types of bird eggs

First barred owl eggs they look like chicken eggs, but they are not.
Second red-tailed hawk eggs they look like chicken eggs but with brown dots.
Third pelican eggs and again they look like chicken eggs but bigger size.
BUT WHY DO THEY ALL LOOK LIKE CHICKEN EGGS!!!.
I'm wondering why they all like chicken eggs???.
Okay I probably know why or...maybe I don't know.
Okay just look it up on google if you want to see more chicken eggs!