How Do Birds Keep Warm in Winter?

Male_Cardinal_2-9-13

Male Cardinal giving a cute look.

What is most important?

Calories, and burning them, are the best way to body warmth in winter for birds, so you can see how our feeder feeding helps in this area with high calorie seed and suet.  Birds have other tricks under their wings to help as well. Let’s investigate…

Do you know how much of keeping warm is dependent on bird attire? Just like us, they put on their coat and boots’ so to speak.

  • They have independent ‘thermostats’ for their extremities, like legs, and their core. If we did, mom would not have to hound the kids on putting on the galoshes.
Female_Sparrow

Sparrow looking to Fly to the Feeder.

  • Their tiny, tooth pick legs are covered in scales which insulate and help to keep the bird dry.  It is surmised that scales, not being living tissue similar to our hair and fingernails, do not get frost-bitten, yet cover skin that does. But if you notice a bird squatting over its legs on its perch, that means it is really cold.
DoveFluffing

Cold mourning Dove puffing and crouching.

Did you know that Mourning Doves have lost toes to frostbite? That is because they have not lived in cold areas as long as tougher birds like chickadees, and have not yet adapted to colder regions.

Black_Capped_Chickadee

Black Capped Chickadee

  • Birds seek shelter in densely branched plants. Conifers are especially important for keeping birds dry and out of blistering winter winds. But they also provide food in the form of nuts and seed from cones – berries in the case of a plant like Juniper, cedar or cypress. Kind of like our bed and breakfast lodgings, huh? Many of these native plants provide shelter and a food source in winter, keeping birds warm inside and out. Safe from predators too!

Rain

  • Feathers have an oily coating that helps to insulate and keep the bird dry. All weather jacket?
  • They molt in Fall which will grow in the new set of feathers thicker and more numerous, further insulating the bird.
  • They fluff the feathers to add a layer of insulating air. Think our layering of clothes to keep warm. It adds pockets of air too.
  • Birds have a feast in Fall to bulk up before winter, adding excess weight and build layers of fat. Thanksgiving dinner?
  • They shiver like us, but when they do, use their flight muscles.

SparrowFest

  • Some roost in clusters in tree cavities to share body heat. They also use conifers for gathering.
  • They face away from the sun to expose the largest surface area to the warming rays, often spreading their wings too.
Cardinal_In_Snow

Female Cardinal on a branch.

Scientists have found…

Birds like chickadees take staying warm a bit further by entering a state of torpor to stay cozy during severely cold winter nights. During torpor, the body temperature may drop between 10 to 15 degrees, but could be as much as 50 degrees. Their metabolism slows down to conserve energy in a state called nocturnal hypothermia. Torpor is like a deep sleep that lowers heart rate. This saves a bird up to 20 percent of conserved energy.

Sparrow_In_Snow

Female Sparrow during a blowing snowfall.

Birds regulate their body temperature through metabolic heat production which means balancing the intake of energy with what they have eaten. They also reduce heat loss through their unique circulatory system of arteries and veins.

In many birds, arteries and veins in their legs lie in contact with or adjacent to each other in order to exchange heat and maintain temperature. Arterial blood is usually at body temperature when sent to the feet and runs along side the cooler returning blood in veins. This unique circulatory system keeps warm blood of arteries warming the returning cooler blood of the veins. It also helps explain their differing ‘thermostats’.

Cardinal_On_RoseBush

Male Cardinal on a rose bush in winter.

Bigger is better, but not always…

Typically larger birds deal better in cold weather than smaller birds, doves, as I noted above not being as adapted to cold, and the walnut sized chickadees that enter torpor to conserve energy, as an exception.

Have you ever noticed that birds who winter in cold regions are generally larger than their relatives who live in warmer regions? It allows them to conserve body heat more efficiently since producing that heat is a costly endeavor to the birds. It is no surprise that the Common Raven, Corvus corax, or the Blue Jay, Cyanocitta cristata, also a passerine bird in the family Corvidae, fly the skies here in the cold north.

