Are all eggs laid by wild birds fertilized?

Question

bc i had an egg that didnt hatch and i cracked it open and it was just yellow stuff

Answer 1

No they are like chickens not all egg are fertil

Answer 2

most wild birds eggs are fertile mother nature does not waste much energy to reproduce and a non fertile egg is a waste

Answer 3

No, not all of them are.

Answer 4

no, not all eggs are fertile. i once found a starling egg and i kept it with a heating pad but it never hatched so my mother cracked it open and there was no blood spot in the yolk (it was not fertile) oh and chicken eggs are not fertile because the farmers do it on purpose. its not a chance that they will/will not be fertile because they all will be unfertile.