Canada goose Branta canadensis / Branta canadensis maxima

About this pest

  • Canada goose 1sq A Canada goose.
  • Canada goose 2sq Canada goose in flight.
  • Canada goose 6sq Canada goose adults and goslings.
  • Canada goose 4sq Flock of Canada geese grazing in farmland.
  • PestDetec pic needed Flock of geese flying in V formation.

KEY CLUES

Distinctive features: A very large, light brown goose with a black head and neck and a white ‘chin strap’ marking. Males and females are alike except females are smaller. Goslings are yellow when first hatched but turn grey as adult plumage begins to grow.

Size: Beak to tail length 850-950 mm, weight 4.5-5.5 kg.

Droppings: Cylindrical and up to 100 mm long.  Fresh droppings are greenish and coated with white nitrogenous deposits.

Footprints: Large, webbed foot, 100 mm long and 750 mm wide.

Kill signs: Not applicable (a herbivore)

Vegetation damage: Grazes pasture grasses.

Distribution: Throughout New Zealand but most numerous in the South Island. From lowland to alpine regions.  Commonly found in wetlands and riverbeds.

WHY ARE CANADA GEESE PESTS?

Ecological impacts

Within Pauatahunui Inlet, north of Wellington, high numbers of Canada geese within a small bird sanctuary are reported to alter the indigenous intertidal salt-marsh vegetation and foul the water. During the breeding season they also aggressively protect their nests and chase indigenous bird species away. In the South Island the species mostly breeds along riverbeds and adjacent to high country lakes and could potentially be affecting the health of indigenous riparian habitat, if present, through grazing and trampling.  Canada geese may contribute to the introduction of new weeds to riparian areas by transporting seeds in their droppings or caught on feathers.

Other impacts

Canada geese damage agricultural grasslands and may also damage crops such as turnips, cereal crops and peas, although this is not commonly reported. Several studies have tried to quantify the amount of pasture they eat, including one estimate that four geese ate the equivalent amount of grass as one stock unit. Damage to pasture is variable around the country and depends on the number of geese using the area, which may in turn vary according to weather and climate conditions.

It was mainly due to these impacts, that, in 2011, Canada goose was listed as an unprotected species in New Zealand, replacing its previous classification as a game bird managed by Fish and Game New Zealand.

The geese also foul pasture, and other areas, with droppings which may carry diseases such as avian influenza, campylobacter, Escherichia coli, and salmonella, some of which could be passed to stock (although this has not been proven). The species is also considered a very significant risk of bird-strike to planes taking off and landing at airports, particularly where they congregate in large numbers close to an airport.

Read more about Canada geese.

Droppings

  • Canada goose droppings 1 Canada goose droppings.
  • Canada goose droppings 4sq Canada goose dropping beside a pencil for size.
  • Canada goose droppings 3sq Old Canada goose droppings.
  • Canada goose droppings 2sq Canada goose droppings in long grass.
  • PestDetec pic needed Canada goose droppings can accumulate in large quantities where birds are numerous.

Separate

Canada geese produce very large droppings that can be up to 100 mm long. Droppings are cylindrical and five to eight times longer than wide. Fresh droppings are greenish and coated with white nitrogenous deposits. The light green of fresh droppings will darken over a few days and old weathered goose droppings can look tan and more fibrous.  The white layer weathers off. Because geese have a rudimentary digestive system, they eat often and expel undigested remains quickly. Adult geese produce 1/2 to 1½ kilos of droppings per day per bird. Sites where Canada geese are numerous can get covered in droppings, so that they appear clumped together. Pathways covered in droppings can be common beside lakes, rivers and estuaries.

Can be confused with:

Droppings of other large and moderately-large waterfowl and wetland birds such as swans, ducks (especially paradise ducks) and pūkeko. Pūkeko droppings are much smaller, drier and more fibrous in appearance. Black swan droppings tend to be larger, a bit longer and much fatter. Mallard droppings are smaller, often deposited in groups, and can also be so runny as to have little form. Paradise duck droppings look very similar but are smaller than Canada goose droppings.

