Currently, there are seven subspecies of Canadian geese in North America – cackling goose, Aleutian goose, Taverner’s goose, lesser Canada goose, dusky Canada goose, Vancouver Canada goose, and western Canada goose – ranging in weight from 3 to 11kg, in size from76 to 110 cm, and in wingspan from 1.3 to 1.7 meters. However, despite size, weight, travel habits, and other variations, all Canadian geese have similar physical characteristics. The head, bill, legs, feet, and tail are black; the back, sides, breasts, and wings are beige to light brown; the neck is black, and there are white patches on the cheeks that connect under the chin like a strap. There are no notable differences between the genders, although females are usually slightly smaller than males. In the summer, adults lose their flight feathers and get new ones in time for the fall migration, but are unable to fly for a whole month during this process.
Goslings are light yellow with greenish-gray feathers on their backs (and sometimes heads, depending on the subspecies). When hatched, their feet are black and the bill is covered in ridges (lamellae) around the outside edges to help them feed. Their color darkens as they mature; they attain full plumage in 3-4 months after hatching. In flight, Canadian geese display large, black wings that contrast with the U-shaped white band on their rump, and can be recognized by the distinctive V-shaped flock formation.
To stay healthy, Canadian geese’s diet must comprise grass (salt grass, Bermuda grass), leaves, seeds, roots, berries, and pond plants such as cattail, algae, sedge, tubers, and roots, but they can also get their nutrients from a variety of agricultural crops such as alfalfa, oats, wheat, corn, rye, and barley. Goslings in need of extra nutrients are taught to use their sensitive bills to search for aquatic invertebrates, small fish, insects, and mollusks. Geese spend up to 12 hours/day eating, but can survive up to one month without any food. In urban environments, geese like to feed on lawn grass. They prefer to remain in open areas, avoiding shrubs or tall grass, where they can spot predators and other dangers. They also like to live near ponds, rivers, and marshes. Because they are highly adaptable, geese can live nearly at all elevations, from coastlines to mountain regions.
Females search for a good nesting site where they build the nest in a bowl shape using grass, mosses, sticks, and twigs, and insulate it with feathers from the her breast; preferred locations include islands on bodies of water, at the base of trees, in flower boxes, in cattail, under shrubs, and in any other place that offers them isolation and concealment. Once finished, the nest will be reused every mating season from then on.
After the female lays 2 to 10 eggs and incubation begins, both the male and the female will protect the nest for the entire duration of the hatching process (28 to 30 days). Once they leave the egg using their bill “teeth” to cut it open, goslings start looking for food and water as quickly as 24 hours after hatching. They will not, however, be ready to fly until 44 days since hatching. The brood is fiercely protected by their parents for their next 10-12 weeks of life, until goslings are able to fly and can protect themselves from predators. During this period, it is not unlikely to see adult geese with 10 to 100 goslings following them, especially in areas with a high nest density.
When winter comes and all bodies of water freeze over, Canadian geese migrate to warmer places where they can find food and shelter. During migration, which begins in late August or early September, they usually follow the same routes every year, including the Atlantic flyway (along the North American coastline), the Central flyway (along the Rockies), the Pacific flyway, and the Mississippi flyway. They travel both by day and night, stopping to rest from time to time at familiar places such as farmlands or marshes.
In flight, they use honking to communicate with each other; between the genders, the male’s sounds are usually louder, but females give higher-pitched calls. They also hiss whenever they sense danger close by.
Canadian geese are often regarded as pests because they:
As in the case of many other pests, a single control method is not enough to eliminate Canadian goose invasions. Rather, property owners should ask the help of pest control professionals who can devise an integrated management program that includes a combination of the following safe and effective approaches:
Habitat management. Property owners can modify existing vegetation and bodies of water to decrease their attractiveness to pests (ideally, this can be carried out without affecting the usefulness of the property for its initial purpose). In terms of vegetation, lawns can be replaced with ivy, vetch, and wildflowers; keeping grass tall will also deter geese, known for their preference of open grass fields. When it comes to water, property owners can remove retention basins and install barriers and perimeter fencing around lakes and ponds (effective especially during molting season when geese cannot fly) to limit geese’s access to water. Flagging, scarecrows, and balloons have been shown successful to some extent at deterring birds from small areas.
Harassment.The success of this control method depends on the technique used, whether it’s trained dogs, cannons, pyrotechnics, lasers, horns, distress calls, or others. It’s important to note that some harassment methods such as the use of pyrotechnics must be permitted by state laws – and only under the condition to not harm or kill geese. Although harassment with legal and safe techniques can provide some relief and is an important part of the integrated goose management program, it’s not a permanent solution, especially for large-scale invasions.
Population management.Upon obtaining federal authorization, landowners can proceed to destroy nests and eggs of Canadian geese to control their population. Removing nests is also a preventative method as geese often come back to the same nesting the following season. Also requiring a federal permit, hunting geese or shooting them down when on your property are also effective ways of controlling goose populations before they get out of control. Those who cannot obtain a permit for killing geese can limit themselves to capturing and removing the birds from their property, which is easily done during molting season.
Repellents. Spray formulations containing methyl anthranil and anthraquinone can be applied on the grass in small areas (driveways, parking lots, picnic areas) to deter geese. Pest control professionals can also recommend certain formulations designed for application in non-fish bearing bodies of water. Due to the cost of material (up to $250/acre), it may not be cost-effective to use repellents on large surfaces.
Here are some tips to keep or decrease goose populations in urban and suburban environments: