Hummingbirds are some of the most fascinating birds found in North America. Their tiny size, lightning-fast wings, and ability to hover like helicopters make them a joy to watch. One of the most intriguing things about hummingbirds is their amazing migration. Each fall, several species of hummingbirds undertake incredible journeys between their summer breeding grounds in North America and their winter homes in Mexico, Central America, and the Caribbean. Understanding where each species goes and how they get there reveals the remarkable resilience of these tiny migrants.
What hummingbird species migrate?
Of the 17 species of hummingbirds found regularly in North America, 7 undertake a yearly migration. These include:
- Ruby-throated Hummingbird
- Black-chinned Hummingbird
- Anna’s Hummingbird
- Rufous Hummingbird
- Allen’s Hummingbird
- Calliope Hummingbird
- Broad-tailed Hummingbird
The remaining hummingbird species, such as the Buff-bellied Hummingbird and Blue-throated Hummingbird, reside year-round in the southern United States, Mexico, and points south. They may migrate short distances but do not make the massive seasonal journey their migratory relatives undertake.
Why do hummingbirds migrate?
Hummingbirds migrate for a simple reason – to find abundant sources of food and suitable places to breed. During the summer, many species of hummingbirds take advantage of the seasonal bloom of flowers and abundance of insects in the temperate climates of Canada and the northern United States. But once winter arrives, the nectar-rich blossoms disappear and freezing temperatures make survival difficult.
To escape these harsh conditions, hummingbirds fly south to warmer tropical regions rich in flowers and insects. Spending winter around places like Costa Rica and Mexico allows hummingbirds to find enough food to sustain themselves during the cold season. Come spring, the urge to breed drives them back north again.
Where do the major migratory hummingbird species winter?
While overwintering grounds are scattered across Mexico, Central America, and the Caribbean, each migratory hummingbird species tends to have a core wintering area:
Ruby-throated Hummingbird
The Ruby-throated Hummingbird nests farther east than any other hummingbird, breeding throughout eastern North America. In winter, most migrate to southern Mexico and Central America. Southern Mexico, particularly the Yucatan Peninsula, hosts the majority of wintering Ruby-throats. Costa Rica and Belize also provide overwintering grounds.
Black-chinned Hummingbird
This western hummingbird breeds across the southwestern United States and winters primarily in Mexico. The Mexican states of Sinaloa, Jalisco, Guerrero and Oaxaca see the bulk of the wintering Black-chins, mainly along the Pacific Coast. Some also winter in Baja California.
Rufous Hummingbird
The feisty Rufous Hummingbird nests farther north than any other, breeding in northwest North America from Alaska to Oregon. While some winter along the Gulf Coast, most fly to the warm, flower-filled forests of southern Mexico. The inland mountainous states of Guerrero and Oaxaca host huge numbers of overwintering Rufous Hummingbirds.
Allen’s Hummingbird
This species breeds along California’s coast and winters in a relatively small region centered around Mexico’s Baja Peninsula. Coastal Sinaloa and Guerrero attract some Allen’s as well, but Baja appears to be this species’ core winter home.
Calliope Hummingbird
Calliope Hummingbirds breed in mountain meadows as far north as British Columbia before migrating to the highlands of central Mexico for winter. The mountain pine and fir forests of Michoacán, Guerrero and Oaxaca provide ideal overwintering habitat.
Broad-tailed Hummingbird
True to its name, this species nests across the broad expanse of the western United States, from New Mexico to Wyoming. It migrates south along the spine of the Rocky Mountains to winter primarily in the central Mexican highlands. Zacatecas, San Luis Potosí, Guanajuato and Jalisco all host large numbers of wintering Broad-tailed Hummingbirds.
Anna’s Hummingbird
Unlike its migratory relatives, Anna’s Hummingbirds are expanding their breeding range northward, and some birds now overwinter in the relatively balmy Pacific Coast region. Those that do migrate head to western Mexico. Scattered groups winter in inland states like Jalisco and Guerrero, but Baja California and mainland coastal areas like Sinaloa host the biggest wintering populations.
What routes do they follow?
The diverse geography of North America dictates that migrating hummingbirds follow different pathways both to and from their wintering grounds. However, several key routes emerge:
Ruby-throated Hummingbird
Ruby-throats have the longest migration of any New World hummingbird, as most fly across the Gulf of Mexico between the Yucatan Peninsula and the Gulf Coast of the United States. Their route forms a giant loop:
- Fall: Breeding areas in eastern North America to Gulf Coast to Yucatan Peninsula to Central America
- Spring: Central America to Yucatan to Gulf Coast to breeding grounds
Western Species
Hummingbirds that nest in western North America, like Black-chins and Rufous, follow the spine of mountain chains on their push south:
- Fall: Breeding regions to Rocky Mountains to Sierra Madre Oriental mountains into Mexico’s interior highlands
- Spring: Highlands of Mexico back up the Sierra Madre Oriental and Rocky Mountains to breeding grounds
Species like Allen’s Hummingbirds along the California coast simply cross the mountains into Baja California and coastal Mexico.
Calliope Hummingbird
On their way to and from Mexico’s highlands, Calliope Hummingbirds take a route through Arizona and New Mexico, tracing the contours of mountains and river valleys.
How do they navigate their migrations?
The journeys hummingbirds make each year cover thousands of miles, often over areas where nectar and insect prey are scarce. Their tiny bodies seem hardly built for such epic flights over mountains and across huge expanses of desert and ocean. However, hummingbirds have specialized abilities and tactics that allow them to migrate extreme distances remarkably well:
Internal Compass
Experiments indicate hummingbirds (and other migratory birds) may get their sense of direction from the Earth’s magnetic field. They have deposits of the mineral magnetite in their head that detect subtle shifts in the planet’s magnetic fields. These act like tiny compasses guiding the birds along their migratory routes.
