Hummingbirds are some of the smallest and most fascinating birds found in Washington state. With their iridescent feathers and incredible flying abilities, it’s no wonder they capture the imagination of birdwatchers and nature lovers alike.
But how do these tiny birds, some weighing less than a nickel, survive the harsh Pacific Northwest winters? Especially when many hummingbird species migrate thousands of miles to warmer climates in the fall?
It turns out that hummingbirds have adapted some remarkable strategies to endure the cold winter months in Washington. While most hummingbirds do migrate south, a few hardy species stick around and have evolved specialized behaviors and physiology to survive until spring.
Do any hummingbirds stay in Washington for winter?
Most of the hummingbirds found in Washington state during the summer months migrate south to warmer climates in the fall. However, there are a couple of species tough enough to endure the state’s wet, cold winters.
The Anna’s hummingbird is one species that has adapted to spending the full year in the Pacific Northwest rather than migrating. The Anna’s hummingbird is a medium-sized bird with iridescent emerald and rose plumage. It’s named after a 19th-century duchess, Anna Massena.
Another wintering hummingbird found in Washington is the rufous hummingbird. The rufous is the smallest breeding bird in the Pacific Northwest. The males have bright reddish-orange plumage and perform elaborate courtship dives to attract females.
While most rufous hummingbirds migrate south for winter, some hardy individuals, typically adult males, stick it out in Washington’s milder coastal regions. Scientists estimate there are a few thousand overwintering rufous hummingbirds scattered along the Pacific Northwest coast each year.
How do hummingbirds survive cold winters?
Hummingbirds have evolved some key physiological and behavioral adaptations to survive cold winters in Washington:
Fat reserves
Hummingbirds preparing to overwinter build up their fat reserves during the fall months. They gorge on nectar, tree sap, and insects to store up extra fat so they can survive when food is scarce in winter.
The fat provides insulation against the cold and gives the birds energy when their foraging is limited by bad weather. Anna’s and rufous hummingbirds may nearly double their body weight leading up to winter.
Torpor
To conserve energy on cold nights and during storms, hummingbirds use a hibernation-like state called torpor. Their metabolism slows down dramatically, heart rate drops, and body temperature decreases by up to 50-60°F.
Torpor allows the birds to minimize their energy use on frigid winter nights when they cannot forage. They occasionally wake up to eat from feeders or thawed tree sap before returning to their energy-saving torpor.
Cold hardy feathers
Hummingbirds’ lightweight, compact feathers provide excellent insulation against the cold. Their feathers trap air close to the body to retain heat.
Many cold-weather hummingbirds also grow extra downy feathers for winter insulation. They may get up to 10% larger from this plumage alone. The extra fluff helps keep their tiny bodies warm despite freezing temperatures.
Wind proofs roosts
Hummingbirds find protected places to minimize exposure to cold winds, rain, and snow at night. Favorite roosting spots include thick conifer forests, nestled in the needles of a spruce or fir tree away from the elements.
Cavities in trees or rock crevices also offer shelter. Some hummingbirds wedge themselves into loose bark or lichen for insulation and protection from wind. Finding a good winter roost site can mean the difference between survival and succumbing to exposure.
Sugary foods
In the summer, hummingbirds get most of their nutrition from flower nectar and insects. But winter-blooming flowers are scarce, and bugs hard to come by. Luckily, Anna’s and rufous hummingbirds supplement their diet with tree sap and sugar water from feeders when natural food is limited.
These sugary foods provide quick energy to power the hummingbirds’ wings and keep their metabolism running. Without winter feeders, finding enough food would be challenging in cold weather.
How do hummingbirds survive winter storms?
Washington winters invariably bring storms that could threaten the tiny hummingbirds trying to overwinter in the state. Freezing rains, heavy snowfall, and winter storms with gale-force winds all pose challenges for hummingbirds. Here’s how they survive severe winter weather:
Take shelter
Hummingbirds seek protected shelter out of the wind, cold, and wet conditions during storms. Favored hiding spots include thick bushes and trees, under rocks or eaves, inside garages or crawlspaces, and even on porches if they can sneak indoors!
Their fast metabolism means hummingbirds are at risk of starving if they cannot forage for more than a few hours. Finding cover to wait out storms is critical.
Enter torpor
To reduce their energy needs during harsh storms, hummingbirds rely on their ability to enter torpor. They lower their body temperature and heart rate to near hibernation levels so they burn fewer calories while sheltering from the weather.
This torpor allows them to sleep through the worst of a long-lasting storm without starving. They occasionally wake to grab a quick meal before going back into their dormant state.
Eat before storms
Hummingbirds seem to sense approaching storms. Ornithologists have observed them consuming extra nectar and syrup before bad weather hits to store up more fat reserves.
