Resident Canada Goose (Branta canadensis)
Photo credit: Viktor Dahl, https://flic.kr/p/RV98Nv

Resident Canada Goose

(Branta canadensis)

Report this Species!

If you believe you have found this species anywhere in Pennsylvania, please report your findings to iMapInvasives by submitting an observation record.

Species at a Glance

The feral hog, also known as the feral pig, feral swine, or wild boar, is a feral representative of the same species including all domestic pigs. Brought to North America from Europe and Asia as a domestic livestock, or through introductions of wild boar, the feral hog has since established wild populations that pose serious ecological, economic, and public health threats.

Identification

The feral hog exhibits a wide range of colors and sizes. The average sow weighs 35-150 kg (77-330 lbs) and the average boar weighs from 59-200 kg (130-440 lbs). The hair is coarse, with long bristles. Color ranges from solid black, gray, brown, blonde, or red to striped, spotted, or grizzled color combinations. The elongated snout is flattened at the end and is tough and flexible. Males have four tusks that grow continually and can be extremely sharp. Upper tusks can be as long as 8-13 cm (3-5 in) and are usually worn or broken from use. The feet are cloven and the tail is often straight and moderately long, with sparse hair. Signs of the feral hog can include tracks, rubbings on nearby trees, rootings, and muddy wallows. In some areas, escaped or free-ranging pigs may be legally considered feral based on their location and lack of documented ownership, rather than on physical appearance.

Similar Species

Not to be confused with recently escaped domestic pigs, the feral hog roams free and is not tame. Escaped, or freeranging “domestic pigs” left unattended or abandoned to roam free may quickly convert to feral condition.

Habitat

The feral hog can adapt to almost any kind of habitat, from tropical coastal marshes to sub-arctic latitudes. In the Mid-Atlantic region, it prefers habitats with an abundant supply of food, water, and dense cover such as swamps, shrubby communities, riparian zones, forests, agricultural fields, and urban or suburban greenways.

Spread

Through natural population growth, illegal movement by sport hunters, and escape from domestic swine operations, the feral hog has quickly spread and established wild breeding populations. It is a prolific breeder, capable of tripling its population in 14-16 months. Females reach sexual maturity at 5-6 months of age, producing 2-3 litters per year of 4-8 piglets.

Distribution

Pigs were first introduced to North America from Europe around 1539, likely as semi-domestic livestock descended from Eurasian swine. Additional introductions of wild Eurasian boars from Europe and Asia for sport hunting occurred throughout the 1800s and 1900s. Over many decades, these diverse stocks have converged to form free-ranging feral hog populations which have quickly spread across the United States. Experts estimate current numbers at over 5 million animals nationwide. As of 2016, the feral hog has been reported from every Mid-Atlantic state, though no established populations occur in Maryland.

 

Note: Distribution data for this species may have changed since the publication of the Mid-Atlantic Field Guide to Aquatic Invasive Species (2016), the source of information for this description.

Environmental Impacts

The feral hog can be destructive to fields, fences, and other infrastructure, wetlands, and many wildlife species. Its wallows can affect ponds and wetlands, muddying the water and destroying aquatic vegetation. Its rooting behavior facilitates the invasion of noxious weeds and reduces diversity and distribution of native species. The feral hog can strip a field of crops in one night, and pose a predatory threat to ground nesting birds and other wildlife. It can also transmit diseases and parasites to wildlife, livestock, pets and humans.

Video
Note

Information for this species profile comes from the Mid-Atlantic Field Guide to Aquatic Invasive Species (2016).

Resident Canada Goose

Photo credit: Viktor Dahl, https://flic.kr/p/RV98Nv

(Branta canadensis)

Species at a Glance

The Canada goose in the Atlantic flyway population is comprised of two large subpopulations; a native population of migrant geese that overwinters in the Mid-Atlantic region, and an introduced population of non-migratory resident geese. The resident Canada goose is a product of intentional stocking and is now established throughout the Atlantic flyway states and southern Canada. Since its introduction, populations of the resident goose have increased dramatically, with numerous ecological, agricultural, and aesthetic impacts.

Identification

The Canada goose is a large waterfowl weighing up to 8 kg (18 lbs). It has a long neck, large body, large webbed feet, and a wide flat bill. Both sexes have a black head and neck with broad white cheek patches that extend from the throat to the rear of the eye. The breast, abdomen, and flanks are light gray to dark chocolate brown. The back and tail are usually dark brown to black with a white U-shaped band on the rump. It is often seen in flight moving in V-shaped flocks.

Similar Species

The cackling goose (Branta hutchinsii) was once considered the same species as the Canada goose; however, the cackling goose is much smaller and has a tiny, stubby, triangular bill. In addition, the greater white-fronted goose (Anser albifrons) has a brown, not black, neck and lacks the white cheeks and throat. The snow goose (Chen caerulescens) has an all-white head and body with black wing tips. The Atlantic brant (Branta bernicla) has a dark chest and the white is limited to the neck.

Habitat

A highly adaptable species, the resident Canada goose uses a variety of habitats including islands in rivers and lakes, marshes, reservoirs, golf courses, agricultural fields, and grassy fields near water. It thrives in typical suburban landscapes that provide food in the form of grassy open areas and ponds for water and roosting.

Spread

The resident Canada goose is highly mobile and able to fly long distances to find food and nesting areas. It is also very prolific. In contrast to the migrant Canada goose, the resident Canada goose has few natural predators and gosling production is not as impacted by spring weather conditions.

Distribution

Stocking and releases of the resident Canada goose began in the early 1900s. It now nests throughout the Atlantic flyway states and southern Canada. It typically moves south only when forced by snow and ice. The population of the resident Canada goose in the Atlantic flyway has increased dramatically in the last 40 years and now totals over 1 million.

Note: Distribution data for this species may have changed since the publication of the Mid-Atlantic Field Guide to Aquatic Invasive Species (2016), the source of information for this description.

Environmental Impacts

Grazing by the resident Canada goose, particularly during the growing season, can damage native vegetation and agricultural crops. In addition, goose droppings can impact water quality by adding excessive nutrients. The presence of goose feces in residential areas is not only a nuisance, but can damage property and pose a potential human health threat.

Video