Goose egg “addling” is a wildlife management method of population control for Canada geese and other bird species. The process of addling involves temporarily removing fertilized eggs from the nest, testing for embryo development, terminating embryo development, and placing the egg back in the nest. Returning the egg to the nest misleads the goose into believing the egg is still developing. Otherwise, the goose would begin laying again. Though considered more humane than hunting by some, it is not as cost-effective as other measures, such as extended hunting seasons and professional culling.
In order to work effectively, addling must be conducted in a manner that does not arouse the suspicion of the goose, and must not change the odor, appearance or texture of the egg. Effective addling techniques are disseminated by the Humane Society of the United States and Internet Center for Wildlife Damage Management. Perhaps the easiest way to addle is to coat the egg with corn oil, thereby depriving the embryo of oxygen and killing it.
Canada geese are covered in the United States by the Migratory Bird Treaty Act of 1918. It is illegal to harm Canada goose eggs in the U.S. without a permit from the U.S. Fish and Wildlife Service, Division of Migratory Bird Management.