We bought 16 chickens (straight run, mixed breeds, brown egg layers) that were hatched June 6. One we thought was an buff orpinton has yellow legs the other 3 have a pinkish white. All have a tinge of black in their tail. Could they have some other variety mixed in with them? Why are they not crowing yet? The Silver Wyandott are but the buff and Golden Wyandott are not.