Quick Answer
Allen’s hummingbirds are year-round residents along the Pacific Coast from southern Oregon to Baja California. They do not make long migrations like some other hummingbird species. However, they do make small local movements based on the availability of food and other resources.
Allen’s hummingbirds (Selasphorus sasin) are small, colorful birds named after Charles Andrew Allen, who collected the first specimen in 1852. They are common along the Pacific Coast from southern Oregon to Baja California.
Identification
Male Allen’s hummingbirds have striking plumage with iridescent orange throats and coppery green backs. Females and juveniles are less colorful with green backs and white undersides with green flecks on the throat. Allen’s hummingbirds have a straight, thin bill and tail feathers with white tips. They measure 3 to 3.5 inches in length and weigh 2-3 grams.
Habitat
Allen’s hummingbirds are found in a variety of habitats including coastal scrub, chaparral, woodland edges, parks, and gardens. They occur at elevations up to around 5,000 feet. They are common in urban and suburban areas where flowering plants provide nectar.
Range
The breeding range of Allen’s hummingbirds extends along the Pacific Coast from southern Oregon to southern California. Their year-round range covers coastal California from Marin County south to Baja California. Some birds may wander east into Nevada, Utah, and Arizona.
Do Allen’s Hummingbirds Migrate?
Unlike some species that make long migrations, Allen’s hummingbirds are resident throughout their range and do not make major migrations. However, they do make small local movements and seasonal shifts following flower blooms and other food sources.
Winter Movements
In winter, many Allen’s hummingbirds move towards the coast and lower elevations. This is likely driven by the availability of flowering plants, warmer temperatures, and more moderate conditions near the ocean. They often gather in areas with winter-blooming plants and feeders provided by homeowners.
Altitude Shifts
Breeding birds are found at higher elevations in summer. After nesting, Allen’s hummingbirds move to lower coastal areas and canyons for the winter. This seasonal shift in elevation allows them to take advantage of different flower and food resources through the seasons.
Irruptions
In some years, more significant numbers of Allen’s hummingbirds move outside their typical range. For example, irregular winter influxes are recorded in Arizona and New Mexico. These irruptions may be driven by limited food or harsh weather conditions.
Do Females and Males Migrate Differently?
There are no major differences between male and female Allen’s hummingbirds in their migratory habits. Both sexes make similar local movements depending on food availability, weather, and other factors.
However, adult males tend to arrive at breeding areas a few weeks before females in late winter and spring. This allows them to establish breeding territories early.
Overwintering Differences
Within the wintering range, there are some differences in habitat use between males and females:
- Males prefer open coasts, coastal scrub, and chaparral.
- Females are more likely found in residential areas and at feeders.
This may reduce competition for food resources. But there is no evidence males and females migrate different distances.
What Triggers Migratory Movements?
Allen’s hummingbirds do not make true long-distance migrations. But their local movements seem to be influenced by:
Food Availability
Access to nectar-producing flowers is a major driver of movements. Allen’s hummingbirds go where flowers are blooming through the seasons.
Weather Conditions
Freezing temperatures and snow may prompt southward or coastal movements. Mild coastal areas provide refuge from harsh inland weather.
Breeding
Birds move to higher elevation breeding areas in spring and summer, following flower blooms. After nesting, they descend to lower elevations for winter.
Interspecies Competition
Competition with other hummingbird species may influence local movements.
How Far Do They Migrate?
Allen’s hummingbirds do not make true long-distance migrations of thousands of miles like some species. Their movements are typically over much shorter distances:
- Seasonal elevation shifts of a few dozen to a few hundred miles between breeding and wintering areas.
- Coastal movements up to a few hundred miles between inland and coastal areas.
- Irregular winter dispersals outside the normal range may reach 500 miles or more.
So while Allen’s hummingbirds move in response to seasonal conditions, their migrations only cover relatively short distances compared to long-haul migrants.
What is Their Migration Route?
Allen’s hummingbirds do not have a single fixed migration route like some species. Their movements are more flexible and influenced by local conditions. But some patterns are typical:
Southward Coastal Movement
Many birds move south and towards the coast for winter, some crossing the Transverse Ranges to reach coastal southern California.
Downslope Movement
Breeding birds in mountain ranges like the Cascades and Sierras descend to nearby lowlands and canyons in winter.
Irruptive Wandering
In some winters, vagrant birds turn up hundreds of miles inland such as in Arizona, driven by weather or food shortages.
| Season | Typical Movement |
|---|---|
| Spring | To higher elevations and inland for breeding |
| Summer | At higher elevation breeding areas |
| Fall | To lower elevations and coasts for winter |
| Winter | At lower elevations, often along the coast |
When Does Migration Occur?
The timing of local movements by Allen’s hummingbirds depends on the type of movement:
To Breeding Areas
They start moving inland and to higher elevations in February and March. Adult males arrive first to establish territories.
Downslope/Coastal for Winter
This movement happens in late summer and fall, from July through November, peaking in August-September.
Irruptive Wandering
Unusual winter dispersals occur December through February during the core winter months.
| Movement Type | Typical Timing |
|---|---|
| To breeding areas | February – March |
| Downslope/coastal for winter | July – November |
| Irruptive wandering | December – February |
So while not true long-distance migrants, Allen’s hummingbirds do show seasonal movement patterns.
How Long Does Migration Last?
The duration of Allen’s hummingbird migration and movements depends on the type:
Breeding Area Movement
Males arrive at higher elevation breeding sites over a period of 4-6 weeks beginning in late February. Females arrive 2-3 weeks after males.
Wintering Area Movement
The downslope movement to wintering areas is more prolonged, occurring over 4-5 months from July through November.
Irruptions
Unusual winter dispersals occur over a 1-3 month period, not a steady migration. Birds may remain in atypical areas for several months.
So while not a distinct migration period, Allen’s hummingbirds show extended seasonal movement patterns over several months.
Conclusion
In summary, Allen’s hummingbirds are year-round residents along the west coast of North America. They do not make long-distance migrations but do exhibit some important seasonal movements:
- Altitudinal migration between higher breeding areas and lower wintering elevations
- Local migration between inland and coastal areas
- Irregular winter dispersals well outside the normal range in some years
These movements are driven by flower/food availability, weather, breeding behavior, and competition. So while they do migrate, Allen’s hummingbirds migrate much shorter distances compared to species that undertake transcontinental journeys. Their migrations are better described as seasonal movements across their resident range.
