Anna’s Hummingbird: Our winter hummingbird

How Anna’s Hummingbird became a regular in winter at backyard feeders in the Pacific Northwest
By Gregory A. Green | Published: 8/9/2013

WinterHummingbirdLayout When Irving Berlin wrote the song “White Christmas,” I doubt he was dreaming about hummingbirds. The tiny birds fit no more in a Christmas motif than a Scarlet Macaw. Yet as seven inches of the Yuletide white powder buried my Seattle suburban garden, there she sat among the snow-laden branches of a red huckleberry bush — a female Anna’s Hummingbird.

She was keeping up a constant guard over a nectar feeder hanging off the back porch. Every few minutes, she flew to it for a shot of liquid sucrose and then settled back on her tiny perch protruding from the snow. Occasionally, she lifted off to drive away an intruder, always toward our neighbor’s feeder, where I presume a second hummingbird held territory. But mostly she just sat in the cold, turning sugar to fat and waiting until it was again time to get another drink from the plastic flower.

And she did this every day during a winter week of snow, wind, and temperatures well below freezing. For a couple of days, her tiny feet gripped not the thin branch but rather the rime of ice that encased it. Both feet and branch were often hidden under a downy puff of feathers.

So why was this little green jewel — seemingly much better suited to the tropics and its profusion of year-round flowers than the cold winters of the Pacific northwest — still here? The bird’s body size alone, weighing no more than a nickel, works against it, as its high surface-to-volume ratio makes retaining heat difficult. Certainly, it requires the high octane of liquid sugar to keep its internal engine running. But why bother when a better life is waiting in the sunny South?

Of the four Pacific Northwest hummingbirds, Anna’s is the only one that doesn’t always migrate south to warmer climes in the winter. Rufous, Calliope, and Black-chinned Hummingbirds have enough sense to leave for Mexico and the Gulf Coast by late summer. Most of the males are gone by early July.

The three migrants largely follow a racetrack route developed since the last Ice Age. In early spring, they fly north up the valleys and along the foothills of the Pacific slopes of the western United States, dropping off along the way to nest but always capitalizing on the spring flowers as they come into bloom. As the lowland flowers begin to wane in the summer, the birds move up in elevation to the alpine meadows of the Rocky Mountains and Sierra Nevada, where the flowers are at their peak. Then they follow the mountain spines back down to Mexico, where they spend five to six months competing with nearly a dozen other hummingbirds for chuparosa (Justicia californica) nectar. The oval route allows the birds to follow the latitudinal and elevation changes in the peak flowering season, much as wildebeest follow the grass-sustaining rains in a circle around the Serengeti — a logical system fine-tuned over thousands of years of natural selection.

As for Anna’s wintering in my backyard, did thousands of years of natural selection create a hardy little animal specifically adapted to cold Pacific Northwest winters? Probably not.

Who was Anna?

Anna’s Hummingbird (Calypte anna) was first described in 1829 by René Primevère Lesson, a French naval surgeon and naturalist. He collected the bird for the private collection of Prince François Victor Masséna, the 2nd Duke of Rivoli, and named it for the duchess of Rivoli, Anna de Belle Masséna.

Truth is, the hummingbird has been overwintering at higher latitudes only for the last few decades. Prior to the 1930s, it nested no farther north than San Francisco Bay and was not reported north of the Oregon border until 1944 (four years after publication of Ira Gabrielson and Stanley Jewett’s classic book Birds of Oregon, which said nothing about Anna’s). The bird reached Seattle in 1964 and today breeds on Vancouver Island and is found in southeastern Alaska regularly.

In their core, albeit historical, range in the Santa Monica Mountains of southern California, Anna’s can depend on species of currant or gooseberry to be flowering at any point in the year. The birds may have to move up- and downslope to catch the varied bloom, but for the most part, they don’t need to travel far to find flowers. They also begin breeding at the onset of winter rains to stay a step ahead of other species of hummingbirds and to time fledging to the peak of the spring currant bloom. So, if Anna’s have it all worked out in southern California, why the Grapes of Wrath-like immigration north?

