Tuesday, July 7, 2009

Autosexing Geese

Autosexing Geese are breeds in which hens and ganders are easily distinguished because of sexual dimorphism in color. Ganders are white and hens are solid color or saddlebacked. This characteristic dates back 1,000 years or more in England and France, longer in Scandinavia. They probably originated in Scandinavia and can be found in areas where Vikings set their anchors.
Being able to tell the sexes apart is a significant advantage in raising geese. In most breeds, males and females are so similar that it's not unknown for a breeder to set up breeding pens that are all one sex. It's possible to examine geese physically to determine sex, but it's difficult and, unless done carefully, can permanently injure the gander. Ganders have a penis, but the genitals have to be inverted by applying pressure with the fingers. Definitely a technique that is best taught by an experienced goose handler.

Males tend to be larger than females, but there's a lot of variation. A small male could be mistaken for a female. Among geese with knobs, the Africans and Chinese, males generally develop larger knobs than females, again with the caveat that there is a lot of individual variation among birds.

Autosexing breeds include: The West of England and Choctaw, important regional types in American agriculture. West of England include gray blotched, saddlebacked or purely gray hens and white ganders. West of England geese may well have been the ones that arrived on the Mayflower. At one time, this goose was well established in New England. They are also known as Old English.

The Choctaw is also called Cotton Patch and Cottonfield Geese. They were originally common in cotton-producing areas from Mississippi to Oklahoma. They probably developed from the West of England and Normandy with some Gray goose infusion. They are very similar to the West of England.

Other autosexing breeds include the Pilgrims, right, a modern American breed that was developed in the 1930s by Oscar Grow, probably from mixed West of England and Gray stock. These birds are photographed at Metzer Farm, a duck and goose breeding farm here in California, http://www.metzerfarms.com/. The Pilgrim is a gray goose with the autosexing gene added. Compared to the historic autosexing breeds, the Pilgrims are relatively common.

Shetland hens are gray saddlebacks with wide pattern variations. Ganders are white. With yellow bills and pink legs like the Western Greylag, they are the smallest of the autosexing group. They may well be the original type of autosexing geese. They were first imported to the U.S. in 1997.

2 comments:

Amri said...

When we move to a larger property it might be nice to have a few geese but we'll decide that AFTER we move. I like what I've read about Pilgrim geese. Thank you for writing this great blog!

PoultryBookstore said...

Thanks for the kind words, Amri. For those who have the space, geese are a welcome addition.