Upcoming is interesting, important and gets YOU involved…

The first post in this series was on backyard feeding, entitled, So How Beneficial is Feeding Backyard Birds? . It looked at the pros and cons of the wildly popular hobby shared by 65 million US residents. I hope you are enjoying this series and maybe, learning something you didn’t know. The next post has things that you might find interesting too.

My next post in this series deals with disappearing sparrows. Although not attributed to loss from winter, they are facing a mysterious loss of population. I propose some theories myself.

How about you, can you add to the discussion with your hypotheses? It is a post to see if we as gardeners can help identify reasons why sparrows are in decline worldwide. I will tabulate your ideas and post them on March 20th, World Sparrow Day. Maybe we can help scientists look in new directions. After all, our ideas come via a wide world too!

Also, sparrows are beautifully featured, not something many do for this common bird which pesters our landscapes. I made them as pretty as the cardinals that visit, at least in my opinion. Hope you think so too.

Then a post for those not faint of heart. I follow a hawk around on his hunt. The drama unfolds in the wintry landscape, but does not play out as you might think.

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About Garden Walk Garden Talk

Love to photograph, paint, draw, design, garden, and pass on a few tips and ideas that I learned through experience as a Master Gardener and architect. I am highly trained in my field and enjoy my work each and every day. I garden in Niagara Falls, NY in zone 6-B. Find me at: http://gardenwalkgardentalk.com
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74 Responses to How Do Birds Keep Warm in Winter?

  1. waji says:

    o yeah…all the information given is true…some birds like humming bird generate heat by continuous flapping of their wing that help to generate energy…great post :)

  2. I love that photo of the sparrows. They might not be very spectacular, but they are such charming birds… I wish I had more in my garden, but then I feel confident that I shall have more or of them when the Hedgerow matures and gives them a good spot to retreat to.

    • My sparrow post is up next. I made all the sparrows really pretty, because like you I find them comical and fun. You maybe losing sparrows where you live. Worldwide they are disappearing, but not here for some odd reason.

      • Sparrows are still very common in Denmark, and there are loads of them just down the road where there is a dense hedge they can cavort in, so it’s simply a matter of my garden not having the right place for them to play around and hide. They will come once the Hedgerow matures!

        (They are common both in cities and in more suburban and rural areas, and there are loads of them in the nearby forest as well, so I will get my sparrows…)

  3. Donna, we were so happy to receiving birds in past weeks and have some new life in the area. I must admit I call all of them birds, because I am unable to identify them, shame on me! I love the picture of tree with many birds, is really original!

    • That tree is in my backyard. It is my Christmas tree that I took outside for shelter for the birds, and you can see they use it by the 100′s. In the photo, there is at least 40 birds, (or parts of birds) showing. That is only one side and a portion of the tree too.

  4. Donna–EVERY time I have looked out at my bird feeder this winter I have pondered the question that you have so thoroughly answered in this post! Thanks! –John

    • Birds are pretty amazing the way they have adapted to weather. Even the doves that are ill-equipped are likely changing physiology to live farther northward. I have never seen one without a toe, but I got that from a reputable source. But watching them, you can see they are cold, all puffed up sitting covering the feet.

  5. Laurrie says:

    I am not a bird watcher but I am thoroughly enjoying your posts, and learning a lot. I just love the picture of all the gathering of birds in the conifer — what a sight! All your photos are fantastic, with such detail! The personality of these birds shines through your lens.

    • Thank you Laurrie. Now if I could only get the flowers to have personality. Doing the birding posts, I have learned a lot too. One thinks to know so much, but especially with new finds in science, there is always more and more. Tonight I am attending a lecture on honeybees and CCD. I wonder what new developments the lecturer will tell us. I intend to push for information on the native bees too. The lecturer raises her bees naturally and has a nature preserve at her property.

