Auto Sexing Geese

Craig Russell

with permission from
SPPA Bulletin, 2003, 8(4):6-7

The origin of auto sexing geese was almost certainly prior to the 11th century and the original development may have been by chance. The only uniquely American member of the group is of relatively recent development. The Pilgrim goose breed was developed in Iowa by the renowned poultry and livestock breeder and judge, Oscar Grow, during the first half of the 20th century. For the record, Mr. Grow credits the name of his auto sexing geese to his wife, who reportedly gave them the name “Pilgrim” when they were moved from the family farm in Iowa to Missouri during the 1930s. The Pilgrim may have some genetic link to earlier sex linked geese. In his book Modern Waterfowl Management and Breeding Guide, Mr. Grow gives little detail about the Pilgrim's actual development. He made the claim that prior to the Pilgrim "there never had been a breed of true geese" with a sex linked genotype. However there have been reports that Mr. Grow obtained the foundation stock for the Pilgrims from a correspondent whose geese tended to be sexually dimorphic but were not perfectly so. If I remember correctly those geese were from New England or the owner's family was originally from that area. If that report is correct the foundation for the Pilgrim breed comes from an area that reportedly was populated with West of England geese during the colonial period. Mr. Grow rejected "Designs by exploiters to connect this breed of geese with reputed earlier sex-linked European breeds."

Bruce Lentz believed there was a connection and felt that Mr. Grow was trying too hard to avoid it. Bruce said, "Oscar Grow knows more about waterfowl than I do and I can tell you there were sex-linked geese before there were Pilgrims and some of those are still around. In England and Europe they have 4 or 5 kinds. If I know that Oscar Grow should know it, too." Bruce believed that anyone who could write in detail about English geese had to have knowledge of English sex linked breeds (West of England geese). He also reported that there were probably still such geese in New England as they existed when he was a young man. He knew with certainty a flock existed in southwestern Pennsylvania.

Dale Rice was willing to give Mr. Grow the benefit of the doubt. Perhaps he doubted that Oscar Grow knew more about waterfowl than Bruce, but he certainly doubted that Mr. Grow knew much about non-recognized European breeds. Dale felt that having worked hard on the Pilgrim, it was natural for Mr. Grow to resent what he saw as attempts to steal his thunder. Dale agreed with Bruce that the Pilgrim was genetically linked to the European auto sexing geese. Dale was fairly certain that the same mechanism was responsible for sex linkage in all the auto sexing breeds of geese and he felt a genetic connection was more likely than independent identical mutations.

Whatever his actual knowledge, Mr. Grow tried hard to discredit the idea about other sex linked geese. He suggested that early reports of white ganders and gray females were simply attempts to produce light colored geese "preferred in the early markets." Actually gray geese remained the preferred type in most of western and northern Europe well into the 19th century. In North America gray geese dominated production into the 2nd half of the 20th century, despite the fact that white geese have been popular in Italy and southeastern Europe since Roman types. Mr. Grow tries to hedge his bets, "even granting there may have been some accidental instances of color dimorphism in earlier times, the genetic significance of such a phenomenon could not have been understood and therefore would have soon been dissipated through aimless selections . . . Moreover, sex linked color patterns alone do not identify the Pilgrim. There are shape requirements quite as important as its color distinctions." When these words were written auto sexing geese had avoided dissipation for 1000 years or more, and at least 3 breeds besides the Pilgrim (one with two varieties) were in existence.

Even in England and Europe, at least in recent times, the distribution of auto sexing geese has been rather local and many knowledgeable poultry people are not aware of them. In her 1980 book Keeping Domestic Geese, English writer Barbara Soames has this to say about auto sexing geese. "These two breeds (meaning the Pilgrim and West of England) are the only truly auto-sexing ones at hatch." Ms. Soames does not mention Norman or Normandy geese but she considers them to be identical to the West of England variety. She believes that probably long before European colonists came to America, certainly before 1600, the English had developed a breed of auto sexing geese. She also points out most of the Pilgrims were West Country people. While the original English settlers in America didn't call their geese Pilgrims, later immigrants seeing them on New England farmsteads did. This agreed with what Bruce Lentz considered the traditional American view. Ms. Soames hedges her bets a bit, too. After mentioning Normandy geese, she points out that in 1066 William Duke of Normandy conquered England and many of he supporters chose to move to England, "lock, stock and barrel –- perhaps geese, too." But she is quick to point out that the Normans might have seen English auto sexing geese and taken them "back to friends and relatives."

The geese Reverend Jenyn wrote about in his 1800 book Vertebrate Animals were certainly auto sexing. He reported they were the only breed in the country. But as little as 15 years later importation of large numbers of Embdens and other European breeds started to sweep auto sexing geese from Eastern England. Later in the century Toulouse were also imported in large numbers. I probably should point out that it isn't certain whether Reverend Jenyn was writing about the entire country or just specific sections. Some writers feel that outside of the West Country the traditional English geese were non-auto sexing Grays, Saddlebacks and Whites, although the Whites were not very common. This idea seems to be supported by the American situation where Gray geese seem to have been well established outside of New England long before the 19th century and presumably some if not most of these geese came from England.

In the early 1970s I talked to a German breeder who seemed well versed on auto sexing geese. He believed that Scandinavia was the original source of auto sexing geese. He pointed out that Normandy, the West of England, and the Shetland Islands were all areas invaded and colonized by Vikings. He also claimed that auto sexing geese had been common in those areas until foreign imports had replaced or modified them.

