Weekly Photo Challenge: Warmth – Coping like a bird

warmth

Our local meteorologist reported, “Days of cold, strong east winds will take hold Monday afternoon and last through the day Wednesday.”

Each year, as the weather turns frigid, I wonder, “How will the birds find warmth?”

The answer to this question is actually quite fascinating. Some species cope by migrating away to warmer climates; but those who stick around through the winter have many physical and behavioral adaptations to maintain body warmth. I cut the following information from About Birding. How many of these facts do you already know? Which ones are new? Which surprised you? I was surprised to learn about the scales on bird legs and feet… now I know their function!

Physical Adaptations

Feathers: Birds’ feathers provide remarkable insulation against the cold, and many bird species grow extra feathers as part of a late fall molt to give them thicker protection in the winter. The oil that coats birds’ feathers also provides insulation as well as waterproofing.

Legs and Feet: Birds’ legs and feet are covered with specialized scales that minimize heat loss. Birds can also control the temperature of their legs and feet separately from their bodies by constricting blood flow to their extremities, thereby reducing heat loss even further.

Fat Reserves: Even small birds can build up fat reserves to serve as insulation and extra energy for generating body heat. Many birds will gorge during the fall when food sources are abundant, giving them an extra fatty layer before winter arrives.

Torpor: Many birds will enter torpor to conserve energy during cold winter nights. Torpor is a state of reduced metabolism when the body temperature is lowered, therefore requiring fewer calories to maintain the proper heat. Most birds can lower their body temperature by a few degrees, but torpid birds have lowered their body temperatures by as much as 50 degrees. Torpor can be a dangerous behavior, however, as the reduced temperature also leads to reduced reactions and greater vulnerability to predators. Hummingbirds, chickadees, swifts and other types of birds regularly use torpor as a way to survive cold temperatures.

Behavioral Adaptations

Fluffing: Birds will fluff out their feathers to create air pockets for additional insulation in cold temperatures.

Tucking: It is not unusual to see a bird standing on one leg or crouched to cover both legs with its feathers to shield them from the cold. Birds can also tuck their bills into their shoulder feathers for protection.

Sunning: On sunny winter days, many birds will take advantage of solar heat by turning their backs to the sun (therefore exposing the largest surface of their bodies to the heat) and raising their feathers slightly. This allows the sun to heat the skin and feathers more efficiently. Wings may also be drooped or spread while sunning, and the tail may be spread as well.

Shivering: Birds will shiver to raise their metabolic rate and generate more body heat as a short term solution to extreme cold. While shivering does require more calories, it is an effective way to stay warm.

Roosting: Many small birds, including bluebirds, chickadees and titmice, will gather in large flocks at night and crowd together in a small, tight space to share body heat. They can roost in shrubbery or trees, and empty birdhouses and bird roost boxes are also popular locations to conserve heat. Even individual birds choose roost spots that may have residual heat from the day’s sunlight, such as close to the trunk of a tree or near any dark surface.

How many of the adaptations is the Mourning Dove using to find warmth?

Use this photo of a Mourning Dove perched in the warmth of Spring as a frame for reference.


Science behind this post:

How do Wild Birds Keep Warm in Winter? – http://birding.about.com/od/birdingbasics/a/howbirdskeepwarm.htm

Winter Bird House Plans- Keep Your Birds Cozy all Winter Long – http://www.birdwatching-bliss.com/winter-bird-house-plans.html

Roost Box for Songbirds  http://wdfw.wa.gov/living/projects/roost.html

Suet Feeders for Birds – http://wdfw.wa.gov/living/projects/suet_feeders.html

Weekly Photo Challenge: “Warmth

8 comments

  1. One piece of information — whether accurate or not — that I’ve carried in my head for years is that birds don’t suffer cold feet as much as we do because their feet have fewer nerve endings than ours. Maybe the scales are like our hair and fingernails, part of the organism minus the ouchiness factor?

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    1. Could be. I wonder if the fewer nerve endings is part of the metabolism make-up of birds… Whereby they have two systems: one that is faster to keep heat near vital organs, the other slower on to the extremities… I think that would make sense. I’m going to see if John Rakestraw, a local bird expert can weigh in on this.
      – Jane

      Liked by 1 person

  2. Amazing how the bird’s shape alters with that ‘fluffing’ up technique – and all bunkered down too keeping those tootsies warm. I didn’t know that about the heat properties of the scales on the legs and feet either. Informative post 🙂

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    1. Hello Liz-
      I agree- how often have you wondered how water birds, in particular, survive winter’s icy waters? I can’t believe I didn’t look into an answer to this question a long time ago. Pretty amazing that many species also have the ability to keep warm blood circulating near vital organs while allowing extremities to cool down.
      BTW- bird body heat is warmer than we are; generally around 106 degrees F.
      ~Jane

      Like

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