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How Do Birds Stay Warm In Winter
January 09, 2017
A belated Happy New Year.
By having nothing on the schedule for these past two weeks has done wonders for us around here.
We try to make sure not to schedule any appointments.
I chose a few years back not to write a newsletter as well for this time frame.
This allows our household to slow down some, to relax and enjoy the Christmas and New Year season.
To remember the reason for the season as well.
Pictured is Snicker Doodles sporting a new lavender colored harness, while beating up a new toy.
Hey, the fur kids are part of the family too.
At the bottom of letter you will see Miss Penny resting between Yolanda's legs.
Before the Arctic blast this past week, we had a New Years warm up.
All the snow had melted and a chipmunk decided it was time to restock its lair.
Chippies don't really hibernate, as we think of hibernation.
They do go into long sleeps, wake up from time to time to feed, and like this critter, decided it was time to restock the groceries.
I guess with a steady food supply there is no need to hunker down for now.
Even on the single digit days, and snow cover, Chippy is still busy all day long.
Another treat to break up the winter doldrums.
Pictured below are some winter robins feeding on Winterberries.
Notice the partial albino robin in the mix.
I'm not sure, but I think he is the same one that was a visitor all spring and much of the summer.
The chicken wire is to keep the deer from chewing the young bushes down.
Are you ever amazed at the wide variety of winter birds that visit their feeders even on the coldest and stormy days?
And the great numbers of a certain species?
Days like this past week will bring a couple of dozen Northern cardinals.
Numbers I otherwise don't see.
Why don't these birds fly south?
Do you stop and wonder “how do wild birds keep warm in winter?”
Creation has given birds many superb tools that allow them to survive even in the most frigid conditions.
Once you understand what birds need to keep warm can easily help their feathered friends.
Bird Body Temperatures:
Birds are warm-blooded animals that have a much higher metabolism, and thus higher body temperature, than you and me.
While the exact temperature varies for different bird species, the average bird’s body temperature is 105 degrees Fahrenheit (40 degrees Celsius).
Body temperature can fluctuate during the day depending on climate and activity, but it can be a challenge for birds to maintain such a high body heat when temperatures dip too severely.
Smaller birds are particularly at risk, since they have a proportionally larger surface area on their bodies to lose heat but a smaller core volume to generate it.
Even the smallest birds, however, have several ways they can efficiently keep warm.
What Birds Do to Keep Warm:
Birds have many physical and behavioral adaptations to keep warm, no matter what the low temperatures of their surroundings.
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.
Including extra down feathers.
American goldfinches for example can grow up to 50 percent more feathers for the winter months.
The oil that coats birds’ feathers from their uropygial gland 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.
These specialized scales also prevent moisture from freezing to the legs and feet, so birds wont stick to a birdbath or mettle perches.
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.
Birds also feast from sunup to sundown to build up a fat reserve to help survive the long and colder nights.
For little birds like chickadees, this is always a challenge, as they pick a seed, fly off and eat it
Chickadees will do this all day, spending more energy in the process.
Watch a Jay, and they will sit and swallow things whole all in one sitting when possible.
Big difference in efficiency.
Fluffing: Birds will fluff out their feathers to create air pockets for additional insulation in cold temperatures.
This can make them look fat and puffy while they are toasty warm.
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 and to breathe air warmed from their body heat.
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 in extreme conditions.
Sunning:While rare in Michigan this time of year, we will open the door and allow the sun's rays to help warm the house.
As soon as the door is open, you will find our fur kids parked right in the sunny warmth.
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.
You can almost imagine how good this must feel to them.
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 bird houses 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.
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 dangerous, however, as the reduced temperature also leads to slower reactions and greater vulnerability to predators.
Besides hummingbirds, chickadees, swifts and other types of birds regularly use torpor as a way to survive cold temperatures.
Helping Keep Birds Warm:
Even with all of Nature's adaptations to conserve heat and stay warm, many birds still succumb to frigid temperatures and bird mortality can be very high during severe winters.
The first to succumb are the weak and sick.
You can help your backyard flocks have an edge over the cruelest weather.
Offer Good Food: Choosing the best winter bird foods to offer means selecting seeds, suet, nuts, peanut butter, scraps and other items high in fat and calories and proteins to give birds plenty of energy to generate sufficient body heat.
Keep Feeders Full: After a long, cold night birds will need ready access to food to replenish their energy reserves.
Keep your bird feeders full of nutritious seed no matter what the weather so the birds know where to go for a high energy meal.
When possible, place feeders close to where you can care for them and enjoy the birds.
Close to protection and keep the clean.
Shovel and area or pack down snow to assist the ground feeders.
Offer Liquid Water: Birds can melt snow to drink if necessary, but doing so will use precious energy that is needed to maintain body heat.
If the birds can drink from a heated bird bath even in freezing temperatures, they will have a much better chance at survival.
Provide Shelter:Plant evergreen shrubs and coniferous trees that will provide suitable shelter throughout the winter, or build a brush pile to give birds a safe, sheltered place to roost.
Adding a roost box to your yard is also helpful.
When temperatures start to dip, it isn’t necessary to worry about how birds keep warm; they have plenty of efficient adaptations to survive even the chilliest nights.
Birders who understand those adaptations and help birds with even better food, shelter and other necessities, however, will be sure to enjoy warm and healthy backyard birds no matter how cold it is outside.
A Side Note: Research shows that wild birds on average get 25% of their food from our feeders, the rest is from what God provides.
Your birds wont all starve off, but you are lending a helping hand.
Besides, entertainment value alone is worth the time and effort spent on feeding your backyard friends.
That puts it in a nutshell.
Well, it is time to fly for now.
Before I go, here is your positive thought for the week.
The mediocre teacher tells. The good teacher explains. The superior teacher demonstrates. The great teacher inspires.
William Arthur Ward
Learn from The Teacher, seek as the Psalmist did.
Teach me your way, O LORD, and I will walk in your truth; give me an undivided heart, that I may fear your name.
"Treat the earth well:
It was not given to you by your parents,
It was loaned to you by your children.
We do not inherit the Earth from our
Ancestors, we borrow it from our Children."
Ancient Indian Proverb.
Your friend indeed,
Better yet, have them sign up so they can receive their own letters.
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