  6. Christy says:

    Hi Donna….this is an absolutely wonderful post!! The picture of all the Sparrows is awesome….I would frame that one!! I knew that hummers went into torpor, but did not know about the other birds….guess it makes sense. After reading this it makes me even happier I have so many shrubs they can use to escape the elements.

    • It is funny, but that shot was hard to get. When they see me at the window, all the sparrows dart back inside the Concolor Fir in unison. It is just like in the cartoons where on cue, you see them then you don’t. I was lucky to catch them right before they disappeared. I have a post up next on disappearing sparrows. I never gave this idea a thought. Maybe they all are just hiding. :grin:

  7. HolleyGarden says:

    I have always wondered about their little legs and if they were cold! Now I know the answer. But, how sad that some of then get frostbite on their little toes! Your photo of the flock in the tree is fabulous! I hate the cold, so I really feel for these little guys having to stay out in the weather all winter.

  8. Fossillady says:

    Beautiful photos . . . I often wondered how the birds stay warm in winter and you provided a clear and well written explanation, thank you Donna! p.s. The shot with all the sparrows in the conifer is rather amazing and unique!

  9. This is why I keep the big old Japanese Yew that I otherwise think is ugly. It is my only evergreen, and good shelter for the birds. Also why I stock shelled peanuts in winter, even though they attract so many nuisance birds. I’ll have to think about the sparrows.

    • Yews are great plants for birds. I have smaller yews so they don’t do to much for them unfortunately. I feed shelled peanuts too, but also throw the Cockatoo’s food out for the outdoor birds. That includes seed in the shell. I am glad you might contribute an idea or two for the sparrows. What research has come up with is only part of the puzzle. There must be some primary reason for the loss of the birds.

  10. I never knew any of this. It makes me think of how vulnerable humans are to the elements without the things we make– our clothes and furnaces and blankets and houses.

    • Most people lost all their survival skills that was ingrained in us from prehistoric times. Now survival is based on technology and manufactured or built goods. I doubt I would be too fortunate tossed out into winter with only the clothes on my back. I would probably starve if I was even lucky to find warmth first. :sad:

  11. I learned a lot from this post! I knew hummers go into a state of torpor but didn’t know some of the song birds did that too. The goldfinches are already starting to put on their summer plumage here and it makes me wonder how they were impacted by our super cold weather this past weekend. Probably helped that they were busy at the feeders all day long! On colder days I often see our Rufous hummingbirds with their feathers puffed up keeping warm. They look really adorable. By the way, I hope you don’t mind that I mentioned your last post on my blog. Did a quick post on birds eating the blooms in my garden. I am very impressed with the number of sparrows on your conifer tree! Wow!

    • Our goldfinch are still dull. I am surprised to see them here at all. The hummingbirds must have been in deep sleep with the unseasonably cold weather you just had. Lucky they can get food at your feeder. You are lucky they winter on your property. They are darn cute. I visited your post and thank you. I enjoyed the birds feeding on the cherry blooms. Another look at feeding.

  12. gauchoman2002 says:

    Your posts are always such a fantastic combination of visual interest (with great photos) and great factual scientific information. I always feel like I learn something when I’ve read your posts, but you do such a fine job incorporating photos and good writing that I never feel like I’m reading a boring science textbook. And now when I see the nuthatches and chickadees and finches huddled in the pines and junipers, I’ll know that they’re chilly and likely in a state of torpor, so cool. Thanks!!

  13. alesiablogs says:

    Our climate is interesting in Seattle. I am a novice when it comes to birds. I am learning from folks like you now. : ) I do have a question. How long does their “sleep” state last for? Maybe you mentioned and I missed it, but around here I will see for example the hummingbirds disappear, but once in a blue while I see them pop up in the dead of winter! I was just showing my husband one the other day out the window! Our temps this winter have run mostly 40-44 or so. WE had some freezing this year,but not much. So far no snow as we live near the Pacific Ocean. We are an hour away from the beautiful mountains so we feel lucky in many ways. I will say my birds are not anywhere as beautiful as yours. Do you know if the more colorful birds like the colder climate? haha

    • Torpor is deep sleep, not like hibernation. A bird can wake from it, but is not always as aware of that around it, so a cat can snatch one. I think it lasts through the coldest part of a day or night, but they do wake periodically. Hummingbirds are more commonly going into the state of torpor. Seeing one in winter is pretty amazing. You must live in a beautiful place, it has a bit of every kind of landscape.

