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How do Birds Stay Warm in the Winter?
January 19, 2009
It has been so cold, that I swore I saw some penguins walking down the street this past week.
Much of North America is or has been in the grip of one serious cold spell this past week.
Times are changing............
Break out the sun block and pass the iced tea, we're about to have a heat wave.
The thought of temperatures in the 20's and possibly reaching 30 degrees is enough to make a man do some stupid stuff.
We've gained close to 40 minutes of daylight since December 21st.
Now that is something to make a body jump for joy.
One official month of winter gone, two more to go (officially).
Snow keeps piling up.
Heat bills too.
Yet, we keep getting closer to spring.
One thing about this weather.............
It sure brings an abundance of birds to my feeding stations.
Saturday afternoon, I counted 15 male cardinals at the same time. The females were around too, but it is easier counting the red birds.
I managed to count 9 Black-capped chickadees at the same time as well.
I think Karen thought I was nuts getting so excited.
Do you have some time to watch your birds?
I really get a kick out of watching my birds feed and flit around.
I love birds.
I am jealous of their freedom to fly anywhere they want to go.
I enjoy the color contrast of the male cardinals and the white backdrop winter provides.
The subtle beauty of a female cardinal.
Step outside and I hear chickadees, goldfinches, woodpeckers, juncos and other sparrows.
The loud squawk of a Blue jay can be heard.
How many birds patiently wait for me to fill the feeders.
The feeder to the left needs a serious cleaning.
I enjoy watching the birds feed and that is difficult to do at a snow covered feeder.
Do you notice how chickadees will snatch and run?
Watch chickadees and you will observe them selecting just the right seed (by weight) and take off to a protected area to pick it open.
Chickadees need to find a seed worthy of their effort so the actually weigh them.
They need a lot of energy and no time to waste on sunflower seed with a small meat inside.
Nuthatches will grab and place the seed or peanut meat in a crevice and peck away.
Jays seem to swallow whole.
These birds will also stash or Cache seeds in hiding spots for emergency feedings.
Studies have shown that these birds can recall hiding spots for at least 30 days.
I like to watch other birds like cardinals and finches work a seed from the hull.
How they maneuver the seed around, get the goods drop the empty hull and grab another seed.
Another thing you can observe this time of year is the pecking order of your bird population.
Yes, in many species of birds there is a hierarchy.
There is often an Alpha male.
For Northern cardinals, it is easy to pick him out.
The most colorful or brightest red bird is the boss and gets first feeding rights, followed by his lady.
He also gets the choicest breeding grounds.
For other species, it is more subtle, but easy to pick him out be watching for a few minutes.
Sometimes it is the elder statesman, or it could be the most aggressive male.
The thing is, you can watch and learn who's the boss.
After that, there is the Beta and down the line, much like the pecking order in a wolf pack.
If you have some time, sit down and watch your feathered friends.
Sometimes it is an act of aggression, or even a subtle body posturing.
You may even observe other birds sitting back and waiting their turns.
This time of year, birds will show up in loose flocks or small groups.
In that group is a dominate male.
I have several feeders and sometimes, I think just to assert his bossiness, the Alpha will chase others away.
When this happens, several birds of a feather will move to the front yard feeders and visa versa.
Other times, everyone eats in harmony.
It is a wonderful scene to see your feeders and yard full of birds.
Helping birds in the winter is becoming more important with the decline of habitat.
Helping wildlife not only helps them, but helps you as well.
You can't help but feel good about yourself when you help out some one else, or in this case, helping wildlife.
Now here are some important ways that "Nature" helps birds to stay wram during the cold winter.
You may know, I like to take evening walks.
Often the dogs will join me, but this sub zero stuff makes it to cold for my four footed family members.
Not to mention the snow is to much for the little pooches to walk through.
Winter poses several challenges for our birds as well, especially when the temperatures dip and dip some more.
We don't often think about or wonder how our birds survive the colds nights, we just know they do or at least we hope they do.
Even those moments in the deep South, Desert regions or the Pacific coast where a cold snap or several inches or feet of snow fall, can effect a bird population.
Winter brings extreme cold temperature, strong winds, driving snow and rain.
Nights seem to last forever.
16 hours of darkness and in some locations more fall on the land.
That doesn't leave a whole lot of time to forage and feed.
Yet, many birds must at least triple their normal intake to survive and do it in half the time.
Each winter we lose many of our feathered friends to the rigors of winter.
It's how "Nature" works.
Survival of the fittest.
Passing on the strongest genes.
Birds have many adaptations to survive the extremes of winter.
Some birds migrate.
Some adjust their diet habits.
Birds such as chickadees and American goldfinchs add feathers in preperatoin for winter.
Yes, the typical chickadee or goldfinch is covered with about 1,000 feathers during the summer.
By the time winter arrives, they have doubled that count to more than 2,000 feathers.
For a small bird, that can be some serious added bulk and weight.
During cold, windy or just a plain nasty day, birds will fluff up their feathers.
By doing this, they create dead air pockets, much like insulation or a double pain window.
This reduces the heat loss by up to 30%.
