Egg in the garden

Bug Mad Girl writes:

Today I walked out of the back door and saw an egg shell by the fence! I think it's a Pigeon egg because it is quite big and white. You can see a membrane in the shell and some blood vessels. A baby Pigeon would have hatched out of it and the parents would have removed the shell from nest. They probably dropped it by the back door. I'll have to have a look for the nest in the garden.