Blastoderm or Blastodisc, help me decide if these eggs are fertile *photos*

[CorvusTristis18]

Hey! I have looked at these runner duck eggs for too long, can any experienced people help me decide?

 

[cheezenkwackers]

I have found with duck eggs that it seems like it is the size of the dot not a bullseye. A large dot, like yours, is fertile.

 

[CorvusTristis18]

I have found with duck eggs that it seems like it is the size of the dot not a bullseye. A large dot, like yours, is fertile.

Great tip, thanks. They were indeed fertile. All 15 that I put into the incubator (she laid over 18 and still wouldn't sit on her "nest") are showing strong development on day 7