Many people wonder if hummingbirds stay in the Portland, Oregon area year-round or if they migrate elsewhere for the winter. Hummingbirds are a popular sight in Portland during the spring and summer months, darting around gardens and feeders. But as winter approaches, the hummingbird activity starts to decline as the birds either migrate south or become less active in the colder weather.
Hummingbird Migration
Most hummingbird species that visit the Pacific Northwest are migratory and do not stay year-round. The most common hummingbird seen in Portland is the Anna’s hummingbird. Anna’s hummingbirds breed in the Pacific Northwest and many birds migrate south in the winter, typically to California and Mexico. However, some Anna’s hummingbirds have adapted to stay year-round in the milder Pacific Northwest climate. This particularly occurs in urban and suburban areas where feeders and non-native flowering plants provide them with a consistent food source.
Other hummingbird species such as rufous hummingbirds and calliope hummingbirds are migratory and do not remain in the Portland area in winter. Rufous hummingbirds breed further north and almost entirely migrate south out of the Pacific Northwest each winter. Calliope hummingbirds have one of the longest migration routes of any bird relative to their tiny body size, breeding in the Pacific Northwest and Canada before migrating all the way to Mexico for the winter.
Migration allows hummingbirds to follow the seasonal abundance of flower nectar and insect food sources. The timing of migration can vary by species, age, weather conditions, food availability and other factors. Some hummingbirds may linger into early winter in the Portland area if food sources remain, before eventually migrating south.
Do Any Hummingbirds Stay in Portland in Winter?
While most hummingbird species migrate south for the winter, a subset of Anna’s hummingbirds has adapted to remain year-round in the Portland area. This is estimated to be around 10-20% of the resident Anna’s hummingbird population. The birds that stay year-round tend to be adult males that have established breeding territories.
Some signs that Anna’s hummingbirds are present in winter include:
- Seeing a hummingbird at a feeder
- Hearing the distinctive metallic chipping call
- Spotting one flying among trees and bushes
Other overwintering hummingbird species such as rufous hummingbirds are only occasionally reported in Portland during the winter months. This is considered unusual but can occur when birds linger later than normal in the fall or arrive earlier in the spring.
How Do Hummingbirds Survive the Winter?
Hummingbirds have adapted some key strategies to survive cold winters in the Pacific Northwest:
- Feeding – Hummingbirds rely heavily on sugar-rich feeders and feeding on any remaining flowers or tree sap.
- Energy conservation – They enter torpor, a short-term hibernation to conserve energy overnight.
- Cold tolerance – They can regulate their high metabolic rate and boost their body temperature on cold nights.
- Shelter – They seek shelter in cavities, thick vegetation and even under roof overhangs.
Backyard feeders become a vital food source, so residents who provide Anna’s hummingbird feeders are helping the overwintering birds survive. The birds build up fat reserves to get through cold nights and periodically enter torpor to conserve energy.
Are Hummingbirds Active in Winter?
Hummingbirds that overwinter in the Portland area are still active during the day, visiting feeders to refuel. However, they are less active than during the breeding season because they enter torpor overnight and periodically during poor weather to conserve energy. The birds are often elusive and quiet during winter.
Some signs of winter activity include:
- A single hummingbird defending a feeder
- Hearing chipping and twittering sounds
- Seeing a hummingbird briefly flying under the eaves or perching during a warm spell
The hummingbirds are still territorial in winter and a single male may defend a feeder. But the birds are not as conspicuous as they are during the summer.
What to Feed Hummingbirds in Winter
Here are some tips for providing food for overwintering hummingbirds in Portland:
- Use a nectar mix ratio of 1 part sugar to 4 parts water. Do not add red food coloring.
- Avoid honey or artificial sweeteners which provide no nutritional value.
- Keep feeders clean, washing them every few days to prevent mold.
- Avoid leaving feeders out overnight when freezing can occur.
- Provide multiple feeders to accommodate territorial behavior.
Feeders should be kept full so hummingbirds have a reliable food source. It’s important not to add red dye since red-colored products are unhealthy for birds. Plain white sugar water has all the nutrition they need.
Other Ways to Help Hummingbirds in Winter
Here are some other tips for supporting overwintering hummingbirds in the Portland area:
- Provide shelter such as non-invasive vines, shrubs, or trees where birds can perch and get cover.
- Supply a shallow bird bath, fountain, or mister for drinking and bathing water.
- Avoid using toxic pesticides which can accumulate in the birds.
- Keep outdoor cats indoors to protect birds.
- Report any sightings or band encounters to researchers.
Consider leaving seed heads and dead plant stems over winter to provide habitat. Also be mindful of window collisions by placing decals on glass or closing blinds/curtains.
Can Hummingbirds Survive Portland Winters?
Overwintering hummingbirds can survive Portland’s cold winters but do face some major challenges:
- Bouts of extended freezing temperatures
- Limited food sources compared to summer
- Lack of insects for protein
- High energy needs to keep warm
Periods of extreme cold below 20°F lasting multiple days make it harder for hummingbirds to balance their energy needs. Some key threats they face are starvation, hypothermia, and predation. Having backyard feeders available is crucial to help supplement their diet.
How Cold is Too Cold for Hummingbirds?
Hummingbirds can withstand surprisingly cold temperatures by lowering their body temperature and slowing their metabolism. However, bitter cold below zero degrees Fahrenheit can be life threatening if exposed for too long without food. Some guidelines on extreme temperatures include:
- Below 20°F – Higher risk of cold stress and starvation
- Below 0°F – Danger of hypothermia and death with prolonged exposure
- Below -20°F – Extreme risk without adequate shelter and food
Providing a reliable food source via feeders helps hummingbirds replenish energy and boost body heat. Cold snaps usually don’t last long in Portland, but an extended period below freezing can jeopardize overwintering birds.
Signs of Cold-Stressed Hummingbirds
Watch for these signs of cold stress in overwintering hummingbirds:
- Lethargy or reduced activity
- Fluffed up feathers
- Shivering
- Lack of appetite
- Huddling under porches or eaves
Take steps to help any cold-stressed hummingbirds such as bringing feeders indoors overnight to prevent freezing, providing shelter, or calling a wildlife rehabilitator for advice. Catching early signs of distress and intervening can help their survival chances.
Interesting Facts About Overwintering Hummingbirds
- Up to 20% of Anna’s hummingbirds that breed in the Portland area may overwinter locally rather than migrate.
- Males appear to be more likely than females to overwinter in the Pacific Northwest.
- Banding programs have recaptured the same birds visiting backyard feeders over multiple winters.
- Hummingbirds can drop their body temperature by 50-60°F overnight to conserve energy.
- Most overwintering hummingbirds in the U.S. are found along the Pacific Coast.
Hummingbird banding programs provide fascinating insights into these tiny birds including their impressive longevity. Observing and supporting the hummingbirds that overwinter in Portland’s urban areas provides a unique opportunity.
Summary
In summary, most hummingbird species that visit Portland in summer migrate south in winter. However, a portion of Anna’s hummingbirds has adapted to remain year-round, comprising an estimated 10-20% of the local breeding population.
These overwintering Anna’s hummingbirds rely heavily on feeders and can survive cold snaps by periodically entering torpor. Backyards with feeders and shelter provide vital resources to help supplement their natural food sources during winter.
While Portland’s winter weather brings challenges, Anna’s hummingbirds are resilient and can successfully overwinter in the area with the help of local residents providing consistent food and habitat. Their year-round presence provides a unique opportunity to observe these tiny birds up close through the changing seasons.
