Branta Canadensis maximaPhoto by John Hess

“What a dull world if we knew all about geese.”Aldo Leopold, A Sand County Almanac, 1949

Aldo Leopold need not have worried; there is still much to learn. Scientists are using DNA research to sort out the many geese subspecies. Goose ecology, reproductive biology, formation of pair bonds, brood-rearing areas, benefits of flying in V-formation, nutrition, possible vectors in the transmission of disease, and management of large populations are among the topics needing research.

The word “goose” has been absorbed into the popular vocabulary from duck duck goose and Mother Goose on to cooking one’s goose, goose-stepping, goose bumps and silly goose, etc. Samuel Johnson’s classic 1755 English Dictionary definition is “Large waterfowl proverbially noted, I know not why, for foolishness.”  

Canada geese are native only to North America. Before Europeans disrupted the ecology of the Chicago area, migrating nesting geese were plentiful. According to Joel Greenberg’s A Natural History of the Chicago Region, “in the 1850s Canada goose eggs were gathered by the bushel in a marsh north of Racine and were described as being abundant in Cook County.” By 1876, E.W. Nelson noted that the breeding population had declined; hunting and habitat loss (wetlands) were the all-too-familiar culprits. In 1899, Lincoln Park Zoo authorized the expenditure of “$18 for three pairs of rare Canada geese” In the 1950s, the wild Giant Canada Goose was considered extinct, but in 1962, Harold Hanson of the Illinois Natural History Survey found a remnant population near Rochester, Minnesota.

In the 1930s, scientists began reintroducing geese from captive populations kept for food and decoys. The law of unintended consequences prevailed. The introductions coincided with the post-World War II icon of suburbia: the perfect lawn. The Canada geese adjusted to the evolving landscape of yards, golf courses, parks, school playing fields, corporate expanses of grass near man-made retention ponds, and the proximity of large agricultural fields with minimum stubble. With these features available year-round, there was no need to migrate unless ponds froze. The Evanston North Shore Christmas Bird Counts tells the local story. In 1963, zero geese were recorded, in 1967, there were 9, by 1961 there were 2,304, and in 1993 a whopping 9,206.

Migrating geese have long been embraced as the heralds of the spring and fall seasons. Strong flyers honking along, they typically fly in V-formation or straight lines. The lead birds rotate, probably because of the energy required to be out in front.

A flock of geese is a gaggle, a male is a gander, and a female is simply a goose; chicks are goslings. Male and female look alike. Both sexes have a black head and long black neck, black tail, a flat black bill, large wide blackish webbed feet, and white patches, or “chin straps” on the cheeks. They have light tan chests and brownish-grey plumage elsewhere, as well as white on the belly and under the rump. Their bills have miniature ridges around the outside edges, useful for cutting food. Immatures are duller with brownish chin-straps. Adults weigh on average 5-14 pounds, the male being slightly larger.

Canada Geese are vegetarians. They feed on domestic grasses throughout the year. They also forage farm fields for higher carbohydrate foods such as seeds, wheat, beans, rice and corn. With their long necks and strong jaws, they forage for submerged aquatic vegetation in wetlands. Food can move through their digestive systems in as little as an hour. They eat almost continuously to get enough nutrition. In the process they leave large amounts of feces.

Canadas mate for life, usually during their second year. If one dies, the remaining bird will find another mate. During courtship, as early as February, they perform a “greeting ceremony,” a complex routine that features duet honks of the male’s “snore and a honk” calls accompanied by his rolling display, and the female’s “hink” call.

The pair arrive at their breeding territory together, most likely the female’s natal breeding ground. She alone chooses the location and builds the nest on a dry spot out of the wind and sited for maximum solar gain. She needs some distance from other goose nests, good visibility to watch for predators, and water within 150 feet. Nests are shallow bowls made of sticks, grasses and weeds, lined with softer plant material and insulating down feathers plucked from her breast.

Giant Canada geese have one brood a year, and both sexes raise the young. The female lays an average of five eggs one and a half days apart. Once the last egg is laid, the female begins to incubate. The male defends the territory. Woe to the predator, including human, who comes too close to nest or offspring. A male’s hiss, an outstretched neck and pumping wings can signal threat and intent to attack.

Goslings hatch after 25-30 days and can walk, swim, dive and feed themselves within 24 hours. The family roams together to safe feeding grounds, one parent strutting in front with the other bringing up the rear. A safe location is often a large body of water with good sightlines for predators, a necessity because, prior to leaving their breeding ground, both parents have molted their flight feathers and are flightless. Geese are strong walkers, fast runners, and surprisingly agile, important attributes when flightless.  After 5 weeks, the adult flight feathers have regrown. Twelve weeks after hatching, the young are capable of flight, and the family moves together to their wintering grounds. There, they join numerous others, occasionally quarrelsome and uttering, as Leopold comments, their “half-audible small-talk that never ceases among geese.”

Concentrations of geese are a problem. They damage crops. Their droppings contaminate lawns and lower water quality. They damage turf by grazing. They create safety problems when flying near airports. Scare them from one area and they will find another. The management of these magnificent birds, whose overabundance resulted from good intentions, continues to be a challenge.

Libby Hill

Libby Hill is the author of "The Chicago River: a Natural and Unnatural History. She has been writing about birds and trees and Evanston's natural history for the Roundtable since 2004.