You're throwing it in the garbage now and if you find one again in the future, you'll leave it where it is.
Bird eggs lying around somewhere do not do that for coincidence but because the bird who has laid it already knew that it doesn't make any sense to invest energy.
You can't do anything. If the occupancy is too dense in an area, they like to clear each other's nests.
Which bird it is, I don't know, maybe a tit.
As long as you don't have a brooding apparatus, you can't do much, and even if you had one, the egg is probably there for a time.
I don't know what bird it comes from.
You're throwing it in the garbage now and if you find one again in the future, you'll leave it where it is.
Bird eggs lying around somewhere do not do that for coincidence but because the bird who has laid it already knew that it doesn't make any sense to invest energy.
If you leave it, another animal has another meal.
Throw away? If that was on the street, it's probably already a pity.
Look here.
https://www.naturparkmagazin.de/vdn