Hummingbirds are found naturally only in the Americas, from Alaska to Chile, with the greatest variety being in South America. Their habitats include a wide range of conditions from rainforests to deserts and mountains to grasslands. Hummingbirds have adapted to take advantage of flower nectar as their primary food source and thus are found in areas that support flowering plants.
Tropical rainforests
Many hummingbird species are found in tropical rainforests. These forests typically receive over 80 inches of rainfall per year and have consistent warm temperatures year-round. The combination of warmth and rainfall allows for an abundance of flowering plants, providing copious nectar for hummingbirds. Rainforests support around 25-30 hummingbird species, including gemsboks, hermits, mangoes, coquettes, mountain gems, sylphs, and jacamars.
Within the rainforest habitat, different hummingbird species occupy their own niches based on factors like size, bill shape, territorial behavior, and preferred plants. For example, hermit hummingbirds have long decurved bills that allow them to feed on flowers with long corollas that cannot be accessed by shorter-billed species. Territorial hummingbirds like Jacobins defend flower patches from other hummingbirds and insects.
Key features of rainforests for hummingbirds:
- Consistent warmth and high rainfall
- High plant biodiversity, especially flowering plants
- Stratified structure with canopy, understory, and floor levels
- Abundant insects for food
- Sufficient protected perches and nest sites
The rich nectar supply allows tropical rainforests to support very high densities of hummingbirds, in some cases over 100 individuals per hectare. However, habitat loss and fragmentation in these delicate ecosystems threaten many specialized hummingbird species.
Cloud forests
Cloud forests, also called montane forests, are found in mountainous tropical areas. They are wet, cool, and misty forests that receive moisture from clouds and fog in addition to rainfall. The elevation and cloud cover of cloud forests create ideal conditions for many specialized flowering plants, bromeliads, and orchids.
Cloud forests support a variety of hummingbird species including hillstars, sylphs, pufflegs, thorntails, emeralds, and mountain-gems. The cooler temperatures and thinner air of cloud forest habitats have led to unique adaptations in hummingbirds found there, including dense plumage, higher oxygen affinity in the blood, and long wingspans.
Key features of cloud forests for hummingbirds:
- High elevation mountains
- Heavy mist and fog
- Rich sources of nectar from epiphytes and flowers
- Extensive moss covering trees and soil
Cloud forests represent an extremely delicate ecosystem under substantial threat from climate change and habitat destruction. The disruption of cloud forests threatens numerous specialized and endangered hummingbird species that occur nowhere else on Earth.
Dry forests and scrublands
Dry forests and tropical scrublands receive far less rainfall than tropical rainforests, with distinct wet and dry seasons. Though dry overall, these habitats can explode with flowers after a period of rain. Adapted hummingbird species take advantage of this seasonality by timing their breeding and migration to coincide with peak flower availability.
Dry forest hummingbirds include sheartails, woodstars, emeralds, and caribs. They have adaptations for desert-like conditions including tolerance of high temperatures, water efficient kidneys, and the ability to enter torpor to conserve energy and water overnight.
Key features of dry forests and scrublands:
- Distinct wet and dry seasons
- Less than 80 inches of annual rainfall
- Cacti and deciduous trees and shrubs
- Very high temperatures
The brief flowering seasons of dry forests selective for hummingbirds that can take advantage of narrow time windows. Climate change threatens to disrupt these delicate seasonal balances.
Temperate forests
Temperate forests characterized by deciduous trees are found in Eastern North America, Europe, Eastern Asia, Chile, and parts of Australia and New Zealand. Only one hummingbird species, the ruby-throated hummingbird, is native to temperate North America. Others like the Anna’s hummingbird and rufous hummingbird migrate there for the summer from tropical regions.
The ruby-throated hummingbird times its migration precisely with the flowering of plants. It feeds on the nectar of flowers like columbines, bee balms, and trumpet vines. A key adaptation is the ability to enter torpor at night when flowers close and food is not available.
Key features of temperate forests:
- Distinct seasons – warm summers and cold winters
- Deciduous trees like maples, oaks, and beeches
- Lower overall diversity than tropical habitats
- Nectar-producing flowers like lilies, sage, and columbines
Only a few hummingbird species can handle the cold winters and seasonal nature of resources in temperate forests. Migratory hummingbirds retreat south each fall as the nights grow longer and colder.
Alpine meadows
Alpine meadows occur at high mountain elevations above tree line. The lower air density, intense UV radiation, freezing temperatures, and battering winds of alpine zones create an extremely challenging environment. Several hummingbird species inhabit alpine meadows in the Andes mountains including hillstars, giant hummingbirds, and Sylphs.
