Hummingbirds are found naturally only in the Americas. They range from southeastern Alaska to southern Chile, occupying diverse habitats from sea level to over 16,000 feet in elevation. There are over 300 described species of hummingbirds, making them the second most diverse family of birds after flycatchers. Their small size, colorful plumage, and remarkable flying abilities have made hummingbirds one of the most popular and charismatic groups of birds. In this article, we will explore the extensive geographic range of hummingbirds and what factors allow them to thrive across such a broad area.
Hummingbirds of North America
Seventeen species of hummingbirds are regularly found in the United States and Canada. The northernmost is the Ruby-throated Hummingbird, which breeds across eastern North America and winters as far south as Panama. In the western U.S., species like the Rufous and Anna’s Hummingbird breed during the summer and migrate south to Mexico for the winter. Other species such as the Costa’s Hummingbird have more restricted breeding ranges in the desert southwest.
Many hummingbird species occupy only a small portion of North America and are regional endemics. For example, the Lucifer Hummingbird lives solely in a small area of northern Mexico. The Berylline Hummingbird breeds only in the oak woodlands of southeast Arizona, southwest New Mexico and northern Mexico. Isolated mountain ranges are havens for unique hummingbirds like the Blue-throated Hummingbird found only in the Chisos Mountains of Texas.
Several factors influence hummingbird distribution in North America, including:
- Flower availability – Hummingbirds feed mainly on nectar, so their movements track blooming cycles of favored plants.
- Development of traplining behavior – Many hummingbirds return repeatedly to feed at the same patches of flowers, enabling efficient foraging.
- Competition with other hummingbird species – Aggressive species like Anna’s Hummingbird tend to dominate and exclude other types from their prime habitat.
- Adaptation to regional climate conditions – For example, fat-storing capability allows Rufous Hummingbirds to survive cold winters.
Notable Geographic Areas for Hummingbirds in North America
Southeastern Arizona – Up to a dozen species breed here, the greatest diversity anywhere in the U.S. Elevational migration allows species turnover between mountain ranges.
Southwest U.S. and Northern Mexico – Many range-restricted species occur only in this arid region including Berylline, Lucifer, and Violet-crowned Hummingbirds.
Florida – The aptly named Mangrove Hummingbird is found only along the southwestern coast, while the endemic Cuban Emerald inhabits the Florida Keys.
Pacific Coast – Anna’s and Costa’s Hummingbirds thrive in urban areas and occupy a wide coastal strip. Rufous Hummingbirds migrate through this region in huge numbers.
Hummingbirds of Central America
Central America serves as a transition zone between the Nearctic and Neotropical realms. More than 40 species of hummingbirds can be found here, including both North American migrants and South American vagrants. Resident species like the Purple-crowned Fairy have evolved to take advantage of specialized habitats like rainforests and cloudforests.
Some areas of high hummingbird diversity in Central America include:
Talamanca Mountains – Over 35 species recorded in this rugged region including rare endemics like the Coppery-headed Emerald.
Mosquitia Region – Extensive lowland rainforests host widespread species alongside those with tiny ranges like the Little Hermit.
Western Panama – Hummingbirds concentrate along this narrow land bridge which connects North and South America.
As a slender land bridge between two continents, Central America provides a crucial dispersal route for hummingbirds. But periodic land barriers over time have also driven speciation as populations get isolated. The result is a dynamic mix of species with origins in both North and South America.
Key Factors Influencing Central American Distributions
- Varied topology and rainfall patterns which provide diverse habitat zones.
- Position along major migration routes for North American species.
- Gateway for colonization by South American taxa.
- Development of endemic forms restricted to regional habitats.
Hummingbirds of South America
South America has the highest diversity of hummingbirds anywhere, with over 140 described species. The Andes Mountains contain the most species, especially at mid-elevations from around 1,500-3,000 m. However, hummingbirds occupy a remarkable array of habitats across the continent, from paramo grasslands to tropical rainforests to Patagonian scrub.
Here are some key biogeographic patterns among South American hummingbirds:
Andean Endemics – Many species are restricted to specific ridges or valleys in the Andes, like the Ecuadorian Hillstar of western Ecuador.
Tepui Specialists – A number of taxa inhabit the isolated table mountains (tepui) of Guiana, including the Tufted Coquette.
South American Migrants – Most migratory hummingbirds that breed in North America, like the Ruby-throated, winter in South America.
Widespread Lowland Species – Some taxa like the Glittering-bellied Emerald occupy a broad range across multiple countries and habitat types.
Rare Island Forms – Unique species are found on offshore islands like Trinidad and Tobago as well as the Juan Fernández Islands off Chile.
Major Habitat Zones for Hummingbirds in South America
| Habitat | Description | Example Species |
| Andean Cloudforest | Moist, cool forests at high elevations | Glowing Puffleg |
| Amazon Basin | Extensive tropical lowland rainforest | Black-eared Fairy |
| Caatinga | Arid scrublands of eastern Brazil | Plovercrest |
| Southern Cone | Temperate grasslands and scrub | Oasis Hummingbird |
How Hummingbirds Colonized such a Vast Range
Multiple factors have allowed hummingbirds to expand across the Americas from their origin in South America:
Small body size – By evolving as one of the smallest birds, hummingbirds are highly mobile and require minimal resources.
Specialized nectar diet – Hummingbirds can feed on any flowers providing adequate nectar, widely available across habitats.
High metabolism – They have among the highest metabolic rates of any animals, fueling their constant activity.
Agility in flight – Maneuverable flight gives hummingbirds access to food sources unavailable to other birds.
Adaptations to altitude – Hemoglobin modifications allow some species to thrive at extremes of high elevation.
Behavioral flexibility – Traplining, latitude shifts, and elevation migration all help hummingbirds exploit seasonal resources.
Challenges to Dispersal
However, some barriers have historically limited their distribution:
- The Andes – This formidable mountain chain has isolated populations and driven speciation.
- Ocean barriers – Hummingbirds are weak fliers over open water, limiting overwater colonization events.
- Climate extremes – Very cold temperatures restrict their range from expanding farther north.
- Ecological competition – Aggressive species often outcompete and exclude other hummingbirds from optimal habitat.
Conclusion
In summary, hummingbirds occur naturally across a remarkable diversity of habitats in the Americas, from southeast Alaska to the Straits of Magellan. Their small size, dietary flexibility, and unique adaptations have allowed them to exploit resources across this vast range. However, dispersal barriers like mountain chains and open water have historically limited their distributions in places. Close to 350 species have been described, exhibiting an astonishing array of evolutionary specializations. The geographic movements of these charismatic birds will continue to reveal insights into ecology and biogeography across the Americas. Their expansive range is a testament to the tenacity and flexibility of hummingbirds.