      • alesiablogs says:

        Yes. I have a crazy husband who put every bush known to mankind in our green belt over a 10 year period. He went on craig’s list and basically read where folks were giving up plants and bushes and we just had to dig them out if we wanted to..I have NO idea what all I have in my yard..Seriously! I do have blooms from usually March until the end of October so I like it.. I have one squirrl who cracks me up every morning . He literally scales this fence by my computer window and looks at me everyday. He always has something in his mouth..Its like he is saying…good morning mom–look at me! And off he goes. Wow I should blog about him …LMAO!

  14. rlogan1155 says:

    Great pictures and very informative. Am looking forward to your post on Disappearing Sparrows. As I watch out my window there are hundreds of house sparrows at my winter feeder, here in the Rio Grande Valley in south Texas. They are also, by far the most populous bird at my summer feeder in southern Ontario, Canada.
    Ruth from At Home on the Road

  15. What a great post. In the past three years, I have created a bird sanctuary here at my home near the Siskiyou National Forest in Southern Oregon. One particular Western Scrub Jay befriended me 3 years ago. I began to feed him/her and noticed that it’s mate is always nearby. The tame one comes right to me to get his daily peanuts, but the mate will only take a nut if I am approx. six feet away.

    Each year that I feed the birds, more Scrub Jays come to be fed. This year, the crested blue jays have appeared. I get anywhere from 15 – 30 jays at-a-time. I feed them between 8:30 – 10:00 a.m. They are all waiting on the fence posts and tree limbs, sqwaking up a storm when I appear each day.

    My Western Scrub Jays hate the crested ones and aggressively try to keep them away from me. In the past year and a half, for all 4 seasons, I have five species of birds nesting on my property and they all come to the yard when I put the feed out.

    I want to begin feeding the hummingbirds. Do you happen to know when the best time is to begin putting out a hummingbird feeder? Is February too early? There is snow on the ground here today and generally, it doesn’t start warming up until end of March or April.

    I will share a link to your post on our facebook page at: http://www.facebook.com/TheAnimalSpirits

    Many Blessings!

    ~Gerean Pflug for “The Animal Spirits”

    • Check with your local Audubon Society or Cooperative Extension for hummingbird arrivals.Your jay story is cute. They do become like pets when they see the person feeding each day. Thanks for checking out this post.

  16. As usual informative and a delight to see your images. I’m learning so much about birds that are different from ours in the UK. We are just waiting for the Skylarks that usually nest on the ground near the coast. The seabirds such as guillimot and razorbill will be coming to the cliffs to nest soon. They live at sea throughout the winter. look forward to your next post.

    • Your seabirds are an amazing group of birds. So different than what we see here with the gulls, cormorants and terns. Our cliff dwellers are hawks, but our Gorge is not nearly as dramatic as cliffs where you reside. The post on sparrows is one I enjoyed doing. I hope many participate with ideas.

  17. b-a-g says:

    Another outstanding post Donna. We don’t have cardinals in the UK, but I have fallen in love with the ones in your photos.

  18. Phil Lanoue says:

    All terrific but I especially love Mr. Cardinal!

  19. Emily Heath says:

    When I was a child sparrows were always about, now they are not. I put it down to concreting and paving over of gardens, giving sparrows fewer opportunities to find food. There is a film here by the Royal Society for Protection of Birds about possible causes: http://www.rspb.org.uk/film/8295218.aspx.