Extra feathers and fluffing isn't enough to make it through a cold winter day yet alone the cold, long dark nights.
If you've been with me any length of time, you have read about blood circulation and bird legs.
Birds have a unique circulatory system in there legs to help them cope with cold temperatures.
Pay attention to this now.
Warm arterial blood from the birds interior, which is on its way to the bird's legs and feet, passes through a network of small passages that runs alongside the cold returning blood veins from the feet.
The network of vessels acts like a radiator and exchanges the heat from the out-going warm arterial blood to the cold venous blood.
By warming up the old blood, no heat is lost and the feet receive a constant supply of life sustaining blood.
This is also why water fowl can swim in near freezing water and not get cold.
In the summer, this works as a bit of an air conditioner.
A Side Note:
Because the blood doesn't warm up a bird's feet and because of the scales (no skin, no sweat) birds don't freeze to metal poles or birdbaths.
Fat is another important winter weather survival adaption.
Fat acts as an insulator in addition to an energy reserve.
During the day, birds eat to build up fat reserves.
On average, a bird can put on up to 15% to 20% of body weight in fat before it becomes to heavy to fly.
Now remember, days are shorter and cold.
Birds have to eat enough to survive the day as well as replenish the fat reserves.
The smaller he bird, the higher the metabolism (more energy burned).
Birds don't have brown fat, the kind we have.
Instead they have white fat.
White fat is a high-energy fuel used to power the bird's warming process.
Thermogenesis is a fancy name for shivering.
You can't really see it, but all birds shiver in the cold of winter.
From the largest of birds like eagles and water fowl to the smallest of birds like hummingbirds.
They all shiver to maintain their core body temperature at about 106 to 109 degrees, depending on the species.
That is an amazing high temperature compared to the surrounding air temperatures.
This past week in some locations, that is more than a 150 degree difference.
Shivering produces heat five times their normal basel rate and can maintain a normal body temperature for six to eight hours at temperatures dropping to minus 70 degrees Fahrenheit.
Without shivering the bird's body temperature would quickly drop and the bird would become hypothermic.
I might add this, penguins only shiver if a patch of skin is showing, or there is some feather damage. Penguins are a different sort.
At night, birds such as the little chickadee take shivering, or lack of one step further.
To conserve heat and energy, chickadees can lower their body temperature by interrupting their shivering.
These periods of inactivity allow the bird's body temperature to slowly cool, until it drops about 10 or 12 degrees.
At this point, the bird enters a state of unconsciousness called torpor.
Respiration and heart rate will also drop during this period.
As morning nears, the periods of inactivity decrease until the bird is constantly shivering once again.
The body temperature is back in the normal range and the bird regains consciousness.
The results of this torpid state is an energy savings of up to 20% during a typical winter night. (much like you and me turning the thermostat down before we go to bed).
Conserving energy is very important when you consider how little fat a bird can store.
Based on a daily increase of body fat of 15% a typical chickadee has about 16 to 24 hours of fat or energy reserves to carry it through a winter night.
That my friend is why it is imperative that a bird gets out early in the morning and stays out late to find food regardless of the weather.
If it doesn't replenish its fat reserves every day, the bird will not have enough energy to make it through the next night and will die.
There was a time when the natural world provided food for most wildlife.
With the constant shrinking of habitat, winter protection and food supplies continue to shrink.
You can increase the odds for birds and some mammals by simply filling your feeders with their favorite food and offering suet.
Fresh water is important as well.
When birds are required to eat icy cold snow, it takes valuable energy to warm that snow as it passes through.
Next time you trudge out into the cold or even the warmth to fill your feeders, think of this...............
God has provided birds with some wonderful tools to survive, whether it is migration, blood circulation, change of diet, added feathers, or shivering.
Birds are truly a wonder for us to enjoy.
In one way, it is unfortunate that many birds now need our help to survive.
Yet look at the education and joy we get out of caring and feeding our birds.
Not to mention that feel good all over feeling we get.
Well, it's time to fly for now.
Before I go, here is your positive thought for the week.
Laughter is the sun that drives winter from the human face.
What better way to end a letter after a very cold winter week.
Laughter is good medicine, it melts the cold winter looks from our face.
You know the look...........
Laughter can heal and brings a light to your face which adds a glow to any room you are in.
Laughter is contagious,
Laughter wipes the frowns off a face, adds a twinkle to the eyes and a glow to the cheeks.
Now all that laughter puts a smile on your face that carries over.
Smiles rub off onto others and on to others etc.
It may be cold and gloomy outside, but your smiles and laughter cheer up and warm up the dark and gloom of winter.
Go out there and add some warmth by sharing a smile and a chuckle or two.
Smiles don't cost a thing, yet can add such value to another person's life.
Do you think if we all laughed and smiled, we could chase away the real winter?
Well, it was a nice thought wasn't it?
Until next time my friend.
Be sure to laugh and show your pearly whites.
"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,
PS. If you enjoy these letters, please forward them to friends, family and co-workers. Better yet, have them sign up so they can recieve their own letters.
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