Instructions
Evaluate a group of geese by size. In most species of goose, including the African goose, the males are larger than the females by as much as 20 percent, though the coloration can be identical between the sexes. There are exceptions to this rule and you can only make such determinations within a group. This is not considered an exact way to determine gender.
Observe the behavior of a group of African geese. Geese are generally monogamous and the ganders tend toward protectiveness. They will often stand around the outside of a group of females defensively. While this is true of virtually all species of goose, you can only observe such behavior within groups.
Draw a blood sample for DNA analysis for the most conclusive results of the bird's gender. This is one of the least pleasant means of determining an African goose's sex, and it is also quite expensive.
Examine the bird's genitalia. Like all breeds of goose, the African goose male, or gander, has an internal penis. To sex the bird physically, hold it upside down with the rear end facing you, open the cloaca with your fingers (the opening serving the animal's reproductive, urinary and intestinal tracts) and look inside. If you see a corkscrew-like penis, it is a male; if not, it's a female.
African Geese: How to Tell a Male From a Female
Belonging to the genera Branta geese --- noted for their black bills, which are softer than those of the other goose genera, Anser geese --- African geese are actually native to southeast China and are a larger version of the Chinese goose. They possess a prominent dewlap and are one of the gentler breeds of geese. Somewhat common on American farms as pets, they usually weigh between 16 and 26 pounds, making them medium-sized geese.