No, hummingbirds do not stay in Colorado all year. Hummingbirds are migratory birds that spend the summer in Colorado to take advantage of the abundance of flowers and food available. As winter approaches and temperatures drop, hummingbirds migrate south to warmer climates.
When do hummingbirds arrive in Colorado?
Hummingbirds usually start arriving in Colorado in early May. The broad-tailed hummingbird is one of the first to arrive, followed by the calliope hummingbird in late May. By early June, most of the summer residents like rufous and black-chinned hummingbirds have returned to Colorado.
The timing of hummingbird migration is determined by the blooming of flowers that provide nectar. Hummingbirds time their migration to arrive when favorite flowers like columbines, honeysuckles, and trumpet vines start blooming. Warm temperatures also ensure there are plenty of insects for the birds to eat.
What types of hummingbirds live in Colorado in summer?
There are 6 species of hummingbirds commonly found in Colorado during summer:
Broad-tailed Hummingbird
The broad-tailed hummingbird is the most common hummingbird in Colorado. It breeds throughout the state in mountain meadows and foothill canyons. The male has a metallic green back and bright pink throat feathers.
Rufous Hummingbird
The rufous hummingbird nests in forests and mountain meadows in western Colorado. The male has distinctive orange-red throat feathers.
Calliope Hummingbird
The tiny calliope hummingbird breeds at high elevations like mountain meadows and pine forests. The male has colorful purple-red throat feathers.
Black-chinned Hummingbird
The black-chinned hummingbird nests along rivers and streams, preferring scrubby riparian habitats. The male has a dark purple throat with a thin black chin strap.
Broad-billed Hummingbird
Uncommon in Colorado, but breeds in small numbers in the southwestern part of the state. It has a very short bill and a bright green back.
Anna’s Hummingbird
Very rare in summer but increasing reports in Colorado as it expands its range northwards. The male has striking rose-pink throat feathers.
What do hummingbirds eat in Colorado?
Hummingbirds get most of their nutrition from drinking nectar from colorful tubular flowers like columbines, trumpet vines, penstemons, and honeysuckles. They use their long, specialized beaks and tongues to reach deep into the flowers for the nectar.
Hummingbirds also consume large amounts of small insects and spiders to get essential amino acids and fat that they cannot get from nectar. They hunt insects in flight or pick them off leaves and branches. Common prey includes mosquitoes, fruit flies, gnats, beetles, caterpillars, spiders, and aphids.
At feeders, hummingbirds will drink sugar-water mixtures designed to replicate the ratio of sugars found in natural nectars. They can get 25% of their daily calories from feeders in Colorado.
Do hummingbirds mate and nest in Colorado?
Yes, Colorado provides ideal breeding habitat for hummingbirds in summer. The females build tiny, cup-shaped nests out of soft plant down, spider webs, lichens, and moss. The golf ball-sized nests are often camouflaged on horizontal branches in trees and shrubs.
Females lay 2 pea-sized white eggs in the nests and incubate them for 2-3 weeks. The hatchlings are fed regurgitated nectar and insects by the female. They fledge in about 3 weeks, soon after their first flight feathers grow in.
Here is a table showing the nesting details for common hummingbird species found in Colorado:
| Species | Nesting Habitat | Clutch Size | Incubation Period |
|---|---|---|---|
| Broad-tailed | Mountain meadows, canyons | 2 eggs | 16 days |
| Rufous | Forests, mountain meadows | 2 eggs | 16 days |
| Calliope | High elevation meadows, pine forests | 2 eggs | 15-18 days |
| Black-chinned | Riparian areas, scrublands | 2 eggs | 16 days |
When do hummingbirds migrate south from Colorado?
Most hummingbirds leave Colorado by the end of September or early October. The timing depends on the species and the approaching cold temperatures.
Rufous hummingbirds are usually the first to depart, leaving in July and August. Calliope and broad-tailed hummingbirds follow by early September. Black-chinned hummingbirds depart in mid-September.
By late September, only a few stray individuals remain in the state. Rare sightings can continue into October. But food becomes scarce as flowers die off with freezing temperatures and snow. This lack of food forces the last stragglers to migrate south.
Where do hummingbirds that summer in Colorado migrate for winter?
The hummingbirds that breed in Colorado migrate south to Mexico and Central America to spend the winter.
Here are the winter ranges for common Colorado hummingbirds:
Broad-tailed:
Mexico, south to Guatemala
Rufous:
Mexico along the Pacific Coast
Calliope:
Mexico south to Nicaragua
Black-chinned:
Mexico along the Gulf Coast and Southern Baja
The long journey south provides a constant supply of flower nectar and insect food. The tropical environments do not experience freezing temperatures and snow cover like Colorado winters.
Do any hummingbirds stay year-round in Colorado?
No, there are no hummingbirds that remain in Colorado throughout the winter. Even unusual sightings in winter are likely just birds passing through during migration rather than overwintering.
The extreme cold weather and snow make winter survival impossible for hummingbirds in Colorado. Frigid temperatures lead to torpor and death without adequate food supplies from flowers and insects. Access to unfrozen liquid water is also a challenge.
Hummingbirds have adapted to migrate long distances to warmer climates for winter survival. While other bird species like chickadees and juncos can survive the winter in Colorado, hummingbirds cannot. They must seek out tropical environments further south.
Can hummingbirds survive Colorado winters?
No, hummingbirds cannot survive harsh Colorado winters on their own. Below freezing temperatures and scarce food supplies make overwintering extremely difficult.
Hummingbirds are vulnerable to cold weather because of their small body size and high metabolism. They can enter torpor by lowering their body temperature and heart rate. But torpor is not sustainable for more than a few hours in freezing temperatures.
Without adequate calories from flower nectar and insects, hummingbirds will quickly deplete their fat reserves. They can die from starvation, exposure, or freezing nighttime temperatures.
The lack of flowers and nectar due to snow cover is another threat. And any remaining insects or spiders are dormant and unavailable as food. Access to liquid water is also limited by freezing.
These extreme winter conditions exceed the survival adaptations of hummingbirds. That is why migration is the only strategy that enables them to persist and breed in Colorado in summer.
Conclusion
In conclusion, hummingbirds depend on migration to survive the winters in Colorado. They begin arriving in May to take advantage of the peak nectar and insect food supplies in summer. Rufous hummingbirds start departing in July, followed by other species in August and September. By late September, only a few stragglers remain.
Hummingbirds migrate south to Mexico and Central America where they can find tropical environments with flowers, insects, and unfrozen water. Attempting to overwinter in Colorado would lead to starvation, exposure, or freezing due to the harsh conditions. That is why no hummingbirds stay year-round, instead relying on migration to return to Colorado each spring.