Their journey north appears to have begun with the appearance, and then northward establishment, of another species: the blue gum eucalyptus (Eucalyptus globulus) from Australia. First introduced to southern California in the 1870s for shade, lumber, and railroad ties, and later used for lumber and orange-grove windbreaks, the tree is now naturalized in the coastal areas of southern California and the San Francisco Bay region. Areas of the state that were once treeless plains are now savannahs or long-abandoned plantations of blue gum.

The tree’s nectar-rich flowers bloom in the winter. Anna’s Hummingbird is one of only two native wildlife species that appear to find value in the tree. (As you can read in this PDF, Monarch butterfly, which uses it as a winter roost, is the other.) Taking advantage of a developing urban horticulture in the Los Angeles Basin, Anna’s found it could now live year-round in the lowlands of southern California and later move north to the Bay area as blue gum groves there matured. Ornithologists Joseph Grinnell and Alden Miller published The Distribution of the Birds of California in 1944. Because of the above factors, they wrote, the Anna’s 1940s population had greatly exceeded the original. The little mountain bird had become a common flatlander.

But blue gum trees aren’t common in Oregon and Washington, so why did Anna’s Hummingbird continue north? Part of the answer is hanging off my back porch. Nectar feeders in urban areas provide a super-rich food source. Why fly around licking dewy drops of nectar from scattered flowers full of bees when a whole quart of the stuff is just hanging there? It may not be entirely natural, but it is the same sucrose sugar that the hummingbird favors. And it is well worth defending.

Add to that the growth of some urban areas of the Pacific Northwest. Development has replaced the native conifer forest with incredibly rich and diverse garden flowers, many of which bloom earlier or later than native flowers, providing a longer plant-nectar feeding period for hummingbirds. Some flowers, such as winter jasmine, viburnum, sweet box, witch hazel, Oregon grape, and heather, even bloom in winter.

In their original southern California habitat, Anna’s Hummingbirds rely on chaparral and gooseberry, both with long growing seasons, but they readily forage on exotics provided by local nurseries. The birds have simply shifted north to capitalize on the profusion of urban gardens in the Pacific Northwest. The Seattle area’s locally large populations of eastern gray squirrels and American Crows have similarly adapted to the regional shift from conifer forest to the combined native and exotic deciduous trees.

How to care for overwintering Anna’s

Here’s what to do if an Anna’s Hummingbird chooses to stay in your yard this winter.

Do not adjust your sugar solution. Keep the ratio of sugar to water the same: 1 part white sugar to 4 parts water. Do not add dye.

Hang more than one feeder. Anna’s Hummingbirds don’t share well. Multiple feeders will reduce competition.

Keep the solution from freezing. Rotate your feeders throughout the day, or experiment with heat sources: Seattle Audubon Society suggests stringing Christmas lights around or under your feeder, hanging a mechanic’s trouble light near your feeding station, taping a chemical hand warmer to the feeder, or wrapping plumber’s heat tape around your feeder.

Offer water. A heated bath can be a big help to all birds, including hummingbirds.

Source: Seattle Audubon Society

So why do Anna’s Hummingbirds stay the entire winter? It may simply be that they haven’t yet established a racetrack route comparable to the one perfected by other hummingbirds over eons. Alternatively, flying back down the urbanized lowlands to southern California during the late summer might carry them past too many dried-up flowers. You could get mighty hungry traveling to southern California if all the roadside cafes along the way were closed for the season.

Anna’s also take advantage of the hummingbird’s motto “When things get tough, the tough go to sleep.” A hummingbird in torpor can drop its body temperature from about 40°C to about 9°C (from 104°F to 48.2°F) and reduce its respiration rate from 245 breaths per minute to 6. It can even suspend its breathing for up to five minutes. The metabolic rate of an Anna’s during torpor can be 300 times lower than when in flight. The savings are significant; they can help a hummingbird sleep through a severe weather period.

