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Turtle Hibernation, A Few Facts
November 04, 2013
Here is the picture from last week on the two trees that were just starting to change colors (behind this year).
Below are a couple of pictures taken of the same trees.
One picture is on Wednesday, and the other picture was taken This past Sunday.
It was a quick change and cool to watch the transformation from day to day.
Now come the adjusting to my days becoming an hour shorter (night side).
Every year it is a challenge, but I do enjoy 'Daylight Savings Time'.
We turn the page on the calendar to November.
The last couple quarts of tomatoes have been put up.
The only thing left is some leaf lettuce and a few beets.
Still no killing frost in my yard.
With some sadness, I must finish putting gardens and flower beds to sleep for the winter.
That means yanking and cutting plants that are still showing some flowers.
It really is too cool for plants to grow.
I'll leave a Red Salvia or two just to see how long it lasts.
(Sunflower volunteer spouting in the tree out front, doesn't take much does it?)
A new month also means it is time once again to clean your feeders good.
Especially before the snow and cold gets here.
If you don't have the time or means to give your feeders a good scrubbing, use this little trick.
Spray them down good with rubbing alcohol.
While this wont clean off girt and debris,
Alcohol kills of any cooties and germs.
It dries or evaporates quickly, leaving no harmful residue to hurt your birds.
It always works in a pinch.
If you haven't check your water heaters and get new ones if needed.
A birdbath that is frozen solid doesn't do the birds much good, and quite possibly your water source may crack from the expanding ice.
(Berry tree in field.)
We were blessed with a sunny day with mild temperatures (mid week).
I took advantage, as the rest of the week was going to be rain, rain, and more rain.
Toss in some wind and cooler temperatures.
The walk in the field and woods did me some good.
I was followed by a handful of Black-capped chickadees (i love these birds).
Along woods edge and scattered about the field are several wild crabapple trees and other berry producers.
Cedar waxwings I always hear first.
Of course they move around to much to get pictures, but there was a nice flock of them gorging.
Waxwings are a nomadic bird that fly around to find the fruits.
Here today, gone today type of birds.
I kid you not, scores upon scores of robins.
About the only way i was going to capture a robin, was to zoom in on a fruit tree, snap and look.
What do you know,
A robin enjoying a meal.
I've mentioned this before.................
American robins are in no big hurry to migrate (some spend the winter).
As long as there is food, many robins will stay and fatten up.
Fruits and worms are still plentiful in my part of Michigan, and the robins are testament to that.
While some robins may take a long journey south, many will migrate only as far as they have to.
And only when it is required.
I had another pleasant surprise on my walk.
I came across not one, but two 'Box turtles' taking in the sun one last time, and possibly looking for a last meal.
This caught me a bit off guard.
I've never seen Box turtles in the fields before, let alone in late October.
I figured turtles to be hibernating by now.
They were sluggish for sure, but very much awake.
Right in the walking path where they could enjoy the warmth of the sun (15-20 yards from the creek).
Most of you know that turtles hibernate under water.
Like me, I'm sure you didn't know the whole process a turtle goes through to manage this journey.
So I did some digging in hopes to offer you some answers.
I keep saying this, but the Natural world never seizes to amaze me.
Hibernation is for animals that cannot make a living during the winter.
It's a great way to avoid the problems of cold and unavailability of food.
The process seems to be quite simple.
Store up lots of fall fat reserves and when things get unbearable, lower the metabolic rate and sleep through the bad weather.
Enter a torpid state.
This takes a lot less energy than trying to relocate buried acorns under several inches of snow, or to migrate hundreds, or even thousands of miles.
Though the principle of hibernation may be simple, the execution of the process is complex.
With a bit of digging and research, this is how it works. Water is capable of absorbing and storing tremendous amounts of heat with only a slight increase in temperature.
It cools off just as slowly as it warms up, meaning that aquatic life undergoes relatively moderate fluctuations in temperature.
Another quirk of water is that at 39 degrees Fahrenheit water achieves its greatest density and sinks to the bottom of ponds.
At all other temperatures, both warmer and colder, water rises.
This unique micro-climate is quite comfortable for turtles and other creatures hibernating at the bottom of ponds.
Check this out.........
If the water becomes cooler than 39 degrees, the cooler water rises.
Thus the turtle can never become frozen.
When the bottom finally begins to warm in spring, the change sets off a biological alarm clock in the turtle, and it awakens.
But, the property of water that keeps the coldest layers above the bottom of the pond could be deadly to an air-breathing creature like the turtle.
At 32 degrees (0 C.) water expands and freezes, leaving an impenetrable self-sealing layer of ice between the pond's surface and the hibernating creatures trying to get a good winter's nap.
