When I was a kid, our very first flock of hens included a funny-looking little EE mix that was my sister's favorite. She was white with a brown chest, green shanks, muffs and beard, a prodigious fan tail, and a single comb that bent sharply right, then folded over to the left and lay on top of her head like a tricorn hat. Her name was Chicken Little, and she was the top hen in the flock. She developed an internally ruptured crop at three years old that didn't even slow her down; she bustled around the coop and yard with her bulging front giving her quite the matronly figure, putting the smackdown on much larger hens. She outlived all of her agemates and a large number of younger birds, and was thirteen years old when she passed away.
After Chicken Little, I get pretty upset to lose a hen at four years old because of stuff like egg yolk peritonitis. I think it's time to select some birds for longevity and health! Chicken Little was one heck of a mutt, and I'm sure that contributed tremendously to her toughness.