    • Thanks Emily for the video. I have added it to my post on disappearing sparrows and also credited you as the source link to the video. Many have credited it to environmental degradation in our cities, but it does not explain the fact that other songbird species are NOT experiencing the same fate. What about robins? Many live in cities. It also does not explain that here we do not have the same problem. I live in a city right along with the sparrows and we have an abundance of them. I think one can debunk most of the causes due to not affecting birds in general. To me, it seems to have a cause specific to sparrows only. That or it is numerous causes affecting a species compromised in a physical way. Like bees and CCD.

  20. What a thoroughly enjoyable read! I encourage any bird into my garden. My trees and shrubs are still very small but I am not without visitors and my garden would be quite a different place.
    Your photography is great too!

  21. diggingher says:

    Your pictures are extraordinary as always. Enjoyed the narrative too. We recently took a guided tour in the Florida keys and I learned that birds hold their wings open in the sun to dry. Some have less of the oil you mention which is better for diving and requires less dry time.

    • I know that wing spread is also for drying. I saw Cormorants doing it on a rock in the Niagara River this Fall. I also saw them in Maine doing it. The oil varies in bird species, and some only have it at their tail feathers. I am not sure why it varies. Some birds like my Cockatoo have powder on their feathers which does the same thing. The powder sifts through the feathers on a bird and acts as waterproofing and a feather conditioner when they preen themselves to smooth out the feathers..

  22. This is just a wonderful post, jam packed full of fantastic information about birds in winter. Your photos are just captivating, and I love the one with the flock of sparrows in the evergreen tree. Have plenty of sparrows at my house this winter, fat and sassy from my feed. Look forward to more fantastic posts!

  23. Jennifer says:

    Hi Donna, Your bird pictures just get better and better! When our boiler died and I went around the house wearing several sweaters and a coat, I got a whole new respect for birds and other wildlife that manage to survive in winter cold! This post is a wonderful explanation of just how birds manage to cope with the deep freeze.

  24. Carolyn says:

    Those little guys do keep us entertained… in every season!

  25. Fascinating again Donna…I wondered if birds entered topor and that explains why the chickadees are gone for our cold winter. Love hawks so I look forward to that post. As for sparrows, I adore them but not necessarily the house sparrows which are not really a sparrow but a finch from Europe that has taken over many of our native birds nesting sites. I wonder if house sparrows have anything to do with the disappearance of our lovely native sparrows.

    • Actually, torpor does not explain them missing for a season. It might explain a days worth of not visiting feeders if the weather is frigid. But birds have to eat so if weather persists where they cannot find food, well then they will have a problem. In my post on hummingbirds flying in the rain, birds will brave weather when necessary, and for hummingbirds, feeding is more necessary than most birds due to their high metabolism and tiny active bodies.

      House Sparrows have been here since: “Initially, eight pairs were released in Brooklyn, NY in either 1850 or 1851 by a single person/group of New Yorkers. Apparently they died before they could breed.
      Accounts differ, but it appears that in 1850 Nicholas Pike, Director of the Brooklyn Institute, purchased the first 8 pairs of sparrows from Liverpool, England (the cost of the trip was $200 per Barrows). He released the 8 pairs in the spring of 1851. They did not “thrive.”
      The following year (1851) he oversaw purchase of another 25 pairs of birds that were released along the East River. (Barrows [1889] reported 100 birds purchased by Pike from England released in fall the 1851 and spring 1852.)
      The rest wintered under the care of the Brooklyn Institute, and were released in 1853 in Greenwood Cemetery.
      Birds were released into Central Park (possibly to control canker worms infesting the trees [Lyacock 1966, Roots 1976]), Union Square Park, and Madison Square Park.
      In 1854 and 1858, the bird was introduced to Portland Maine.”

