Having been one of the first people to acquire Pearl Winter White hamsters, I have now been breeding them for ~ 9 years. It soon became obvious that the male Pearl was sterile, and you have to put a Pearl female to a normal or Sapphire male to produce offspring. As the gene is dominant, Pearl babies are produced.
Over recent years I have not bothered to pair up Pearl males, but sold them as pets or for showing. However, one or two recent reports of Pearl males fathering litters got me thinking. Back in 1990 a Pearl female and normal male of mine produced a litter with a Pearl male in it with a patch of normal coloured fur on his bottom. I wondered if this would mean he was fertile and paired him up, but no babies were ever produced. In February this year I had a second Pearl male produced with a patch of normal fur on his back, a much smaller patch and almost hidden by his dark stripe. I paired him up with a Sapphire female and much to my amazement they have had a litter consisting of: 2 females, 1 male normal and 1 female, 1 male Pearl (neither has a patch).
I would very much like to collect all the available information on known fertile Pearl males, particularly if they have a patch of coloured fur or not. Details of what they were mated to and what colour the babies were would also be helpful. Details of parentage would also help establish if any of the males are related.