A typical winter day might find an Anna’s sucking sugar, slowly turning it to fat, and then going into torpor during the night, living off the stored fuel. An Anna’s can gain 16 percent of its body weight during the day and then burn it all off during a cold night. (Imagine waking every morning 25 pounds lighter.) The fluctuation is extreme enough without adding the energetics of flight. Regardless of the season, awake and flying, a hummingbird is always just a few hours from starvation.

So, unless you are following a mountain migration route south that allows you to fly flower to flower as other hummingbirds do, it is best to keep your metabolic engine parked in the garage as much as possible. This is especially important if, during flight, your heart beats 1,260 per minute, by far the highest rate of any vertebrate. The alternative is running out of gas long before you reach the wintering grounds.

Anna’s Hummingbirds trying to survive a cold winter also have another item in their bag of tricks: They eat insects and spiders. They will hawk flying insects, glean tree hoppers from leaves, probe crevices for spiders, steal captured insects from spider webs, and pluck trapped insects from tree sap. And you can assume that even more insects and spiders await discovery in winter by hummingbirds that know where to look.

It is not just “supplemental” food, either. Hummingbirds need protein and don’t get it from a diet of nectar alone. One researcher calculated that, during the summer, a hummingbird needs to eat more than 30 small flies per day. How much protein a bird requires during the winter is unknown, but it may be less, especially if it is more sedentary or more adept at finding insects than we imagine. (Hummingbirds will also suck the sap from sapsucker woodpecker holes to supplement their sugar needs.)

Regardless of how Anna’s Hummingbirds survive the winter, they have now become year-round residents in the urban areas of the Pacific Northwest, along with our local towhees, chickadees, and juncos. They are the new iridescent green ornaments on our Christmas tree, and they no longer look so out of place in my winter garden.

Gregory A. Green is a wildlife ecologist and photographer. He has served as associate editor for Northwestern Naturalist, Journal of Wildlife Management, and Herpetological Conservation and Biology and has written for Natural History and other magazines.


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  • Dzhgoody

    This little guy has been hanging out on the brick wall of our house today as it is snowing. I put a pie plate on a ladder with their sugar water. I keep it thawed by heating a brick and putting under it.

  • camphoneguy

    Lost one today in this extreme cold we’re having.

    • Jake Plummer

      aw, poor thing

    • linda

      I live in Tonasket Washington, had to cry when I saw this poor little one. I look forward to seeing these little beauties every year

      • Bonnie B.

        So sad when I see a picture of one that did not make it. I had one that hit a window & broke his neck (I think). We had a large picture window. I held him. He wasn’t just stunned he was dead. He was such an adult male Ruby-throated. Yes….some do not make it…:-(

  • Oneofate

    Hi there: We live in Campbell River, British Columbia. We fed Anna’s all winter this year for the first time. Feeder is under the west facing eave and about 18″ outside our dining room window. Also have a very large holly tree about 15′ away where they like to roost. Excellent spot to see the action and take photos.
    I suspect there were more than one pair in the area as we often had a bird being chased off the feeder by another. The male and female we saw regularly deemed to share the feeder just fine but appeared not to want to share with strangers.
    This morning we observed a male rufous at the feeder for the first time this year. Haven’t seen “our” Anna’s today at all and fear the Rufous may drive them off.
    Any advice? Should we put up another feeder to give the Anna’s a chance? Close by or out of sight?

  • I have had an Anna in my garden for 5 years plus. She would not let another Hummingbird in to feed. This Summer another bird turned up once in awhile and then over the last few weeks the two of them have been circling each other and finally fed on the same feeder several times. When do they mate? Is this her mate? When are there babies? In Winter my original Hummer turns up at first light so I have two feeders and set my clock (hard to believe) and run out with a fresh one to replace the frozen one. She turns up and sits under cover on the patio and feeds and then sits on my Wisteria vine also on the deck so she just goes back and forth about one foot, all under cover. At dusk she leaves and I think is in the conifer free about a block away. So cute. Is that other bird her mate? Does anyone know. I do up the sugar right about now in the feeder as it is cold at night. Karen.

