Anna's Hummingbird: the western hummingbird that stays all winter

The short answer

• Anna's Hummingbirds do not migrate out of most of their range. On the Pacific coast the feeder is a year-round commitment, and midwinter is when it counts most.
• Standard 4:1 nectar starts to slush at roughly 30 °F. Do not sweeten it to lower the freezing point: manage the temperature instead, with rotated feeders, insulation or a genuine heat source.
• The most important feeder of the day is the one hanging before first light. Birds come out of overnight torpor with almost nothing in reserve and need calories immediately.
• Anna's nest in December, January and February in California and the Pacific Northwest, which is the opposite of every other North American hummingbird schedule.
• The whole head glows rose-pink on an adult male, crown as well as throat. That, plus a scratchy perched song, separates it from every other western hummingbird.

On the Pacific coast the hummingbird question is inverted. Nobody needs telling when to hang the feeder in spring, because the birds were here in January and they were nesting. What people need is a plan for the fortnight when the nectar freezes solid by 3am.

A hummingbird that never leaves#

Anna's Hummingbird was once a bird of Baja California and the southern Californian coast. Over the last century it pushed north through the Pacific states into British Columbia and southeast Alaska, and it is now the default hummingbird of coastal cities from San Diego to Vancouver. Ornamental plantings that flower outside the native season, and a grid of nectar feeders, are a large part of why that expansion held.

Two consequences follow, and both are unusual.

It breeds in winter. Nesting starts in December in much of California and by January or February further north, timed to winter-blooming plants. A female may be incubating while frost is on the roof.

The feeder is a winter appliance. Feeder use peaks between November and February, exactly when most people in the rest of North America have theirs washed and boxed. If you are used to the Ruby-throated Hummingbird calendar in the East, none of its timing applies here.

What is actually on the menu#

Skip for this species: Black oil, Hearts, Striped, Safflower, Nyjer, Millet, Cracked corn, Peanuts (shelled), Peanuts (in shell), Suet, Mealworms, Fruit / jelly.

That is the whole list. There is no seed, suet or fruit fallback for this species, which is why a frozen feeder is a different problem than an empty seed tube. They also take large numbers of small insects and spiders for protein, and those come from the yard rather than from you, which is the argument for native plants and cover.

Overnight torpor, and why the dawn feeder matters#

A 4 g bird cannot carry enough fuel to shiver through a 25 °F night, so it enters torpor: body temperature falls far below its daytime level, breathing and heart rate slow, and the bird powers down on a twig until light returns. It can look dead, hanging motionless and sometimes upside down, and it needs 20 minutes or more of warming before it can fly.

What matters to a feeder owner is what happens next. The bird surfaces with its reserves close to gone and needs calories immediately, in the coldest, darkest part of its day. A feeder hung out at 9am has missed the moment.

Keeping nectar liquid below freezing#

Start with the number. Standard 4:1 nectar is roughly 17% sugar by weight, and our own calculation puts its freezing point about 2 °F below plain water: it slushes around 30 °F and is solid a few degrees lower. Sweetening is not a solution. A 3:1 mix buys a fraction of a degree and moves the food away from what the birds process best.

Practical notes that decide whether any of these work:

• The ports freeze before the reservoir does. A bottle can be liquid while the feeding holes are plugged with ice. Check the ports, not the level.
• Thermal mass helps. A well-filled bottle-style feeder holds heat longer than a shallow saucer, which is one of the trade-offs covered in saucer versus inverted feeders.
• Never use antifreeze, glycerine, salt or any additive. There is no safe chemical route to a lower freezing point in a bird feeder.
• Keep cleaning. Cold slows spoilage but does not stop it. Change winter nectar weekly and wash the feeder at each change, using the method in how to clean a bird feeder.

Behavior at the feeder#

Anna's are pugnacious and highly visible. A male takes a prominent perch above the feeder and holds it against all comers, including birds far larger than himself. Unlike most North American hummingbirds he also sings: a long scratchy, buzzing, grinding phrase from that perch, and once you know it you realize how many are around you.

The display flight is the other giveaway. A male climbs high, sometimes over 100 ft, then dives at the female or the intruder and produces a sharp explosive squeak at the bottom of the arc. The sound is made by the tail feathers, not the voice.