Mental Maps
Hummingbirds also appear to have mental maps hardwired into their brains that contain information about key stopover points and migratory routes. First-year birds somehow know to travel to traditional wintering sites they have never visited. This implies some sort of innate migratory instruction set passed down genetically.
Ability to Put on Fat
Hummingbirds have the remarkable ability to quickly gain substantial fat reserves from rich food sources. In just a day or two of gorging, they can nearly double their body weight, adding critical fuel for migratory flights.
Flying High
To travel over inhospitable areas like the Gulf of Mexico, hummingbirds fly at surprisingly high altitudes up to 5,000 feet. Here, favorable winds help push them along, temperatures are cooler, and the air contains more oxygen (critical for their supercharged metabolisms).
Torpor
To survive nights when they cannot find food, hummingbirds employ an energy-saving tactic called torpor. Their metabolic rate drops to a fifteenth of normal and body temperature falls as much as 60 degrees Fahrenheit. This hypothermic-like state reduces their energy needs by an incredible 98%, allowing tiny fat reserves to stretch much further.
Major Stopover Sites
While some hummingbirds make the trip south in one long haul, most break up their journey at key stopover sites to rest and refuel. These migratory hotspots – scattered along the Gulf Coast, Mexico’s mountains, and Central American coasts – provide abundant food at critical junctures of the perilous migratory journey:
| Stopover Site | Notable Features | Key Species | |
|---|---|---|---|
| Texas Gulf Coast | Diverse gardens and flowering trees in urban areas along coast | Ruby-throated Hummingbird | |
| Northern Mexican Interior Highlands | Pine-oak woodlands rich in flowers | Rufous Hummingbird, Calliope Hummingbird, Broad-tailed Hummingbird | |
| Mountains of Oaxaca, Mexico | Pine and fir forests with abundant blooms | Black-chinned Hummingbird, Calliope Hummingbird, Broad-tailed Hummingbird, Rufous Hummingbird | |
| Chiapas, Mexico | Rainforests and gardens full of nectar plants | Ruby-throated Hummingbird | |
| Veracruz, Mexico | Coastal gardens and citrus groves | Ruby-throated Hummingbird | |
| Southern Mexico: | Michoacán, Guerrero, Oaxaca | Mixture of pine forests, gardens, and scrub | Anna’s Hummingbird, Costa’s Hummingbird, Calliope Hummingbird, Broad-tailed Hummingbird, Rufous Hummingbird, Black-chinned Hummingbird |
| Guanacaste, Costa Rica | Lowland dry forests rich in flowers | Ruby-throated Hummingbird, Rufous Hummingbird |
Noteworthy Migratory Spectacles
Some of these migratory stopovers turn into incredible super-concentrations of hummingbirds that rank as true natural wonders:
- Cape May Point, New Jersey – Over 1,000 Ruby-throated Hummingbirds per hour may pass this tip of the New Jersey coast in fall as birds prepare to cross the Atlantic.
- Ramsey Canyon, Arizona – Dozens of Rufous and Calliope Hummingbirds fill this canyon on their journey south along mountain corridors.
- Mount Resplendent, Veracruz – Up to 1,400 hummingbirds per hour have been recorded at this 9,000 foot peak in eastern Mexico.
These remarkable gatherings result from hummingbirds being funneled along migration routes to prime habitat where food abounds. The concentrations allow researchers to band and study hummingbirds in large numbers to better understand their migrations.
Threats and Research Needs
While hummingbird migrations have likely occurred for thousands of years, some worrying trends have emerged that threaten their continued success:
Habitat Loss
Development, logging, and agriculture diminishes forests and gardens needed by migrating hummingbirds for food and rest. If stopover sites are degraded or disappear, the stamina of these tiny travelers becomes compromised.
Climate Change
Flower blooms and insect hatches are happening earlier across many regions due to warming temperatures. This may create a mismatch where hummingbirds arrive after the peak availability of food during migration. How hummingbird migration timing will adapt to accelerated changes in seasonal conditions is unknown.
Light Pollution
Evidence indicates bright urban lights can disorient migrating hummingbirds traveling at night, diverting them off-course and exhausting their limited energy stores. More research is needed to understand this phenomenon and how to reduce impacts through public policy and education.
Key areas where more scientific study could help safeguard hummingbird migrations include:
- Gathering more banding data to better map migration routes and monitor populations
- Understanding genetics of migration and orientation abilities
- Tracking individual birds with transmitters to follow complete journeys
- Researching how warming climates affect migration timing and stopover habitat
- Studying influence of urbanization and light pollution on migratory success
The long journeys made by hummingbirds between North America and Central America rank as one of the most incredible migratory feats on Earth. Better understanding of their migration ecology through increased study will help ensure these aerial jewel of nature continue dazzling new generations.
Conclusion
The tiny hummingbird’s giant migration serves as an inspiring reminder of nature’s surprising resilience. In their annual odyssey spanning thousands of miles, hummingbirds display remarkable endurance and navigational ability despite their diminutive size. While threats exist from human impacts like habitat loss and climate change, increased scientific knowledge and conservation action focused on protecting critical stopover habitats can ensure these beautiful migrants continue undertaking one of the most phenomenal migrations on the planet. The long voyage of the hummingbirds – if properly safeguarded by environmental policies and education – will continue linking the nations of North America in a shared natural wonder. Their spectacular passage each year between generations symbolizes the lasting connections woven across borders when we properly value our shared ecological heritage.
