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The Incredable Bird Eggwhat's in it, how's it made
May 04, 2009
My apologies if graphics aren't lined up today. I try to line them right and left, but for some reason something is off whack for now.
Thank you for your patience.
May is here.
May is my all time favorite month and time of the year.
Temperatures finally begin to moderate and the world turns green with many shades of reds, pinks, yellows, whites and blues.
Here is southwest Michigan, May is also planting season.
Gardeners in the north country have been chomping at the bit all year, waiting to get our hands dirty and to plant whatever we can get our hands on.
Though we understand that growing season may start in March or earlier for many of you, us northern folk look to May as an almost religious experience.
Hopefully the dangers of killing frost will be over soon.
We can't wait.
May brings Magnolia and then dogwood to bloom.
Forsythia and Quince are flowering.
Fruit trees are beginning to flowers as well.
Later this week and next week, Columbines will begin in flower and I can expect hummers for sure.
So many other flowers and plant life to look forward to.
Yes, the month of May is my time of year.
May (the last couple days of April) also brings ......................
Besides the regulars,
I now have a yard full of White-crowned sparrows that will stay for a couple more weeks.
A Brown thrasher has blessed me the past few days as he scratches under the shrubs and flower beds (save some leaf litter).
Walks near the woods bless me with a variety of song, including several Gray catbirds.
Killdeer are running around and Tree swallows fill the air with their graceful, acrobatic flight.
For a short while, I will be blessed with a handful of Rose-breasted grosbeaks.
Usually we have 1 or 2 males, but right now we have a handful of males.
It wont last, they rarely stick around, but for now.......................
Grosbeaks sound a lot like robins, but smoother and richer.
Think of a robin as Kenny Rogers singing.
Now compare that of a grosbeak as Julio Iglesias.
Now that is singing.
Both can sing, but one is much richer than the other.
May brings baby birds and fledglings.
Still no orioles or hummers in my yard, but I understand they've been spotted in parts of Michigan.
A mother rabbit was busy building a nest in the neighbor's yard (right in the middle of the lawn) this past week, I'll be curious to see what comes of it.
May used to bring something else when I was a child.
Do you remember May Day?
It was something special for children everywhere.
Making a basket and picking flowers to give to your mom or grandma.
Sometimes the basket was full of dandelions and violets, but mom (grandma) didn't seem to mind one bit.
What ever happened to "May Day"?
Say, I recently planted a couple more native grasses to my landscape and it got me to thinking.
If you have planted or plan on planting anything new, different or extra to attract wildlife, we want to hear about it.
Maybe you plan on working your landscape to attract more wildlife (growing or shrinking).
It is time for reader participation once again (always popular and I like that).
Most of us plant or add something to attract hummers or other birds, but it could be planting to attract butterflies and caterpillars (nectar and host plants)
Maybe you want toads, dragonflies, bees or other wildlife life.
What are you doing or want to do to attract some of god's critters?
Adding a small pond or another birdbath?
Offering a cool moist spot for toads or salamanders?
Sprinkling wildflower seeds or trading for plants.
Planting another native shrub or tree?
Shrinking lawn area into wildlife area?
It could be adding another container to your deck or porch or dressing up a window box.
Come on everyone...........................................
Let's share your plans and ideas.
Let's make this a fun time as we can discover what others do from around most of North America.
Old timers you know the drill, but this is for all the rookies.
Your first name,
City or town you live in or near
Your state or province.
A nice sentence, paragraph or two.
Whatever it take to explain what you are doing or plan on doing this year.
In a couple of weeks, you will be published and get your few seconds of fame :-)
Let's have a good turn out gang.
Maybe so much so it will span more than one letter (that would be fun).
The first of a month also brings maintenance.
Be sure to deep clean all your feeders and water sources.
As the weather heats up, it is more important to keep things clean on a regular basis and more often.
Continue feeding the birds if you can.
Sometimes nesting moms need the extra "oomph" our feeders can offer.
Not to mention, parents often bring offspring to your yards and feeders later on.
By gardening for birds and wildlife and supplementing food sources, you can attract and almost plan on having certain visitors.
This might be a good time to slide out, or into this week's topic.
Last week, I discussed a bit on "bird love" and eggs.
Today, I'm going into more detail on bird eggs.
How they are made, what's in an egg and more.
Here is a tidbit for you.......
Oology is the branch of ornithology that deals with the anatomy and physiology of eggs as well as the size, shape, color and other characteristics.
Don't you feel smarter already :-)
After mating, inside the female, sperm may wait several weeks or swim up a tube called the oviduct, at the end of which there is an ovum.
If the ovum is mature, it's already equipped with yolk, the yellow part of the future egg.
The sperm may now fertilize the ovum by penetrating it and uniting the two reproductive-cells' genetic material.
Fertilization doesn't necessarily take place soon after mating; domestic chickens and turkeys can produce fertile eggs seventy days after copulation.
After fertilization, the ovum with its yolk begins its own journey down the oviduct, a process lasting about 24 hours.
During the first three or four hours, moving along the way, the albumen (egg white) is added around the ovum and its yolk.
(The picture above is a bird ovary and you can see the different stages of the yolk and ovum as it devlopes.)
The yolk will serve as food material for the developing chick; the white will mainly keep the yolk from drying out, and will give the yolk physical support.
A side bar:
(The yolk size varies from bird to bird. The more independant the hatchling is, the larger the yolk will be.
Geese, ducks and chickens have a larger yoke per egg size than birds hatched helpless.)
Now the future egg slows to about 40 percent of its earlier speed, and membranes are added around the yolk and egg white.
