From what I've read over the years, since the SL are the base of the wyandotte breed, they also come with a lot of genetic problems due to all the inbreeding through the years. They are prone to congenital heart problems, they have more fertility issues and adult birds tend to need more time than most other colors to become fertile in spring months. We just wait it out and collect like crazy when thy do lay. Warmer states might not have as much issues either-but here in the North, it takes them longer.