    • Mary Bachmayer

      I do the same, bring the feeders in at night and put them out at first light. It breaks my heart to see the little pixies try to feed from a frozen feeder.

      • Blackgriffin

        Buy some hand warmers at Walmart or Lowes. Cut the tops from men’s tube socks. Use the sock tops as cozies (as in tea cozy) to hold the hand warmer to the part of the feeder that holds the liquid. The warmers last for about eight hours. Plus, yes, bring the feeders in at night. But a lot of the time, it’s still pretty cold in the morning, so you might need to use the warmers.

  • Sylvia Drummond

    This is the first year in 21 yrs. I have lived in my condo that I have had hummingbirds.This is winter in BC Canada.Oct.I will try to keep them as long as they want to stay.The feeders are out and there are 2 HB.

    • carole

      We live in Lake Oswego, Or…have had Anna’s for about 6 years. Several females and one male. In winter I bring the feeders in and alternate during the day when its freezing. They can be confrontational and can challenge a cat not knowing the danger. We found a little one lying on the deck…put her up on the table….I went out to stroke her and she awoke and flew away!!

  • Kathleen Corbett Peters

    I live in the Pacific Northwest and just started feeding the hummingbirds this past summer. Now that it s getting very cold, I wanted to find a way to keep feeding the hummingbirds without having to nectar freeze at night. I did some research online, and found a company in Oregon that makes heated hummingbird feeders. I have two of the feeders and the hummingbirds love them. Please visit

    • Creg Crones

      I made my own heaters just like these, they are very easy to make. I also use an in line thermostat to turn the heaters off and on according to the outside temp (on at 35, off at 45). We have 5 feeders out now and have about a dozen Anna’s this winter (Graham WA).

  • laura

    an easy way to beat the freezing of your feeder, bring it in at night and put it back out in the morning….easy and no mess….

  • Huyen Lan Nguyen

    I live in North california and I have anna’s hummingbirds in my front and backyard. Each of them occupy and defend its own feeder. I tried to post my pictures but I do not know why it does not work

  • Huyen Lan Nguyen

    I live in North California and these are my anna’s hummingbirds in my front and backyard.

    • linda

      Wow Huyen, it sure is a pretty one!

  • Just sayin’

    I haven’t seen our Anna’s in a couple of days. For the last couple of weeks they were more active than usual, you could see them out there all day long. Have I lost them? They may still be coming but we have not noticed them, and the feeders are visible throughout the day..

  • Laurie Norberg

    We live in Montana and have had our first Anna’s…a subadult male who has stayed the winter. We did have to up the sugar content to prevent it from freezing in a couple hours, and rotated feeders every couple hours whenever possible. This little guy survived some major cold snaps…with wind chills in the -20-30s.

  • Shannon

    I think I may have seen a male buzzing around in the hills of Bellingham, WA. Is that possible? It was tiny, made a loud buzzing sound and I saw flashes of red and green…

    • Christine M.

      Very likely!

  • Jonathan Newman

    I have hummers all year round in Pt. Grey Vancouver for over the last 10 years and when the temp dips below O degrees C. at night/day I place a soup can until the feeder secured with two wires to the feeder. A 10 watt light bulb (small ones for appliances) with a hole drilled to hold a lamp socket at the can bottom. Works great and the birds now have a nice warmer nectar drink. Just a suggestion.

    • lillylangtree

      Great idea Jonathan. So far the food hasn’t froze here in Northern California, but I get up early and put warm food out for them in some of the feeders. Another idea someone gave me was to put christmas lights around feeders. I wonder if solar would work to keep the food warm?

  • lillylangtree

    I have so many hummingbirds all year, I have to make a gallon per day here in Northern California. We love them, there are swarms, lol. This photo doesn’t even depict the amount of hummingbirds that live here all year and every year there seems to be even more.

