I almost stepped on this as I was walking up my front steps. I don't know if mama bird was particular about where she left her eggs or if some critter was interrupted in the midst of stealing.
It is clear to me from the camouflaging that this is not an bird egg at all. It is indeed the egg of the endangered concrete platypus. Note how it blends into the natural environment of the concrete step. Great eye to see this nearly invisible egg. Have you had any luck find the rest of the platypus family?
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