This extra fuel helps hummingbirds hunker down and wait out even a long storm while expending minimal energy. Their appetite surge is likely an instinctual behavior to prepare for difficult foraging conditions.
Seek heat
While sheltering from the cold, wet conditions, hummingbirds seek any source of heat they can find. They press their tiny bodies against tree trunks warmed by the sun, huddle near dryer vents or other heat sources, or nestle into rock crevices containing trapped geothermal warmth.
Access to heat saves vital calories and reduces their risk of hypothermia during harsh winter storms in Washington. Every bit of warmth matters.
Do hummingbirds migrate through Washington?
While a few hummingbird species tough out Washington’s winters, most migrate south to warmer regions in the fall. The state’s hummingbird population booms in spring and summer as migrants return from their southern wintering grounds.
Here are some of the hummingbirds that pass through Washington on their spring and fall migration journeys:
Rufous hummingbird
As described earlier, some rufous hummingbirds overwinter along the Pacific Northwest coast. But most migrate south to winter in the southern U.S. or Mexico after breeding farther north.
They migrate through Washington in early spring and fall on their way to and from their breeding grounds as far north as Alaska. Rufous hummingbirds are a very common migratory visitor throughout the state.
Calliope hummingbird
These tiny birds, the smallest breeding hummingbird in the U.S., migrate all the way from their winter range in Mexico up through Washington to reach summer breeding habitat.
They pass through in April and May on their way to mountain meadows and pine forests, and return south in late summer. Look for them in gardens and mountainsides during migration.
Black-chinned hummingbird
One of the most widespread hummingbird species, black-chinned hummingbirds breed across the western U.S. They migrate through Washington in spring and fall between their southern wintering range and more northern breeding grounds.
Broad-tailed hummingbird
With a bright red throat and metallic green back, broad-tailed hummingbirds are a migratory species prominent in mountain forests of the western states. They breed at higher elevations and migrate through Washington lowlands in spring and fall.
Rufous/Allen’s hummingbirds
In fall migration, rufous and Allen’s hummingbirds are nearly impossible to distinguish. Many reported rufous hummers migrating through western Washington in fall could actually be Allen’s hummingbirds headed south from their Pacific Northwest breeding range.
How can you help hummingbirds survive winter?
Here are some tips for how Washington residents can support overwintering hummingbirds and migrating hummingbirds passing through:
Put up feeders
Year-round feeders provide essential nutrition for Anna’s and rufous hummingbirds staying the winter, especially when flowers are not blooming. Clean the feeders regularly to prevent deadly fungus. Use a nectar mix of 1 part white sugar to 4 parts water. No food coloring is needed.
Provide fresh water
Hummingbirds use surprisingly large amounts of water even during winter. Drizzle some fresh water over leaves or rocks for hummingbirds to drink and bathe. Moving water from fountains or misters helps prevent freezing.
Grow winter-blooming flowers
Plant winter-blooming plants to provide live food sources. Hummingbird favorites include shrubs like winter honeysuckle, Ribes sanguineum, and flowering Mahonia species. Herbaceous perennials like Hellebores and Cyclamen also support winter hummers.
Let insects be
Spiders, aphids, and other insects in the garden provide essential protein. Avoid pesticides so hummers can forage for dormant insects on branches and under bark. String up insect cocoons for easy snacking.
Provide nesting materials
Anna’s hummingbirds build their nests and breed during winter. Leave out nesting materials like moss, plant down, feathers, or dog fur for them to collect as they establish their cold-season territories.
Offer man-made shelters
You can provide extra protection by hanging a small wooden hummingbird shelter stuffed with insulating material. Or drill 1 1⁄4-inch holes in the eaves of your home or garage to create warm crevice shelters. Just be sure to bird-proof your home against unwanted entry.
Avoid pruning trees
Resist the urge to prune trees and shrubs until late winter. Thick vegetation provides critical insulation and windbreaks for overwintering birds.
Conclusion
Hummingbirds may be tiny, but they have incredible tenacity when it comes to surviving cold winters. A few special species like Anna’s and rufous hummingbirds use specialized adaptations to overwinter in Washington’s harsh climate. They fatten up, reduce their metabolism, grow warm feathers, and take advantage of man-made feeders and shelters.
Other migratory species pass through the state in spring and fall, relying on the habitat and refueling opportunities our gardens provide along their incredible migration journeys between wintering and breeding grounds.
By understanding how these delicate-looking birds survive winter, Washington residents can better support healthy hummingbird populations in their yards and communities. Our actions to provide food, water, shelter, and nesting areas make a real difference for overwintering hummingbird species and migrating birds stopping by on their epic seasonal journeys.