    • Renee’ Allie

      I too have huge charms of hummingbirds. In winter, here in Camarillo, Ventura County, CA, I have 24 feeders out which hold a total of 6.5 gals of nectar. I make & distribute 2 gals per day. This increases to 30 feeders in summer & 3 to 4 gals per day. I read above NOT to increase sugar, but I do, in the winter, I use 3 to 1 & rest of the year 4 to 1. I saw a hummer upside down under the eaves today. It was there for several hours during daylight hours. My guess it just didn’t make it through the night. We have had some really unusually cold days & nights over the past couple weeks. Makes me worry about the hummers.

  • Judith Anderson

    We live near Vancouver, BC. We have had Anna’s at our feeder for over a year but we will not be able to keep the feeder going this winter. When should we discontinue feeding (it is now late August) to encourage them to move elsewhere, before it gets too late in the season? Thanks.

    • Bonnie B.

      You can keep feeding them as long as you want to. Some that are too old or sick to make the migration you could be saving their lives. I would not up the sugar solution. I am in Tx near Dallas & mine is still up for any Rufous or other late ones coming thru on their route to Mexico or beyond. I have not personally seen any since )ct. 19th, 2016. I usually have none staying the winter.

  • Kenneth Reister

    Anna’s humming birds have been over wintering or returning to Washington State very early for much longer than a couple of decades. I recall seeing Anna on February 19, 1966 while I was hiking the trail to Lower Lena Lake on the Olympic Peninsula. The bird had been in a cave when it spied my dad’s red backpack. Dad’s red backpack was irresistible to the hummer. It just had to come in close to check it out before being sorely disappointed and flying back to the cave. Further, I recall, it was snowing at the time. All of us present at the time were very surprised.

    • Christine M.

      Poor baby. The hummer must be starving 🙁

  • Anthony Speed

    Living in Courtenay B.C.

    This past summer i thought id place a humming bird feeder up on my deck.. 3rd floor apt. I thought… ok ,,, maybe i might get a bird or two to come around now & then…. Well I have had the pleasure now of watching 2-3 regular Anna’s at the feeder…& im hooked ! LoL

    One of them regularly sits in a couple of places on my deck… waiting for any others that come by, to then screech loudly & chase them away…. However now that its gotten below freezing… ive noticed for the first time, two of them feeding at once. The other day the nectar was frozen, so I made a fresh batch, cleaned up the feeder & now to help prevent freezing i am taking the feeder in at night & putting it back out in the morning before daylight starts….. i also put a red wool sock over the feeder reservoir… seems to be working well so far…

    Now that its colder i do notice them taking much longer drinks…. They are just amazing to watch…. & as a result, like i said, i am now hooked on humming birds….lol
    Initially this “new hobby” i started with a 7 dollar typical feeder & didnt really expect much….however i must say this pretty cheap investment has made for so much pleasure…. now that im “hooked” ….come this spring… I think a newer & more efficient type of feeder is in order… maybe even a couple of them….& to also hook up some sort of heating system to keep the nectar warm in the cold months…a bit of a challenge as i dont have any power on the deck… but maybe something solar powered…..

  • Lee-Ann Ruttan

    I live in Sooke BC, and I get 20 plus Anna’s at my three feeders all winter! They are amazing to to watch. I go through 6-8 cups of sugar water a day! I have seen them poking in the wood Pecker holes in the trees. I have hung suet, but have not seen them eating any yet?

  • Dennis Brown

    Tonight I found a female Anna’s sitting on the feeder. It’s been very cold getting into the lower teens at night and I’ve been changing the frozen feeders during the day with warm ones (3-4 changes a day) since the cold snap. I thought it was strange that one was at the feeder so late in the evening (dusk).so I investigated.

