Hey everyone it's my first time hatching quail eggs and before I put them in the incubator I was wondering if these were fertile or not (I'm gonna hatch out 3 eggs in total but I'm waiting for my quails to lay one more)
For chicken eggs, day 4 of incubation will show the initial blood vessels, there should also be a visible air gap.
Idk if quail eggs are much different in these scenarios, but I would check for that. (I often can't tell until they actually start growing, if they remain the same they aren't fertile)
Nobody will be able to tell you if they are fertile or not at this point. You will have to put them in the incubator and start the process for a few days. Then you can see... Just looking at eggs does not work.
If quail eggs are anything like chicken eggs, you can open them up and look at the spot on the egg yolk. You can see then if they are fertile or not. If they are you can assume that the others will be too.