Tuesday, February 16, 2010

A Hybrid Goose Found During the GBBC

Yesterday while watching birds at Johnson Park, I encountered a very odd goose. As you can see from the photo, it has a pale orange bill with a dusky tip, white feathers at the base of the bill, light cheek patch, dark brown crown and neck, grayish brown wings, light undersides with barred flanks, white undertail, and orange legs. The bird is most likely a hybrid, probably the offspring of one of the zoo's domestic Graylag Geese (Anser anser) and one of the semi-wild Canada Geese that forage within the zoo. This is a known hybrid type; Kevin McGowan has documented several examples around Ithaca, New York.

At Johnson Park, the line between "wild" and "domesticated" can be difficult to define. This bird was within the fenced boundaries of the park's zoo, but not within any of the completely enclosed cages. As far as I can tell, the zoo's waterfowl do not have their wings clipped, so that birds inside the fence are not necessarily owned by the zoo, and birds outside the fence are not necessarily wild. Many nominally wild Canada Geese and Mallards congregate around the open water and free food offered within the zoo's fence. While there they mix freely with the zoo's domestic geese and ducks. I have seen birds similar to this one on a few occasions at this and other local parks, so that interaction between wild and domestic birds clearly includes occasional breeding.

Visitors often feed the birds in and around the zoo, so that some of the waterfowl have lost their fear of humans. As I knelt to photograph the hybrid goose, one of the Canada Geese that was with it walked up, stuck its bill through the fence, and started pulling on my glove. It must have expected me to give out food instead of just take pictures.