Hummingbirds are remarkable little birds that capture the imagination with their diminutive size, iridescent plumage, and amazing flying skills. These tiny birds seem delicate, yet they are incredibly resilient, with some species migrating thousands of miles every year between their summer and winter homes.
New England is home to several species of hummingbirds during the spring and summer months. However, as autumn approaches and temperatures begin to drop, most hummingbirds that spent the breeding season in New England migrate south to warmer climates. Their winter destination depends on the species.
Ruby-throated Hummingbird
The Ruby-throated Hummingbird is the most common and widespread hummingbird species found in New England during summer. As winter nears, Ruby-throats embark on a strenuous journey across the Gulf of Mexico to their wintering grounds in Central America.
Most Ruby-throated Hummingbirds winter between southern Mexico and Panama. Southern Mexico, including the Yucatan Peninsula and other parts of the country’s eastern coast, harbors large numbers of wintering Ruby-throats. Central American countries such as Guatemala, Belize, El Salvador, Honduras, Nicaragua, and Costa Rica also provide key overwintering habitat.
Amazingly, Ruby-throats make this migration across 500-600 miles of open water in a single flight. They gain enough body fat to fuel this arduous journey, doubling their weight before departure. Their migration typically takes 18-24 hours depending on weather conditions.
Rufous Hummingbird
The Rufous Hummingbird is a common summer resident and breeder in northern New England. This species winters along the Gulf Coast of the United States and Mexico after a remarkable migration.
Most Rufous Hummingbirds that breed in New England migrate down the interior of North America to reach their Gulf Coast wintering grounds. They stop to rest and refuel in flower gardens, backyards, and other habitats rich in nectar-producing flowers along their migration route.
Popular wintering destinations for Rufous Hummingbirds include Louisiana, southern Texas, southern Alabama, and the Florida panhandle. Northern and central Mexico are also important wintering areas for this species.
Calliope Hummingbird
The tiny Calliope Hummingbird is the smallest breeding bird in New England. It breeds at higher elevations but migrates through many parts of the region in spring and fall.
After leaving their breeding grounds across Canada and the northern United States, Calliope Hummingbirds migrate south along the Pacific Coast to winter primarily in Mexico. They are uncommon along the Gulf Coast and do not normally travel as far south or east as Ruby-throats and Rufous Hummingbirds.
Calliopes take a coastal route to wintering grounds that are mainly concentrated along Mexico’s central and southern Pacific Coast. The states of Sinaloa, Jalisco, Guerrero and Oaxaca host significant wintering populations of Calliope Hummingbirds.
Broad-tailed Hummingbird
The Broad-tailed Hummingbird does not breed in New England but passes through during migration. This species winters in central Mexico after breeding across the western United States and the Rocky Mountains.
From its breeding range, the Broad-tailed Hummingbird migrates south through the Great Basin and interior Southwest. The birds arrive in high-elevation mountain areas in Mexico’s Sierra Madre Occidental range by early winter.
The northern and central Mexican states of Sonora, Chihuahua, Durango, Zacatecas, and Jalisco provide critical overwintering habitat for Broad-tailed Hummingbirds.
Arrival on the wintering grounds
Most hummingbirds leave New England by early October, but timing depends on the species, weather, and availability of food. Ruby-throated Hummingbirds are typically the first to depart, usually by late September. Rufous Hummingbirds follow shortly after.
Arrival on the wintering grounds also varies. Ruby-throats show up in southern Mexico and Central America as early as July but most arrive in September and October. Rufous Hummingbirds generally start reaching the Gulf Coast in August with peak numbers in September.
Banding and tracking studies show Calliope and Broad-tailed Hummingbirds typically arrive on their Mexican wintering grounds in September and October. However, some individuals linger as far north as possible until cold weather forces them to migrate.
Climate of wintering regions
Hummingbirds winter in relatively warm, temperate climates, often with distinct wet and dry seasons. Central America, coastal Mexico, and the U.S. Gulf Coast provide generally mild winters without extremely cold temperatures.
Here are typical winter temperature ranges in some key hummingbird wintering zones:
| Wintering Region | Average Low | Average High |
|---|---|---|
| Southern Texas | 45°F / 7°C | 68°F / 20°C |
| South Florida | 60°F / 15°C | 75°F / 24°C |
| Pacific Coast, Mexico | 50°F / 10°C | 82°F / 27°C |
| Yucatan Peninsula | 65°F / 18°C | 89°F / 31°C |
| Central Costa Rica | 65°F / 18°C | 82°F / 28°C |
These tropical and subtropical climates provide the warmth, food sources, and habitat hummingbirds need to survive the winter until they can migrate north again.
Habitat and food sources
Three key habitat types hummingbirds rely on during winter are tropical forests, subtropical scrublands, and residential gardens and parks. These habitats supply the blooming flowers, flowering trees, nectar feeders, and insects the birds need.
Tropical forests
Hummingbirds often inhabit the edges of tropical lowland and mountain forests in locations like southeastern Mexico, Central America, and the Caribbean. These forests bloom year-round, providing continuous floral nectar and insect food sources.
Common nectar sources include wildflowers like honeysuckle and amaranth as well as native trees and shrubs such as citrus, coralbean, and pineapple sage. Insects like mosquitoes, gnats, beetles, and spiders supplement the diet.
Subtropical scrublands
Hummingbirds overwintering along the Gulf Coast rely on the diverse nectar plants and blooming trees found in subtropical scrublands. These habitats with scattered trees, shrubs, and cacti cover many interior and coastal areas.
