Here is the basic info on Pilgrim geese from the Livestock Conservancy:
The Pilgrim goose is known for being calm and personable. It is one of two American goose breeds that is sexually dimorphic (auto-sexing), the other being the Cotton Patch breed. Day-old males are silver-yellow with light-colored bills, in contrast to the olive-gray females with their darker bills. Adult ganders [males] are mostly white, usually with gray rumps (which are covered by the wings) and traces of color in the tail and wings. Mature geese [females] are soft dove-gray with varying amounts of white in their faces. Bills and legs are orange in both sexes, while the eyes are blue in ganders and dark brown in geese.
Pilgrims are medium-sized geese, weighing 13 - 14 pounds at maturity. The head is trim, the crown is often slightly flattened and the neck is average in length and thickness. Their bodies are full and plump, with a smooth, keel-less breast. They should have two rounded fatty lobes on the abdomen. Properly managed, they lay 35-45 six to seven ounce white eggs annually.
"Pilgrims are rugged, quiet, docile, good foragers, excellent natural parents and make good medium-sized roasting birds. Because they are sex-linked for color, it is a simple matter - even for the novice - to keep the correct ratio of males to females when selecting young for future breeders. Ganders can be mated with three to five geese" (Holderread, 1981). When selecting for breeding stock "look for broad backs and breasts that are keel-less. Stay away from using birds with any sign of a knob (an indication of crossbreeding), long necks and legs, shallow breasts, ganders with excessive gray in the plumage and geese with predominantly white necks. Because Pilgrims are noted for being sweet-tempered, this trait should be considered when retaining birds for reproduction" (Holderread, 1981). For those seeking a medium-weight goose, Pilgrims are an excellent choice for the home goose flock.
(Picture from the Livestock Conservancy: http://www.livestockconservancy.org/index.php/heritage/internal/pilgrim)