Alpine hummingbirds have unique adaptations like dense insulating plumage, enlarged hearts and lungs, hemoglobin with a high oxygen affinity, and the ability to torpor to survive at high elevations and cold temperatures. They get most of their energy from flower nectar and feed on small insects for protein.
Key features of alpine meadows:
- High elevations above tree line
- Low temperatures including freezing
- Scarce vegetation and low insect populations
- Intense UV radiation
- Low oxygen availability
Only a handful of specialized hummingbird species can survive the intense conditions found in alpine areas. They represent some of the most extreme adaptations found among hummingbirds.
Deserts and scrublands
Hot deserts with little rainfall present a difficult environment for hummingbirds. Nevertheless, a few specialized species inhabit arid habitats including Coasta’s hummingbird, Lucifer hummingbird, and Berylline hummingbird. They are found in areas like the Sonoran and Chihuahuan Deserts where flowering cacti and agaves provide vital nectar.
Desert hummingbirds exhibit excellent heat tolerance and can dissipate excess body heat through their respiratory system. To conserve water, they have very concentrated urine and specialized kidneys to reduce fluid loss.
Key features of deserts:
- Low annual rainfall – less than 10 inches
- High temperatures exceeding 100°F
- Sparse shrub and cacti vegetation
- Specialized flowers adapted to arid conditions
The hot, dry conditions of deserts make them inhospitable to most hummingbird species. Only a handful of specialists survive by taking advantage of scattered oases and flowering plants.
Grasslands
Grassland habitats are characterized by a lack of trees, dominated primarily by grasses and low shrubs. In South America, the vast savanna-like grasslands known as the pampas provide habitat for dozens of hummingbird species. North American grasslands support migrant hummingbirds during the breeding seasons including rufous hummingbirds and calliope hummingbirds.
Grassland hummingbirds are adapted to fly long distances between scattered food plants. They build nests low in shrubs or even right on the ground. Grassland species include mountain-gems, woodstars, hillstars, sylphs, emeralds, and mangoes.
Key features of grasslands:
- Dominated by grasses and herbaceous plants
- Few trees or large shrubs
- Low precipitation
- Flowering herbaceous plants
- Seeds and insects for food
Hummingbirds frequent grasslands during the peak flowering seasons. Grassland degradation and the spread of agriculture threaten the habitat of many specialized hummingbird species.
Coastal scrub
Coastal scrub consists of low shrubs, grasses, and herbs in Mediterranean climates along coastlines. Species like Allen’s hummingbird and rufous hummingbird inhabit coastal California scrub where they feed on flowers like bush monkeyflower, coastal paintbrush, and currants.
Coastal scrub plants have adapted to dry summers and wet winters. Hummingbirds rely on nectar from blooms during the winter and spring when moisture is sufficient to support plant growth.
Key features of coastal scrub:
- Mediterranean climate with wet winters, dry summers
- Low growing woody shrubs and succulents
- Drought tolerant plants
- Coastal influence – moderate temperatures, wind, fog
The plants and hummingbirds of coastal scrubs are threatened by habitat degradation from human disturbance, grazing, and expanding urbanization along coastlines.
Suburban gardens and parks
Increasingly, hummingbirds are taking up residence in suburbia. Backyard hummingbird gardens and neighborhood parks provide vital habitat as native habitats are lost to development. Species like the Anna’s hummingbird and ruby-throated hummingbird readily inhabit gardens and parks where there are sufficient flowers and feeders.
Landscaping with hummingbird favorites like fuchsias, coral honeysuckle, bee balm, and trumpet vines can transform suburban yards into hummingbird habitat. Maintaining mature trees provides protected nesting sites.
Key features of suburban green spaces:
- Ornamental flowers and shrubs
- Native plants alongside exotics
- Irrigation and landscaping
- Trees for perches and nest sites
- Supplemental feeding stations
Suburban neighborhoods and parks provide vital sanctuary for hummingbirds displaced by development and habitat loss elsewhere. Thoughtful gardening and landscaping can promote hummingbird diversity.
Conclusion
Hummingbirds inhabit an impressive range of habitats across the Americas. From lowland rainforests to mountaintop meadows, hummingbirds have adapted to take advantage of flower nectar in diverse ecosystems. Key features that make a habitat suitable for hummingbirds include:
- Abundant nectar-producing flowers
- Insects for protein
- Protected perches for resting and night roosting
- Nest sites – trees, shrubs, rock overhangs etc.
- Sufficient precipitation to support flowers and vegetation
- Moderate temperatures with sufficient warmth for breeding
As specialized nectar feeders, hummingbirds serve as important pollinators in nearly every habitat where they occur. Unfortunately, many hummingbird habitats are under threat from development, climate change, logging, grazing, and other human disruptions. Supporting native plant communities and providing supplemental food and nesting sites can help hummingbird populations persist even in human-altered environments.