Expect one dominant bird plus quick raids from others. The remedy is the same as in the East: several small feeders where the guard bird cannot see one from another, covered on the hummingbird feeders page. Activity peaks in the first hour of light and the last half hour, and in cold weather a bird feeds almost continuously through the short afternoon.

Which hummingbird is it?#

Bulk and season help before the colors do. An Anna's is the heaviest-looking common hummingbird in most western yards, and it is the one still present in December.

Why yours stopped coming#

The feeder froze. Check the ports at dawn on any morning after a frost. Birds stop returning to an unreliable feeder within a couple of days.

You took it down for winter. The most common error in the range, and easily reversed.

The nectar aged. A month-old winter feeder grows mold even at 40 °F. Weekly changes, no exceptions.

One male owns it. You have not lost birds, you have lost visibility. Add feeders out of his line of sight.

Post-breeding movement. After nesting some birds move upslope and inland after summer flowers, so a July lull in a lowland yard is normal and resolves by autumn.

You are inland or east of the range. Anna's is a Pacific and Southwest bird. Interior states get Black-chinned, Broad-tailed, Rufous and Calliope on a summer schedule instead, which is a different feeder calendar entirely. Compare with hummingbird feeder timing.

The Anna's year#

• December to February. Nesting and peak feeder dependence. Freeze management matters more than anything else on this page. Pair it with the rest of your winter feeding setup.
• March to May. Second broods in the south, wild nectar arriving, feeder traffic still high.
• June to August. Flowers everywhere, some birds move upslope, feeder use dips.
• September to November. Numbers rebuild in gardens as wild flowering ends. This is when to get a second feeder and an insulating sleeve ready, before the first hard night rather than during it.

Batch sizes and mixing ratios for year-round feeding are in the hummingbird nectar recipe, and the nectar calculator will size a batch to the feeders you actually own.

Frequently asked questions#

Should I take my hummingbird feeder down for winter on the West Coast?

No. Anna's Hummingbirds are year-round residents from Baja north through California, Oregon, Washington and into British Columbia, and they nest in midwinter. Taking the feeder down in October removes a food source at the point in the year when natural nectar is scarcest and the birds are breeding. Keep one feeder running, clean it weekly, and have a plan for the nights it freezes.

How do I stop hummingbird nectar from freezing?

Run two feeders and swap them every hour or two on the coldest days, keeping the spare indoors. Bring the feeder in at dusk and hang it out before first light. Insulate the reservoir with a foam sleeve, bubble wrap or a thick sock, leaving the ports clear. Add real heat if you need it: an old-style incandescent bulb or incandescent string lights close to the reservoir, or outdoor-rated pipe heat cable. LED lights give off no useful heat and do nothing here.

Should I make the nectar stronger in cold weather?

No. Stay at four parts water to one part plain white sugar. A stronger mix lowers the freezing point by only a degree or two, which does not solve a real freeze, and it moves the food away from what the birds are built to process. Manage temperature physically instead, with rotation, insulation or heat. Our own arithmetic puts the freezing point of standard 4:1 nectar at roughly 2 °F below that of plain water, so it begins to slush around 30 °F.

What is torpor, and should I worry about a motionless hummingbird?

Torpor is a controlled overnight shutdown. The bird lowers its body temperature and slows its metabolism dramatically to survive a cold night on almost no fuel. A torpid hummingbird can hang from a twig looking dead, unresponsive, sometimes upside down, and needs 20 minutes or more to warm up enough to fly. Leave it alone. Do not bring it indoors or handle it. The useful response is to have nectar available and unfrozen at first light.

How do I tell an Anna's from other western hummingbirds?

Look at the head. An adult male Anna's has iridescent rose-pink over the whole crown and throat, not just a throat patch, and it looks dull bronze until the light is right. A Costa's has a violet gorget with long flaring corners. A Black-chinned male has a black throat with a thin violet band beneath. Rufous and Allen's are orange. Females are harder: a female Anna's is chunky and gray below, usually with a small central patch of red throat spots.

Sources and further reading

1. Anna's Hummingbird Cornell Lab of Ornithology, All About Birds Range expansion, year-round residency, winter nesting and identification
2. Feeding Birds Cornell Lab of Ornithology, Project FeederWatch Nectar ratio and feeder hygiene
3. Bird Feeding and Care National Audubon Society Nectar plants and year-round yard habitat in the West