Good question Muppeteer, I hope someone can answer that! I sometimes buy Duck eggs from a foarm shop, I think they're best for ommelets. I sometimes buy Guinea fowl eggs too , which are very good but have very tough shells and are difficult to crack without breaking the yolk's.
Also, in the poultry industry, production of eggs and production of meat are two separate entities.
Hens' eggs are produced by layer birds, bred to lay many eggs throughout their lives. Chicken meat is produced by broiler birds, bred to grow fast and have large muscles!
Turkeys are bred for meat, and not egg production. As In A Pickle said, turkeys are very seasonal and only breed at certain times of year, so it's harder to get eggs from them.