Geese, particularly the well-known Canada Goose (Branta canadensis), are famous for their long-distance seasonal migrations, yet many people now observe them year-round in parks and urban areas. This deviation from the expected behavior is not a loss of instinct but rather the result of distinct population lineages and a landscape fundamentally altered by human activity. The geese seen today are often part of a non-migratory group that has found a successful survival strategy in the milder, resource-rich environments of the southern and central parts of North America.
The Difference Between Resident and Migratory Geese
The Canada Geese that remain in one area throughout the year are classified as “resident” populations, which are biologically and historically distinct from their migratory cousins. While the classic migratory flocks breed in the Arctic or sub-Arctic regions of Canada and Alaska, the resident geese nest much farther south, often within the lower 48 U.S. states and southern Canada. These southern-breeding populations largely descend from restoration efforts in the 20th century, which used non-migratory or captive-bred stock to repopulate areas where the species had been eliminated by overhunting.
The Giant Canada Goose (Branta canadensis maxima), once thought extinct, is a primary example of this resident group. Its larger size and temperate breeding grounds mean long-distance migration is less necessary. This population was never taught, nor did it develop, the strong migratory instinct of the northern-breeding subspecies. Consequently, resident geese either do not migrate at all or only make short, localized movements to find open water and food during periods of severe winter weather. The two populations remain genetically and geographically separate in their breeding ranges.
How Human Development Provides Ideal Conditions
The success of these resident populations is linked to human-developed landscapes, such as suburban parks, corporate campuses, and golf courses. These settings provide a year-round abundance of high-quality food, primarily in the form of manicured, fertilized turfgrass, which is an ideal grazing source for geese. This continuous food supply eliminates the necessity of flying thousands of miles to find winter forage.
Human development frequently includes retention ponds, decorative lakes, and other open water sources that are kept aerated so they do not freeze completely during the winter. These water bodies offer safe resting and roosting sites, which are often paired with a reduction in natural predators like coyotes and foxes. The combination of plentiful food, secure water, and low predation pressure creates an artificial habitat that is significantly safer and more resource-rich than many natural environments.
The Biological Advantages of Skipping Migration
Remaining in a temperate, resource-rich area represents a substantial energy saving compared to undertaking a long-distance migration. The twice-yearly journey is a physically demanding endeavor that requires high energy expenditure and exposes the birds to high risks. By forgoing this journey, resident geese conserve the energy that migratory birds must use to fuel their flight muscles and maintain body mass during transit.
This energy conservation leads to a better overall body condition, which directly translates into enhanced reproductive success. Resident females often begin nesting at a younger age and produce larger clutches of eggs than their migratory counterparts. The milder climate and extended growing season in the south also provide a longer breeding window, further contributing to the rapid growth and high survival rates of these resident populations.
Managing Geese That Stay Year-Round
The unchecked growth of resident goose populations has led to frequent conflicts with humans, primarily due to the large amount of feces they produce, which can affect water quality and public health. Consequently, municipalities and property owners often implement integrated management strategies focused on making developed areas less appealing. One common non-lethal method is habitat modification, which involves replacing expansive, short-cut lawns with tall, dense vegetative buffers near water bodies.
Geese prefer open sightlines to detect predators, so these tall grasses and shrubs obstruct their view and act as a deterrent. Other tactics include harassment, such as using trained dogs, visual deterrents, or noise devices to condition the geese to avoid an area. When population control is required, methods like egg addling or oiling are used. These methods render the eggs non-viable while leaving the nest intact, preventing the parents from attempting a second nest.