Hmmmm---I Wonder

How many "hmmm--I wonder" thoughts do you have over a months time?  Do you take time to do some research for the answer or do you continue to wonder?

I finally took the time to do some research (edu sites only) on my burning question.  Are chicken eggshells valuable to the birds in my backyard?

My grandsons have always been involved in chores during their once a year summer visit.  Not always willingly I'll admit.  The dangling carrot was if you want to go to Tumalo State Park we need to do X-Y-or Z first.  The chores were always age appropriate.  The youngest was assigned to crushing the accumulated supply of eggshells using the mortar and pestle, then adding to the compost bin.

At some point, the youngest outgrew the assignment and the process was discontinued.  The shells were never ground fine enough to decompose in our soil.  I am still seeing bits and pieces from 10 years ago and wonder by whose hand were they crushed.

When I did take time to find some answers I learned that eggshells can provide the extra element of calcium in the diet of birds, especially for producing eggs.  The diet of a particular species of bird may play a role in determining whether the species will seek supplemental calcium.  An example I read in one of the fact sheets is that  insects are low in calcium.  Birds such as swallows that eat primarily insects probably need to find additional sources of calcium.   In addition crushed eggshells also provides the grit that helps birds digest  their food.

Researchers in Europe observed birds incubating empty nests or eggs with defective shells, which led them to question whether these birds had sufficient calcium in their bodies to produce viable eggs.

The researchers found if they provided calcium to birds, they would produce defective eggshells less frequently and their rate of hatching failure would decrease.  A possible theory was that the birds were unable to find the calcium they needed in the environment, possibly due to acid rain at that time which leached calcium and other elements from the soil.

If you want to save eggshells as a backyard provider of calcium for birds there is a process.

The shells should be rinsed.  Dry in an oven or in a microwave.  Shells should be crushed after drying.  Apparently the size of the crushed shells should vary.

 The oven temperature would be 250 degrees F for about 10 minutes.  The shells need to be dry but if left too long will turn brown and will be distasteful to the birds.

The time for a microwave was listed between 1.5 - 3 minutes, probably best to go in 30 second increments.

Parent birds remove the shells from the nest after hatching to keep the nest area clean.  They will drop the shells some distance from the nest site to confuse predators.  Now I know why I would find robin shells on the opposite side of the house from the nest.

Don't give up on the eggshells as a compost pile ingredient or as a soil additive.

Eggshells are comprised of 93% calcium carbonate and 1% nitrogen along with other nutrients.  Crush to a fine powder in a blender.  You probably don't need the lesson of patience and hand dexterity!