Easter means eggs for Lowcountry birds that are producing, laying and warming a future generation today. Miraculous new life will emerge from what look like inert lumps of chalk or porcelain. A feathered female begins forming her first egg several days before she releases it, perhaps while she and her mate are still building their nest. The mother bird draws about 40 percent of the shell calcium from her bones. She also searches for calcium-rich foods and may eat the shells from her first batch of offspring.
People sometimes help by putting clean eggshells, left from breakfast, under a bird feeder.
The eggs of many songbirds such as cardinals and mockingbirds contain 20 percent to 25 percent yolk, the fertilized egg and nourishment for the growing embryo that will hatch as a featherless, helpless chick with eyes still closed. Yolks make up 40 percent to 50 percent of the egg for birds such as ducks and turkeys, whose young develop further in the egg and emerge covered in down and ready to follow their mother. A small bird like a Carolina wren produces an egg weighing about 13 percent of her weight while an ostrich egg weighs less than 2 percent. The Eastern bluebird, great egret, wood thrush and robin have handsome blue eggs, the mockingbird bluish-green. Cavity-nesting birds such as woodpeckers and chickadees usually lay white eggs that show up in the relative dark.