California Geese 101
By Luke Matthews
Throughout the year, there are six different species of geese that can commonly be found in California. These are geese are further broken down into two categories: white geese, which consists of Snow Geese and Ross’s Geese; and dark geese which consists of Greater White-fronted, Cackling, Canada, and Brant Geese. Brant are a coastal species found in association with eel-grass, their primary food source. With the exception of Canada Geese, which can be found in California year-round, all of these geese spend their summer in Alaska, Northern Canada, and the Arctic only migrating down to California in the winter.
White geese are much more abundant than dark geese. In fact, white goose numbers have been steadily rising and recent counts estimate that California supports an average of over 1.2 million Snow Geese and Ross’s Geese each winter. Although the numbers are not as impressive, the dark goose population has been on the rise. Excluding Brant, recent counts estimate that California supports an average of 740,000 dark geese each winter, with the vast majority of those being Greater White-fronted Geese.
The increase in goose numbers has started to raise concern in the conservation community and many researchers have already embarked on studies to determine the impacts of these rapidly growing populations. While it has been documented that high goose numbers can lead to the destruction of arctic habitat on their breeding grounds, there are still many unanswered questions regarding their impacts on the wintering grounds. Reduction of food availability for dabbling ducks, increased risk of disease outbreaks, and crowding of high-quality roosting and loafing habitat are a few of major concerns in the Sacramento Valley.
Luke Matthews is the Wildlife Programs Manager for the California Rice Commission