It is likely that the same process occurred in New England. While it is apparent that the Shetland, West of England and Normandy geese are related, they are not identical. The West of England is the largest, even nominally larger than the Pilgrim. This is the breed with on average the lightest colored females. Their heads are usually largely white.

Despite being smaller the Normandy has a slightly chunkier appearance. Like the West of England it has orange or orange-yellow bill and legs. This is the breed with two varieties. The Bavent is a tufted version, but otherwise very much a typical Normandy. The tufted characteristic was likely borrowed directly or indirectly from Tufted Roman or Danubian geese in relatively recent times (the last 2 or 3 centuries). The Shetland is the smallest of the group and has pink legs and yellowish bills tending to reddish pink at the base.

If auto sexing geese moved from Normandy to England or from England to Normandy they were well established before 1066. If they came from Scandinavia they were established much earlier. No matter when or where they originated, the leg and bill color of the Shetlands raise some interesting questions. Auto sexing in geese depends on a gene carried on the X chromosome that restricts the expression of ground color. Males with two X chromosomes end up largely white, while females with one X chromosome and one 0 chromosome have only one restricting gene, which results only in a lighter tone of gray and patches of white or frosting over the head and near the bill. These restricting genes are imposed on a gray base, in the case of the Pilgrim. With the Normandy, West of England and Shetland, the restricting genes are imposed on a saddleback base.

Years ago I spent some time with Dale Rice speculating the origin of the auto sexing characteristic. Dale shared my interest in such things but had never been able to establish a reasonable scenario or likely source for the development of the trait. He felt like when considering the length of time geese have been domesticated and comparing their relatively low level of mutations with the chicken, auto sexing wasn't a very surprising mutation. Knowing that cross breeding distinct populations produces new genetic combinations that may cause new phenotypes, and thinking about the white on the face of the White Fronted group, I couldn't help but wonder if the gene responsible for auto sexing, when combined with different modifier genes from the Graylag, could be responsible for sex linked characteristics. Dale said he considered the same thing but felt that some domestic breeds showed this trait and were not sex linked. While that didn't rule out some other recombination as the cause, he couldn't think of any obvious examples. I was never completely convinced that I wasn't on the right track, and that crosses of different members of the two groups or even different combinations of the same cross couldn't produce different results.

However, the Shetlands, with yellow bills and pink legs like typical Western Graylags, and which are also the smallest member of the auto sexing group, raise the possibility that this trait was a simple and perhaps very early mutation from early pre-Western Greylag domestic stock. The size of the Shetland could be a result of a large goose adapting to a relatively harsh island environment. When considering what seems to be a pure Western Graylag characteristic along with small size raises the likelihood that this is the original type, and that others are the result of some mixture of other populations.

While Graylags with orange or yellow bills and feet exist they are not typical. The normal Western Graylag has the same combination as a Shetland, although the reddish pink at the base of the bill would not be typical. The fact that many western European breeds have orange bills and feet is one of the arguments in favor of ancestors for domestic geese other than Graylags and Swan geese. Although a variety of wild traits have been reported in domestic populations, the Bean goose is the most often suspected as being responsible for the orange feet. It is the only other European goose as large as the Graylag. Hybrids of the two are often larger than their parents. However, both Lesser and Common White Fronts have orange legs and the Greenland Race of the Common White Front has an orange bill and lacks the dark marks that the Bean goose has on its bill. Since orange legs are very rare in Graylags it doesn't seem likely that this trait comes from those few individuals with it. Swan geese lack knobs and most of their pure and high percentage domestic descendents have them.

Oscar Grow stated that "The slightest infusion of alien blood will irretrievably upset the sex linked balance. Once foreign blood is introduced there is no way of restoring the genetic pattern responsible for 100 percent sex linkage." It struck me when I first read this quote that if it were true, Mr. Grow would not have been able to put the Pilgrim breed together in the first place. Dale Rice was certain that simple grading would yield a pure sex linked population in just a few generations. While representing major projects, producing sex links in other colors such as Buff or Brown (males would be largely White), would be entirely possible. Bruce Lentz believed that a breeder who knew what pure breeds of both sexes looked like would have little trouble producing a pure strain from mixed stock, even if the breeder didn't understand the genetic science involved.

With this article I include a few general notes on reading. I first devoured Oscar Grow's Waterfowl Management and Breeding Guide shortly after I returned from Germany in the 1970s. My friend, Vic Corson, possessed a first edition, which was among the first waterfowl books I read. I enjoyed it thoroughly even though it left me with a few questions. Despite later hearing much criticism about the book, I added the 4th edition to my reference library. Researching the series of goose articles I've been writing reacquainted me with the book. Yes, the criticism of the book remains valid. The book has some flaws, but they are restricted to a few items. In general this is a fine work that anyone interested in poultry in general and waterfowl in particular should read and keep handy. The ABA is to be commended for helping to bring it to the public. This is the sort of enterprise the SPPA needs to initiate as it grows and prospers.

The 1980 Keeping Domestic Geese by Barbara Soames is perhaps the best all around, recent (although 20 years+ ago) book on geese. Dave Holderread's 1981 work, The Book of Geese, A Complete Guide to Raising the Home Flock, is a wonderful how-to manual that every prospective goose keeper should consult.



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