Sanitizing Eggshells for Bird Feeding

Raising a family, as any parent knows, is a real challenge physically. For birds this is especially true because they must dedicate weeks to laying and then brooding eggs before the family even begins. This is a big drain as the brooding parent has little time to feed and the other parent often must provide for both of them. In addition, female birds are really on a calcium deficit during egg-laying. They must produce enough calcium each day to form the shell of an egg. Sometimes it can be a problem getting sufficient calcium to produce eggs and stay healthy. We can help them by providing calcium alongside our bird feeders.


The easiest way to provide calcium is by putting out crushed eggshells. These act as grit as well, aiding in digestion. However, eggshells sometimes contain bacteria that can be harmful or fatal to the birds. To prevent this, we need to sterilize the shells so that they get the calcium but not the bonus “bugs”.


It is really simple to sterilize eggshells. First remove the inner and outer membranes. I find that it is easiest to crack off a small piece of shell to the inside of the shell. If you are careful, this will pull the membrane away from the inside of the shell and you can work it off in one piece.


it is pretty easy to strip the membrane from the inside of the shell.

Next, rinse the shells well. Then place them in a cake pan in the oven at 250 degrees F. In twenty minutes, they are done. In this state they are very dry and can be crushed into very small pieces very easily.

I add a couple of tablespoons of the crushed shells to my basic suet mix (see the recipe here) on the belief that calcium is likely hard to come by in the winter as well and this is just added nutrition and grit.

Sanitized eggshells may look a little brown, especially if you don't get them washed out thoroughly. However, they are sanitized.

In the spring, a tray of crushed eggshells next to your feeder will likely be popular.