds or thousands of miles to reach their target destination at the end of migration. Here are some of the amazing ways hummingbirds manage this navigational feat:
- Sun compass – Hummingbirds determine their directional bearing based on the position of the sun.
- Stars – On clear nights, hummingbirds can use star patterns to orient themselves.
- Magnetoreception – Hummingbirds have an internal magnetic compass and can sense the earth’s magnetic fields to determine direction.
- Visual landmarks – Recognizing landmarks like mountains, coastlines, and rivers helps hummingbirds stay on course during migration.
- Smell – Research indicates a hummingbird’s sense of smell helps it navigate by detecting odors from plants, forests, and other land features.
Migration Route and Destinations
Ruby-throated hummingbirds follow set migratory routes year after year. Here are some details on the typical migration paths and wintering grounds used by ruby-throated hummingbirds each season:
Fall Migration Route
During fall migration, ruby-throats exit the United States primarily through two main flyways before merging over the Gulf of Mexico:
- Atlantic Flyway – Follows the Atlantic Coast from Maine to Florida
- Central Flyway – Runs centrally through the Great Plains from Canada to Texas
Once reaching the northern regions of the Yucatan Peninsula and Mexico’s Gulf Coast, the migration paths converge as the birds continue to their various wintering destinations.
Winter Destinations
The winter range for ruby-throated hummingbirds extends from southern Mexico across Guatemala and Belize into El Salvador and Honduras. The three most common wintering regions are:
- Southern Mexico
- Guatemalan Highlands
- Panama Canal Zone
Within these areas, ruby-throats favor tropical forests, woodlands, and scrub habitats. Parts of Costa Rica and Panama represent the southern limits of their winter range.
Spring Migration Route
In spring, ruby-throats follow the same two flyways in reverse from their winter grounds back through the Gulf Coast to breeding areas across the Eastern United States and Canada. Their return journey can cover thousands of miles depending on their starting point in Central America or Mexico.
What Do They Eat Along the Way?
One of the most amazing aspects of hummingbird migration is these tiny birds’ ability to find food over thousands of miles. Ruby-throated hummingbirds have extremely high metabolisms and can starve if they don’t eat sufficient calories every day. Here are some of the main food sources they rely on during migration:
- Tree sap – Hummingbirds tap into sap wells on trees for quick energy.
- Flower nectar – They seek out flowers in bloom along their migration path.
- Feeders – Backyard hummingbird feeders provide critical fueling stops during migration.
- Insects – Hummingbirds get essential protein, calories, and fat by catching small insects.
To conserve energy, ruby-throats often fatten up before crossing major barriers like the Gulf of Mexico, storing extra fat to burn. Some hummingbirds have been known to double their pre-migratory body weight.
Major Threats and Survival
Migrating ruby-throated hummingbirds face many threats and challenges on their journeys, including:
- Habitat loss
- Window collisions
- Predators
- Extreme weather events
- Lack of food
- Communication towers and wind turbines
Research estimates only 30-50% of fledgling hummingbirds survive their first fall migration. However, those that make it to their winter grounds often have higher survival rates for the remainder of winter. Successfully navigating migration is a learned skill.
How to Help Hummingbirds Migrate
Here are some ways you can help provide critical support for migrating hummingbirds in your area:
- Put up new feeders or clean existing ones before migration peaks in your area.
- Use a nectar formula made with cane sugar or beet sugar, not honey.
- Don’t let feeders run dry and change nectar frequently.
- Provide flowering plants that bloom late summer through fall.
- Eliminate pesticides from your garden.
- Keep outdoor lights off at night during migration season.
With a few small actions, you can make a difference for migrating ruby-throated hummingbirds stopping by your yard.
Fascinating Migration Facts
To wrap up, here are few interesting facts about the migration of ruby-throated hummingbirds:
- Ruby-throats have one of the largest migration ranges of all North American hummingbirds.
- Their tiny wings beat up to 53 times per second and allow speeds over 30 mph.
- Some ruby-throats migrate across the Gulf of Mexico, a 500 mile non-stop flight.
- Most ruby-throats migrate alone and not in flocks.
- Young fledglings instinctively know to migrate even without guidance.
- Hummingbirds migrate as far north as Nome, Alaska to breed.
- Southern populations may not migrate at all.
The migration of the ruby-throated hummingbird is an awe-inspiring and complex phenomenon. With the right habitat conservation and support, these resilient tiny travelers will continue their incredible seasonal journey for generations to come.
Conclusion
In summary, ruby-throated hummingbirds migrate over a long window from August through October during fall migration and March through May during spring migration. Migration timing shifts from south to north during these periods as the birds travel between breeding areas and wintering grounds. A variety of environmental triggers and navigational skills guide ruby-throats on their journey along established flyways and over obstacles like the Gulf of Mexico. With proper habitat and key refueling spots provided, these tiny birds can successfully complete their huge migratory journey year after year. Their migration is one of nature’s most phenomenal events.