Salvias, African daisies, honeysuckles, coral honeysuckle, and desert willow are some scrubland plants that provide important food sources. Insects round out the diet.
Backyards and gardens
In both native habitats and developed areas, hummingbirds seek out backyard feeders and ornamental flowers for easy meals. Nectar feeders provide up to a third of daily energy needs during winter.
Non-native, nectar-rich plants like lantana, bougainvillea, hibiscus, aloe, and impatiens are common in gardens, parks, and urban areas. They help sustain wintering hummingbirds in combination with arthropod prey.
Behaviors and activities
Hummingbirds exhibit specialized behaviors and activities during the winter centered around conserving energy and staying nourished.
Feeding
Hummingbirds feed frequently by visiting flowers, feeders, and favorable trees and shrubs. They consume more sugars relative to insects in their diet during winter.
Aggressive defense of flower patches and feeders against competing birds is reduced compared to the breeding season. However, some dominant individuals still chase others away from prime food sources.
Resting and torpor
Hummingbirds rest extensively during winter and may enter torpor at night and on cold winter days. Torpor is a deep sleep state that conserves energy. Body temperature and metabolic rate drop substantially.
Torpor bouts allow hummingbirds to survive periods when flower nectar is less available, such as during storms, dry seasons, or cold snaps. However, they may arouse every 24 hours to eat and refuel their depleted energy reserves.
Vocalizations
Chirps, squeaks, and buzzing sounds are used primarily for communication. Aggressive vocalizations are diminished compared to the breeding season, but some chatter and scolding still occurs at feeders.
Soft ticking sounds help hummingbirds stay in contact with flock members. Vocalizations may also play a role in courtship rituals that start in late winter before migration.
Molting
Most adult hummingbirds molt old, worn feathers and grow new plumage on their wintering grounds. This process can take several months. Their bright, iridescent feathers gradually become more vibrant through late winter.
Some juveniles also attain adult plumage during their first winter instead of during the post-breeding molt. The energy-intensive molting period is best supported by the mild winter conditions and plentiful food.
Courtship and mating
Hummingbirds may start courtship displays and mating behaviors by late winter as they prepare to migrate north. These rituals determine future breeding pairs and may begin female ovulation before spring.
Male courtship displays include aerial flying maneuvers and dives to impress females. Some copulation may occur on the wintering grounds before birds depart for their breeding territories.
Dangers and threats
Hummingbirds face a variety of hazards and challenges while wintering in the tropics that may impact their health and survival.
Predators
Predators like hawks, falcons, roadrunners, orioles, flycatchers, and shrikes prey on hummingbirds. Feline predators including domestic cats also take a heavy toll.
Hummingbirds rely on their aerial agility and speed to escape, but cold stress, starvation, or collisions can leave them more vulnerable. Predation risk is lower at residential feeders but still significant.
Extreme weather
Colder temperatures increase energy demands and can be deadly during unusual cold snaps. Hummingbirds may get wet and lose body heat during winter storms.
Drought impacts the availability of natural flower nectar. However, irrigation and feeders at parks and residences help provide alternate food sources.
Habitat loss
Urbanization and agriculture reduce native plant communities hummingbirds rely on for food. However, gardens rich in nectar plants and feeders may help offset habitat losses in some areas.
Pesticides
Chemical contamination from pesticides is an emerging concern. Pesticides applied to crops or gardens can be transferred to hummingbirds through nectar and reduce insect prey.
Conservation and supplemental feeding
Supporting wintering hummingbird populations requires conserving native habitats as well as gardens, parks, and residential feeding.
Habitat conservation
Protecting tropical forests, subtropical scrublands, and riparian corridors provides essential natural food supplies. Ecotourism and shade-grown coffee also incentivize habitat conservation.
Banning or restricting pesticide use reduces chemical threats. Monitoring and controlling feral cats helps lower predation pressure.
Supplemental feeding
Providing clean nectar feeders, cultivating nectar-rich ornamentals, and adding diverse plantings to gardens gives hummingbirds more food options and increases overwinter survival.
Strategically placing feeders close to cover, maintaining fresh nectar, and cleaning regularly reduces disease transmission risk. Public education helps promote responsible feeding practices.
Spring migration
As days lengthen in late winter, hummingbirds undergo physiological changes to prepare for migration. Fat reserves increase, and some birds get an early start heading north.
The urge to migrate is stronger in young birds with no breeding ties. Males generally migrate first followed by females. Most birds wait for optimal conditions and leave between mid-February and early April.
Ruby-throats follow the Gulf coast north before flying inland or crossing the Gulf from Mexico. Rufous Hummingbirds retrace a northbound interior route through the Great Plains and West.
Calliope and Broad-tailed Hummingbirds migrate north through the Southwest and along the West Coast. Timing depends on the destination, but most New England hummingbirds arrive by May or early June to start the breeding cycle again.
Conclusion
New England’s hummingbirds undertake a remarkable journey each year when they migrate hundreds or thousands of miles south to their tropical wintering grounds. Their ability to survive cold winters and find scarce food supplies in a far-off land highlights the resilience and adaptability of hummingbirds.
Understanding migration routes, winter ecology, and conservation needs allows us to better protect these captivating birds and continue enjoying their presence in our gardens. With careful planning, we can help provide the habitat and resources hummingbirds rely on as they spend winter in warmer southern climes.