    She was very cold and in stress so what can I do? In the guest bath there is a small side sliding window so there is my heat source. I put a hook up under the eave at the small bathroom window, unhooked the feeder she was on and rehung it right in front of the window. She did not move one bit, it was like she knew I was there to help. I closed the door to the bathroom so the forced air heating would go out through the window warming her and her roost for the night. I then thought, she’ll get cold when the furnace is off so I hung a clip-on fan on the shower curtain rod and pointed it at the window. This way she has some heat when the furnace is off. She was moving (breathing) when I turned out the light. Hope she makes it.

    I had another close encounter with a female Anna’s last summer. I was watering the flowers and this little girl came over and lit on my hand, just sitting there looking at me and me looking at her. This went on for 30 to 45 seconds, I would move my hand to spread the water and she just sat there, not bothered a bit.

    Incredible animals

  • Notsothoreau

    I can’t identify a hummingbird that is a frequent visitor. It seems to have a brown body, blue wings and a red patch on the chin. It makes a clicking noise. I bring the feeder in at night when it’s freezing. It expects me to put it out by 8 am. This morning, when I was putting it out, it flew within inches of me.

    I am guessing that it’s one of the common varieties, and I’m just not seeing it clearly enough to match it up. Any ideas?

    • Autumn Again

      Brown body sounds like a rufus hummingbird. Their wings make an almost bell-like tinkling or ringing sound as they fly. Many hummingbirds make a clicking sound when excited, or foraging. Check photos of female hummingbirds also. They are often a bit duller. The female Anna’s is still green over the back, but most have at least a few pink/red feathers at the throat instead of a pink forehead and throat like the males have. I have seen a few females with a full pink gorget, but never any with color above the bill. Many people,would mistake female Anna’s for males. Also, some hummingbirds do hybridize where their ranges overlap. I’ve seen some odd hybrids whose parentage I couldn’t deduce from their appearance.

  • Autumn Again

    One evening, in the subfreezing winter of 2016, when the male Anna’s who usually guards my Oregon feeder apparently didn’t have the strength to run-off them off, I was watching 2 miserebly cold hummers sitting at my feeder when one suddenly keeled-over backward onto the balcony railing with its legs in the air like a dead bug. I ran out, scooped it up, and held it to my chest as I warmed some 2:1 nectar for it. It slowly came to life, so I put it in a cage with a feeder of double-strength nectar, and there it lived for the next 8 days until the worst of the cold snap past. Then I released it. It felt fat and healthy when I let it go. I hope it made it through the winter. Others did not.

    I set feeders all along the bicycle path near my home to keep the others fed and prevent fights until the flowers started blooming that spring. Going out just before dawn, at noon, and again at 3 PM to replace frozen nectar with fresh along a route that wasn’t even my property was a pain in the neck, but I don’t think the birds would’ve survived the winter without it. I used double-strength nectar until we came out of the deep freeze. I wish this article said WHY we shouldn’t adjust the sugar to water ratio. I did, and I think it was necessary to get them through an extremely harsh winter.

    • francis iceberg

      Anything more than 4 parts water to 1 part sugar will poison the birds.

      • Autumn Again

        In what way is anything stronger that 4:1 nectar poisonous to hummingbirds, and where is the research? What is this belief based on other than internet rumor?

        I fed my resident birds 2:1 last winter, and I used to have a neighbor who fed dozens of birds a 2:1 nectar all summer. They come back to her feeders year after year, in swarms. My resident male has been around for years, doing the same behaviors he’s always done, despite having 2:1 food last winter to get him through the cold spell.

        • washingtonmink

          4:1 water/sugar is metabolically & nutritionally perfect. Higher concentration can harm kidneys & metabolism. why would you want to take a chance on harming this precious creatures when 4:1 is known the be a correct formula?

          • Autumn Again

            You’re still just repeating internet rumor. Show me a study.

            4:1 nectar isn’t “nutritionally perfect.” Hummingbirds also need protein, fats, vitamins, minerals, etc. just like any animal. Nectar varies widely in nature, and hummingbirds are known to also eat fruit, sap, insects, spiders, and even maple syrup when there are other nectar sources available (i.e., not out of necessity).