Clumped

Canada goose droppings can appear clumped together at sites where the geese are so numerous that the ground gets covered in droppings. Canada geese produce very large droppings that can be up to 100 mm long in large quantities. Droppings are cylindrical and five to eight times longer than wide. Fresh droppings are greenish and coated with white nitrogenous deposits. The light green of fresh droppings will darken over a few days and old weathered goose droppings can look tan and more fibrous.  The white layer weathers off. Because geese have a rudimentary digestive system, they eat often and expel undigested remains quickly. Adult geese produce 1/2 to 1½ kilos of droppings per day per bird. Pathways covered in droppings can be common beside lakes, rivers and estuaries.

Can be confused with:

Droppings of other large and moderately-large waterfowl and wetland birds such as swans, ducks (especially paradise duck) and pūkeko. Pūkeko droppings are much smaller, drier and more fibrous in appearance.  Black swan droppings tend to be larger, a bit longer and much fatter. Mallard droppings are smaller, often deposited in groups, and can also be so runny as to have little form. Paradise duck droppings look very similar but are smaller than Canada goose droppings.

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Footprints and Tracks

  • Canada goose tracks 1 Canada goose footprints.
  • Canada goose tracks 3sq Canada goose footprints in mud.
  • PestDetec-image-needed.jpg The Canada goose has large, black, webbed feet.
  • Canada goose nest 3sq Eggs in Canada goose nest.
  • Canada goose nest 4sq Canada goose nest, with eggs (foreground).
  • Canada goose nest 1sq Eggs in Canada goose nest.
  • Canada goose nest 5sq Eggs in Canada goose nest.

Paws and feet

Canada geese have large, black webbed feet. Adult feet are about 100 mm long and 75 mm wide. The footprints will show three toes with webbing between the toes and nails at the end of each toe.

Can be confused with:

The footprints of other waterfowl with webbed feet, particularly large species such as mute swans, black swans and other geese such as greylag goose and Cape Barren goose. Duck footprints are also webbed but are smaller.

Dens and nests

Canada geese usually locate their nests on elevated areas near water such as streams, lakes, ponds. Nests usually have a good view so the nesting adult can see any predators approaching. The nest is sometimes simply a depression in the ground lined with down but is often built up with grasses, rushes, sticks and other material. Pairs will nest singly but are often in loose colonies. Five eggs are laid on average but up to 10 in a nest have been reported. Laying is generally during September to October in New Zealand. Canada geese usually lay one clutch of eggs but second clutches have been reported. The white eggs measure approximately 88 mm long by 58 mm in diameter and weigh approximately 200 g.

Can be confused with:

The nests of other large waterfowl species, especially other goose species. The eggs of black swans are much larger and a pale blue colour.

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Have a look at all of our tracks.

Vegetation Damage

  • PestDetec pic needed Canada goose damage to ground-level vegetation.

Understorey (less than 3m)

Canada geese eat only plants and often graze agricultural grasslands. They prefer short grasses, clover and other legumes but will also eat cereal crops. Their grazing can result in swards of very short grass where goose sign (feathers and droppings) will be obvious.

A researcher in Canada found that Canada geese are altering the floral composition of East Coast Vancouver Island estuaries with adverse effects on the estuary. Within Pauatahunui Inlet, north of Wellington, high numbers of Canada geese within a small bird sanctuary are reported to alter the indigenous intertidal salt-marsh vegetation.

Can be confused with:

Short grass can also result from grazing by other waterfowl such as mute swans, black swans, greylag goose, Cape Barren goose and ducks; and by stock such as sheep and goats. Look for other clues such as feathers, droppings and footprints.

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Browse all types of vegetation damage.

Kill Sign

Kill sign is not applicable because Canada geese are herbivores (eat plants only).

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Other Clues

  • Canada goose other 2 A Canada goose feather.

