Winter is a harsh season for wildlife, but fortunately animal species have developed different behaviors and adaptations to help them survive the winter cold. Birds are no exception.
Fluffed-up feathers create warm pockets of air against the bird's body.
Bird adaptations are pretty remarkable, in my opinion. Feathers, of course, provide insulation. In fact, many birds undergo a fall molt to replace their feathers with a much denser set to prepare for the upcoming winter cold. When temperatures drop severely, birds will fluff up their feathers to help them create pockets of warm air against their bodies as an additional layer of insulation.
This white-winged dove is nestled in its fluffed-up feathers to conserve heat.
Some birds will draw their heads further into their feathers or tuck one foot into their bodies to reduce heat loss, or they might lower their bodies to cover both their legs. Speaking of legs and feet, scale-like coverings help protect the birds when they perch on freezing surfaces. Birds will shiver, as well — this helps generate heat (it’s why people shiver, too). And often during the day, you will find birds resting in spots warmed by the sun.
Doves rest all around my house when it's cold. They stay fluffed up and close by their favorite foraging spots.
Birds are warm-blooded and have an average body temperature of about 105 degrees Fahrenheit (40 degrees Celsius). They have a very high metabolism in order to maintain their body temperature, and as such they also have a faster heart rate, higher blood pressure, and faster respiratory system. It takes a lot of energy for birds to regulate their body temperature — much more so during the cold days of winter. That’s why birds will spend so much time at seed- and suet-feeders in the winter — they need high-energy, fat-providing sources of food to help them build up fat reserves and stay warm.
The smaller the bird, the higher its energy usage.
While many birds will visit seed- and suet-feeders in the winter, the importance of a diverse native habitat cannot be stressed enough. Wild birds need sources of nutrients that only nature can provide, and likewise many of the plants depend on birds for seed distribution.
Ground-foraging birds look for seeds and insects among the plants and soil -- a native habitat is critical for them and for all wild birds.
To conserve energy during cold nights, birds will lower their body temperature by slowing their metabolic rate. Many birds, such as chickadees or bluebirds, will roost together with other members of the same species in tree hollows or birdhouses, for collective warmth.
Ducks have a special circulatory network through their legs and feet that allows them to swim in icy-cold water.
Water birds, such as ducks, have their own physical adaptations to allow them to swim in icy water. Their circulatory system is a special network that transfers heat from arterial blood to the cooler venous blood, helping warm up the blood before it returns to the body — this help the birds avoid any heat loss and protect the core body temperature. Natural oils on the feathers keep them waterproof, another criteria for being able to swim in cold waters.
When temperatures drop below freezing, fresh liquid water can be scarce. There are birdbath heaters and other options for keeping water available to wildlife in winter. Also, moving water, such as a pond with a waterfall, is less likely to freeze quickly. If it has places for birds to land safely for a drink, it can be a great alternative if a birdbath freezes.
Birds need fresh water in the cold, especially if it freezes. If your birdbath freezes, help it thaw or set out more water!
Of course, many bird species just say, “To heck with this!” and fly south for the winter. Okay, it’s really not so much a choice as a necessity. Migration not only brings them to warmer regions, but helps them secure more food sources. Tropical vacation, anyone?
Sometimes during the winter, I wish I had my own feathers or fur to keep me warm. Nowadays, even my parka won’t keep me warm enough! Shiver….
Meredith O’Reilly gardens for wildlife in Austin, Texas, and writes about her garden adventures at Great Stems.
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About Meredith O'Reilly
Great article as always, Meredith.
Heard it was 70F one day in Austin, 30F the next. Just be sure you don’t send that cold due east , we hit 80F yesterday (sorry, had to say it). Today will barely make it to 70F… had to break out the sweatshirt again! Hope it warms up back to TX standards soon!
Loret recently posted..Bird in the Night
Snow is in the forecast, Loret — of course, it’s Texas, so I always take weather predictions with a grain of salt. I’ll be amazed if Florida remains untouched by the winter blasts affecting the rest of the country (of course, Florida has it’s own unusual weather patterns, so maybe not).
Interesting! I didn’t know about the ducks’ circulatory system. Isn’t nature amazing?
Kathy @nativegardener recently posted..Ah Santa Ana Winds
Nature never ceases to surprise me, Kathy!
Very nice article
Andy recently posted..Song Sparrow Amongst the Branches
Thank you, Andy! I visited your nature site — fantastic photos! Enjoy your birdies!
Given all the data coming in that a lot of dinosaurs had feathers, I’ve always wondered what a floofed up T-rex would look like. I love the way the little birds turn into grumpy little spheres in winter…you gotta wonder what that looks like at two-stories tall…
UrsulaV recently posted..Thaw Smell
The image of a fluffed-up T-rex is going to have me chuckling all day, Ursula.
I’ve heard that birdbaths are essential for birds in the winter so they can get the dirt and dust off their feathers. Dirty feathers aren’t very insulating. I’ve had a heated birdbath — just above freezing — on my deck for many years. Wonderful to watch year round, but especially in winter!
Love to hear your thoughts on this.
Marsha Stopa recently posted..Winter Blues Tip 14- Take notes when you change a winter routine
I know that for birds that don’t have waterproof feathers that being wet in the cold will make it harder to stay warm. But I don’t know much about the dirty feathers — especially when so many birds actually take dust baths. Interesting… I’ll have to look into it. This year made me realize that I’d love a heated birdbath, even if it doesn’t freeze very often here.
Lovely photos! Some of the birds who said “To heck with this!” and flew to GA for the winter are sorry they didn’t keep going. We keep getting snow and the poor southern bids are poofed up and miserable.
Just keep putting out that birdseed and peanut butter to keep ‘em going!