            Here in Oregon, hummingbirds drop dead in the cold because they burn more calories than they can take in from cold, 4:1 nectar.

          • MissRivka

            4:1 is what every scientist and bird expert all agree that they can use the best. get a heated feeder if you need to, but don’t change ratio, it can cause kidney issues and dehydration. it would be like us only drinking coke and salty foods all day and never any water,

          • Autumn Again

            A heated feeder isn’t going to address the birds’ energy needs.

            If anyone can produce actual scientific documentation that 3:1 or 2:1 nectar is somehow dangerous to these birds during the winter, I’d be interested in reading it. Otherwise I’m tired of reading and replying to the same old mindless conjecture.

          • MissRivka

            So i went looking for the info i had read years ago and ended up reading s ton. I believe you are correct and i was falling prey to an echo chamber. I just spent 30 minutes readig multiple sources that have serious credibility say that 3:1 is perfectly in the norm of the flowers they go to and that in the winter even 2:1 is not overly bad. It does spoil faster and may leave them thirtsty when its hot out, but otherwise its safe. Thank you for spuring me to go read and learn more.

          • Matt Mendenhall

            I asked our “Since You Asked” columnist Julie Craves about this, and she writes that she found “multiple peer-reviewed papers that give the mean sugar concentration of hummingbird-pollinated flowers as around 20-25%. Higher concentrations are found more often in bee-pollinated flowers, although hummingbirds will sometimes visit them as well. Experiments using feeders found hummingbirds tend to prefer a higher concentration of 35-40%. This corresponded with a presumed balance of energy gained with the efficiency of their method of nectar uptake by capillary action. As concentration increases, so does viscosity which makes capillary uptake more difficult. Viscosity is also temperature-dependent, increasing with decreasing temperatures. One study notes that in Costa Rica, hummingbird pollinated flowers in the cooler mountains have lower sugar concentrations that those at lower, warmer altitudes.

            So, we see where the 4:1 ratio of water to sugar comes from, and we can also see that at high concentrations of sugar, nectar becomes less efficiently consumed, especially at lower temperatures.

            I’ll add that the preference for higher concentrations found in experiments also involve other factors such as the unlimited nature of nectar in feeders, that flower nectar has components beyond just sucrose and water, and various aspects of flower morphology and nectar have evolved to maximize the benefit to both plant and bird (which usually involves a compromise).

            I did not in my cursory look find anything that indicated higher concentrations of sugar were “poisonous” to hummingbirds. However, at higher temperatures spoilage occurs more quickly and may create dangerous situations due to fermentation, fungal growth, etc.

            While it is presumably okay to offer a hummingbird coming to a feeder in cold weather a higher than 20% concentration, it might create problems with viscosity. The other issue is that high concentrations may reduce the amount of water available to the bird if there were no unfrozen water around, and that birds in poor condition may be particularly prone to difficulties in processing high levels of sugar and dehydration from reduced intake of water. Given all the evidence, I think the 4:1 concentration is a great rule of thumb to stick by all year long.” — Matt Mendenhall, Editor

          • Autumn Again

            It is hard to sort facts from internet rumor. Thank you for looking that up, MissRivka.

  • Norm Bolser

    I discovered these wintering over birds years back when I left the hummingbird feeder out way past the usual season – it wasn’t empty, why bring it in? Much to my amazement there were still birds coming to it. So I started leaving it out all winter and put some heat tape on it so it won’t freeze. I use a 1:1 mix by volume of sugar to water and the color is there for me, not the birds. I like looking at the color. I’ve tried every color imaginable greens and blues and purples, still the birds don’t seem to care. And I haven’t seen any dropping dead from a little food coloring. Right now I see 4 hummers coming around. They don’t seem so territorial in the winter. They sure seem to like the warm (relatively speaking) nectar.

  • Norm Bolser