      From: http://www.sialis.org/hosphistory.htm. This site has much to know about HOSP. Also for Biology, look at: http://www.sialis.org/hospbio.htm

      I added these sites because at this point, based on taxonomy, the HOSP is an Old World Sparrow. I contacted someone from Audubon on this question of it being a finch. It is not a finch until it is proven genetically to be one, which appears to be unlikely. The taxonomy of the birds are dissimilar. Sparrows were also believed, (not certain) introduced to Europe initially from Africa, and have had a very long association with humans.
      Old World Sparrows found here: http://allaboutbirds.org/guide/browse_tax/41/
      New World Sparrows and Allies: http://allaboutbirds.org/guide/browse_tax/24/

      It is unfortunate that sparrows at times take over nesting boxes of birds like blue birds, but generally, blue birds are not predominately a city dweller like the sparrow.

      I am uncertain on your last question as to whether they have affected the native sparrows. My guess it is more a situation of disappearing habitats than anything on most native species, rather than displacement of one over another in birds. HOSP are losing numbers throughout the world and I question this in the next post.

  26. Marguerite says:

    Great information in this post. I often wonder about water birds and how they manage to survive in the depths of winter. The scaly legs you talk about must be part of the trick.

    • Water birds I am assuming have the same ways in which to keep warm, maybe even more. Their feathers provide buoyancy so I bet that added feather structure keeps them warm too. Not to mention, most are bigger birds, storing more fat. Since some of them are black and white, the black would keep heat in and absorb the sun’s rays. I am just guessing here, but it sounds likely. If you want to know how water birds are coping with climate change (plus all other birds in every regional habitat) download this report. The State of the Birds 2010 Report on Climate Change. It is interesting reading and coming up in my next post. http://www.stateofthebirds.org/2010.

  27. Denise says:

    That tree with all the sparrows is wonderful! I noticed sparrows hiding in a little round bush this morning. It must be cosy inside those evergreens.

  28. Oh my, that was a flashback to undergraduate animal physiology! I remember when I first learned about the counter-current heat exchange mechanism in bird legs, although that was in the context of “why don’t duck feet stick to frozen ponds”. I’ve done a lot of oil spill response over the years, and the first thing we teach volunteers is that oiled feathers lose their insulation value. As birds have little to no subcutaneous fat reserves, hypothermia is a great, and immediate, risk to them in that condition. Spills aside though, it’s amazing the conditions that birds can survive in, especially some of the tiny species, like hummingbirds. By the way, I love that photo with the tree loaded to the breaking point with sparrows. I don’t think I’ve ever seen that many in one place! Amazing shot!

    • It is so wonderful you putting in the time on oil spills to clean the birds and educate others. Thank you. Those images of oil-soaked birds is haunting. I cry for the wildlife in these hopeless, senseless situations and wish I too was within the area to help. I always buy Dawn for this reason.

      I remember learning why ducks feet don’t stick too. I also remember questioning this when I first got my cockatoo. I was curious as to all things about the bird.

  29. Hi! Love this blog! Amazing pictures! Thanks for writing!

  30. Helene says:

    So many people have said this before me, but I just have to agree; that picture with the sparrows in the tree was just amazing! I am still new to bird watching/feeding/photographing, and I am learning so much by coming here, thanks for all the info, so interesting!

  31. Thank you, hope the posts help you in your backyard birding.

  32. Ginny says:

    Donna, I love this post and the previous one in the series. I love the birds as much as the plants in my garden. I feed them year-round at feeders and have multiple houses for them in addition to man bird-friendly plantings. Will look forward to your next post!

  33. Yours is a colder climate than mine and while sometimes the birds fluff up like your photos, it isn’t often. I look forward to the hawk post ( probably already up)

  34. YellowCable says:

    Very nice shots of these cute creatures.

  35. Such amazing pictures!!!

  36. Hi Donna,
    These photos are absolutely STUNNING! Did you take all of these bird photos yourself? What equipment do you use? I’m so happy I found your blog–it came up in my Zemanta suggestions for “Related Articles” as I was writing my post on mourning doves, so I did indeed include the link to your post–here it is: http://www.joyfullygreen.com/2013/03/mourning-doves-true-love-birds.html.
    Count me in as a new subscriber!

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