My understanding is this kind of thing is more common in birds that recently started laying. Combine that with the fact that birds tend to be kept with other birds of similar age and it’s not uncommon for a package of eggs to have either no double yolks, or multiple instances of double yolks. I’ve never seen a dozen eggs with just one double-yolk.
I have some chickens that just started laying a few weeks ago, so far I’ve found two with double yolks. Cool stuff!
Oh fun! I’m surprised it’s not more rare than that
My understanding is this kind of thing is more common in birds that recently started laying. Combine that with the fact that birds tend to be kept with other birds of similar age and it’s not uncommon for a package of eggs to have either no double yolks, or multiple instances of double yolks. I’ve never seen a dozen eggs with just one double-yolk.