Finally the shell is put in place, taking 19 to 20 hours
The egg them moves to the uterus, or shell gland, where the calcareous shell is added and, in some birds, pigment is added in characteristic patterns.
The shell is mostly composed of the mineral called calcium carbonate, which has the same chemical formula as limestone.
(No wonder egg shells are so hard and brittle.)
Pretty amazing that all of this is built up around the yolk in a 24 hour period.
The egg then passes into the vagina and cloaca for laying.
I would call that one effeciant assembly line.
Technically speaking, eggs are single cells, even though we normally think of cells as too small to see with our naked eyes.
In fact, eggs are the largest cells known in the animal kingdom.
They range in size from tiny ones produced by hummingbirds (0.006 oz, or 0.2 gram), to nearly 20LBs (9 kg), laid by the Elephantbird of Madagascar, which is now extinct, but was known by primitive humans.
The Components Of An Egg.
An egg has four basic structures: the yolk and its associated membranes, the germinal disc, the albumen (white), and the shell and its associated membranes.
Each component performs specific functions in the development of the embryo.
The yolk is the main source of nutrition for the embryo.
The fat gives yolk its yellow color. The more fat contained in the yolk, the darker the yellow.
Surrounding the yolk are four membranes that keep it intact and in contact with, but separate from, the albumen.
After the egg has been fertilized and incubation starts, a system of blood vessels develops within these yolk membranes, which completely surround the yolk and carry nutrition to the embryo.
On the surface of the yolk is the germinal disc, a small disc of cytoplasm containing the DNA nucleus of the female cell, or ova.
You need a microscope to see the nucleus, but you can see the germinal disc with the naked eye.
It appears on the surface of the yolk as a white dot.
“If the egg is fertile, the dot is called a blastoderm; if it is not fertile, it is called a blastodisc.” The blastoderm contains the genetic material necessary to develop into offspring of the parent birds.
The albumen is the white or clear part of the egg that surrounds the yolk.
Made up mostly of protein, it also contains globulins, which provide immunity from disease.
The albumen feeds the developing embryo with water and protein. When the chick is ready to hatch, the albumen acts as a lubricant to help the chick turn, push and struggle to free itself from the egg.
Albumen consists of thick viscous forms and thin, watery forms.
A layer of watery albumen surrounds the yolk, and a more viscous layer of albumen is in contact with the watery layer.
A third watery layer of albumen is in contact with the shell’s inner membrane.
A dense layer of albumen called the chalaziferous layer is in direct contact with the outer yolk membrane.
An extension of this layer forms the chalazae, twisted strands of thick albumen that connect to the shell membrane at each end of the egg.
The chalazae stabilizes the yolk and embryo in the center of the egg within the albumen layers.
The chalazae is much like a shock absorber that keeps the yolk and embryo stable.
The chalazae become twisted as the egg is turned during incubation.
These invisable strands are what make it difficult to seperate the white from the yolk when recipes call for whites or yolks.
The hard outer surface of a bird egg is the shell.
It provides protection and structure to house the embryo.
The shell contains pores to allow for transpiration of water through the shell.
The shell consists of three layers; the outermost layer is the cuticle.
Beneath the cuticle is the calcium carbonate layer called the testa, and the innermost layer is the mammillary layer.
The cuticle consists of dried mucus laid down by the uterus and serves to regulate evaporation of moisture and to protect the embryo from bacterial infection.
The testa is the layer that makes up most of the eggshell structure and provides calcium to the growing chick.
It is also the layer that contains the pigments if the egg is colored.
The mammillary layer is in direct contact with the shell membranes and is the foundation for the testa.
Two membranes lie directly beneath the shell: the inner shell membrane and the outer shell membrane
At the blunt end of the egg, the two membranes separate, forming a space between them called the air cell.
The air cell is formed after the egg is laid and cools.
The outer shell membrane adheres to the mammillary layer of the shell. The inner shell membrane covers the liquid inside the egg.”
"Nature" has made it possible for birds to lay from a single egg to 20 or mare and have them sit dormant for a period of time until incubation begins.
This way all the eggs can hatch within hours of each other.
Some birds do lay and hatch on an every other day schedule, however.
Well, I think that is a good start on what makes up a bird's egg and how it is made.
A pretty special process don't you think?
Next week incubation and more.
Remember to email me your "Gardening For wildlife" add ons and plans.
Simply forward to this address.
Before I go, here is your thought for the week.
"Worry and fear cannot live in the same space with hope and action. When you stand on faith and take positive action, you evict worry and fear."
Just like that, another positive action thought.
(Where were these people and that thinking when I was growing up?)
A thought that has you choosing which way to go.
What is interesting, is you cannot willingly and knowingly have a positive and negative working your brain and body at the same time.
Fear is a powerful emotion, but it gives way to positive when "we" make the choices.
Yes, sometimes we need the help of friends, but you ultimately make the choices.
You can attend all the self help seminars out there, but until "YOU" make the choice and "YOU" decide what path you will follow, you're wasting your time and money.
Read it again............................
Worry and fear cannot live where hope and action are.
Have faith and take action.
It may be saying no to someone or something.
It may be taking that first step toward freedom or really following your dreams.
For decades we have lived in comfort zones (like them or not). Now it is time to take a baby step out and move forward.
Take action and watch the fears and doubts melt away.
Step out in faith (prayer always helps).
I believe in you,
You must believe in you.
Make the right choice and become the person God always had planned for you.
Now that has got to put a smile on your face.
Now be sure to share your smile with others and more important, with a stranger or two.
See, smiles are a positive choice and you wipe away your frowns.
Smiles are so easy to do, yet have such a profound effect of the both the giver and the recepient.
A baby step (by choice).
Now go get em
God's many blessings.
Until next times,
"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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