In more northern latitudes ice may persist for up to four months.
That's a long time to hold a breath for even a turtle to hold its breath.
How do turtles get enough oxygen to survive their winter's nap?
This is another way that Creation in all its wisdom comes into play once more.
For one thing, their 39-degree blanket at the bottom of ponds has remarkable benefits for oxygen use.
If the water were warmer, the turtles would use more oxygen; colder, and their cells, being made primarily of water, would freeze.
Jagged ice crystals rupture cell walls from within, and if enough cells were broken the turtle would die.
So a hibernating turtle is sleeping in a snug zone of perfect temperature for its temperamental cells.
Yet, with its submerged lungs unable to breathe, the turtle still faces slow oxygen starvation and a lethal buildup of carbon dioxide.
Turtles and other reptiles, however, have skin clothed with thick scales and, of course, a major portion of the turtle's body is covered with a shell.
Absorbing oxygen through the skin is no more an option than flying south.
Aquatic turtles, like the Box turtle, have two sources of oxygen to satisfy their winter needs.
One is their throat cavity, which is lined with lots of minute blood vessels that permit oxygen to be extracted from the water.
The second is a similar type of tissue present in two thin walled sacs near the anus.
A small amount of food coloring placed near a captive turtle sleeping on the bottom of an aquarium will show faint independent pumping movements of water at each end of the turtle.
To demonstrate the turtle's effectiveness at breathing through its anus and its pharynx, researchers submerged captive turtles for up to eight days.
All the turtles survived.
Cold water traps and holds more dissolved oxygen than warm water, thus assuring that additional oxygen is available under ponds.
While these capabilities augment oxygen, they do not, by themselves, get a hibernating turtle through an entire winter.
Perhaps the threat of slow oxygen starvation in wintering turtles can be explained by the example of a long-distance runner.
Runners who push themselves to their limits often experience the consequences of muscle cells trying to perform on insufficient oxygen.
Normally, muscle tissues are fueled by oxygen-burned carbohydrates.
But as the system is stressed, runners experience shortness of breath because it is difficult to take in enough oxygen.
The hibernating turtle, however, can get away with oxygen deprivation for much longer periods because its metabolism is lower than mammals.
Turtles don't do much and live for relatively long times.
Their metabolic rates are normally 10 times lower than those of warm-blooded animals of similar size.
In hibernation this drops by 10 to 20 percent of the normal tranquil rate.
Turtle hearts that beat 40 times a minute on a warm day in July drop to one beat every 10 minutes in the winter.
So it's simple enough, after all.
A turtle's anaerobic metabolism gets it through the winter.
Not so fast my friend.
There is still a buildup of lactic acid to deal with for the months the turtle is sealed under the ice.
Naturally, the turtle slows the buildup by doing next to nothing throughout the winter, but its body functions still produce enough toxin to kill it before winter runs its course.
Again, the solution is quite simple.
Minute amounts of calcium salts from the turtle's shell are slowly dissolved into its bloodstream.
These salts act as a buffering agent, neutralizing the lactic acid.
Researchers at Brown University in Rhode Island.
Using enough sophisticated equipment to intimidate a rocket scientist, researchers have been tracking the internal chemical balances of turtles for some time.
In tracing the calcium, they discovered these salts perform another invaluable service.
Acidosis can depress the heart rate so much that it stops, but the calcium keeps the pump on schedule.
One day, these studies may have implications for enhancing knowledge of clinical problems of more interest to us, but for the moment the researchers are simply trying to understand turtles.
Meanwhile, under the ice, and above it, the life of gray winter days goes on, with each plant and animal using its own God Given mechanisms to survive.
Soon, the days grow longer.
Water in its solid state melts, and sometime in March or April the turtles once again poke their noses into the air, filling their lungs with oxygen.
While they can neither sigh nor smile, the first breath of spring must be an emotional moment, even for a sleepy turtle.
Then, as the first sunny days arrive, the turtles will haul themselves out on a log or rock, to bask and raise their body temperatures above that of the water.
I don't know about you, but every time I learn a bit more, I am even more amazed at the gifts that surround us.
Nature is indeed a gift from the All mighty.
Well,, it is time to fly for now.
Before I go, here is your positive thought for the week.
Rely on the ordinary virtues that intelligent, balanced human beings have relied on for centuries: common sense, thrift, realistic expectations, patience, and perseverance.
John C. Bogle (1929-) American Investor
Here is one of many passages in the Bible on virtues.
"Finally, brothers, whatever is true, whatever is honorable, whatever is just,
"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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