Hummingbirds are a beloved sight in the summer months in Virginia, darting from flower to flower with their unique hovering flight. But come fall, these tiny birds disappear from backyards and gardens across the state. Where do they go when the weather turns cold? Here’s an in-depth look at the migration patterns and winter habits of Virginia’s hummingbirds.
Do hummingbirds migrate?
Yes, most hummingbirds that spend the summer in Virginia migrate south in the fall to escape the cold winter. Ruby-throated hummingbirds are the most common species seen in Virginia, and they make an incredible 500-mile nonstop journey across the Gulf of Mexico to their wintering grounds in Mexico, Central America, and Florida.
Rufous hummingbirds also pass through Virginia during migration and have one of the longest migration routes of any bird, traveling up to 5,000 miles between their Alaskan breeding grounds and winter homes in Mexico. Costa’s hummingbirds are rare vagrants in Virginia but those that show up would migrate south like the others.
Broad-tailed and Calliope hummingbirds are rare sightings in western Virginia during migration and continue heading south and west towards wintering grounds in Arizona, New Mexico and Mexico.
When do hummingbirds migrate from Virginia?
Most ruby-throats start leaving Virginia in August, with numbers peaking in mid-September. However, some stragglers may linger into early October if food sources remain. Rufous hummingbirds pass through Virginia in August and September during southbound migration.
Timing depends on many factors including food availability, weather patterns, and individual health. Young birds hatched that year often migrate south earlier than older, more dominant birds. Females and juveniles tend to migrate before adult males.
What triggers hummingbird migration?
Changing daylight cues, lack of food, and bad weather in the fall prompts hummingbirds’ southern migration. Shortening daylight hours in late summer are the main trigger, signaling to the birds it’s time to depart. Declines in flower nectar, their main food source, also spur the need to migrate.
Cold snaps and frosts that kill flowers further reinforce it’s time to leave. Some hummingbirds may get caught in a storm system that blows them south prematurely. Overall, instincts honed over thousands of years drive these tiny birds to embark on their epic migratory journeys each fall.
What route do they take?
Ruby-throated hummingbirds take different eastbound and westbound routes in their loop migration each year:
- Southbound in fall: Most fly across the Gulf of Mexico from the U.S. Gulf Coast, a 500-mile nonstop trip taking 18-22 hours.
- Northbound in spring: They follow an overland route, stopping to rest and refuel during the day, heading towards breeding grounds.
Their migration forms a loop spanning the eastern half of the U.S. and into Mexico and Central America for winter. Rufous hummingbirds migrating through Virginia follow the Appalachian Mountains southwest before fanning out westwards towards the Rockies.
Where do they spend the winter?
In winter, Virginia’s ruby-throated hummingbirds are scattered along the Gulf Coast from Mexico to Florida, and south through Mexico, Belize, Guatemala, and Panama. The majority spend winter in central Mexico and Costa Rica.
Rufous hummingbirds winter primarily in southwestern Mexico and Baja California. Costa’s and other rare species follow a similar route to Mexico and Central America. Broad-tailed hummingbirds winter in southern Arizona and New Mexico, and Calliope hummingbirds in central Mexico.
How do they know where to migrate?
Hummingbirds rely on instincts inherited from prior generations rather than learning migration routes. Even young hatch-year birds can perfectly navigate to winter grounds they’ve never seen. Sensing the magnetic field, using the sun for direction, and orienting off landforms help guide them.
Fat stores fuel their long flights over land and water. Ruby-throats are genetically programmed to find Gulf Coast stopover sites to refuel before flying over the open ocean. Once they reach the Yucatan Peninsula, inborn signals likely direct them to dispersed wintering areas.
Do any hummingbirds stay in Virginia?
Nearly all of Virginia’s summer hummingbirds migrate south for the winter. But a tiny number of rufous and calliope hummingbirds have attempted to overwinter in sheltered gardens with feeders in southwest Virginia.
Most that try to stay perish during cold snaps. Banding records show one rufous hummingbird survived in Roanoke from November to March a few years back. Attempts at overwintering are extremely rare and only tried in the warmest southwest microclimates.
When do they return in spring?
Ruby-throats start arriving back in Virginia as early as mid-March, though most return in April and May. Males precede females by up to two weeks and quickly stake out the best territories. The earliest arrivals may get caught in late snowstorms.
Rufous hummingbirds pass back through on their northbound trek in April and May. Return timing depends on weather, individual health, and competition. Older, healthier males typically return to the same breeding sites earliest.
How do they know to come back to Virginia?
Young hummingbirds returning for the first time likely use clues like the earth’s magnetic field and landscape patterns to return to the general breeding range. Adults have finely tuned mental maps and memory to return to former territories.
Scientists believe they also inherit information on optimal breeding locations, bringing successive generations back to successful spots. This combination of imprinting, memory, and genetics helps guide hummingbirds back hundreds of miles to Virginia each spring.
Conclusion
To survive cold winters, nearly all hummingbirds that brighten Virginia’s summers embark on an incredible migratory journey each fall. Driven by instincts and internal programming, they fly to southern U.S. states, Mexico, and Central America to find food and shelter until warming temperatures invite them to return north. Understanding these tiny birds’ amazing migratory feats gives us even more reason to appreciate them during their brief visits in our Virginia backyards.