Distribution

The Canada goose population is approximately 60,000, of which two thirds is in the South island and one third in the North Island. Birds mainly breed in the high country east of the Southern Alps and migrate to lowland lakes after breeding. They are generally found in the vicinity of lakes and lagoons where there are adjacent pastoral grasslands. The largest population is found on Lake Ellesmere, Canterbury, where 10,000-15,000 birds overwinter.

Can be confused with:

The other goose species present in New Zealand (Cape Barren geese and greylag/feral geese) can occur in the same areas as Canada geese but are easy to distinguish because they look different.

Sound

Canada geese have a characteristic, loud honking call when disturbed or when flying – hence their alternative name, ‘honker’. Listen to audio recordings of their typical calls at New Zealand Birds Online.

Can be confused with:

Other geese species in New Zealand (the rare Cape Barren goose and the greylag/feral goose) have similar calls to Canada goose.

Body covering

Feathers can often be found where Canada geese occur; in abundance at some locations during moulting season. Feathers may be downy white (body), un-patterned brown (wing and tail) or dark brown (head). Feathers can be up to 360 mm long. The United States Fish and Wildlife Service has some photos of Canada goose feathers in their feather identification catalogue.

Can be confused with:

The feathers of Canada goose can be confused with the feathers of other waterfowl species, especially other goose species.

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Have a look at all our other clues.

MORE ABOUT CANADA GEESE

Origin

Canada geese are native to North America. They were first introduced to New Zealand in 1876 but did not establish until further introductions in 1905 and 1920. The species did well in the South Island but had died out in the North Island by the 1930s. Subsequent reintroductions to the North Island, which started in 1969, succeeded in establishing the species in several regions. Comparisons with North American birds indicate that the Canada geese in New Zealand are mainly the Branta canadensis maxima species.

Description

A very large, light brown goose with a black head and neck and a distinctive white ‘chin strap’ marking. Males and females are alike except females are smaller. Newly hatched goslings have yellowish-grey down which becomes greyer as the birds mature. Older goslings have grey down and feathers. Juveniles have similar, but duller, colouration to the adults.

Birds of this species are also called ‘honkers’, because of the distinctive honking call they make when disturbed and when flying.

Size and weight

Body length 850-950 mm, weight 4.5-5.5 kg.

Behaviour

Canada geese fly in classic v-formation, calling while they fly. In North America, the characteristic flights of migratory Canada geese signal the start of fall/autumn. In the South Island, most birds breed in the high country, east of the Southern Alps, and migrate to lowland lakes and estuaries in November-February to moult. However, in the North Island, populations appear more sedentary, staying within the same location year-round, probably due to milder climate together with year-round availability of pasture for foraging.

Canada geese find a mate in the second year of life, mostly forming life-long couples, although if one dies the other may find a new mate. The male bird is called a gander and the female bird a goose. Male Canada geese can be very aggressive during breeding season and will chase other birds, and sometimes humans out of their territory. The female incubates the eggs for 24-28 days, while the male remains nearby, and all goslings hatch at the same time.

As soon as the goslings hatch, they are immediately capable of walking, swimming and finding their own food (a diet similar to the adult geese). Parents are often seen leading their goslings in a line when walking or swimming, usually with one adult at the front and the other at the back. While protecting their goslings, parents will often hiss at nearby creatures to warn them off. If the threat remains or a gosling is seized, they will then violently chase them away by attacking with bites and slaps of the wings. The young geese can fly at approximately 60-70 days of age. Lifespan in the wild for those that survive to adulthood ranges from 10 to 24 years.

Diet

Canada geese are almost entirely herbivorous, feeding on short grasses and clover available in pasture. When in the water, the geese will eat seed heads of sedges and feed on submerged plants such as Elodea and Egeria.

Habitat

Canada geese are found around waterbodies, such as rivers, high country tarns and coastal estuaries, where there is adjacent pasture or grassland for foraging.

How to get rid of it

Canada geese are not protected in New Zealand and can be hunted at any time of the year, with no limits on the number killed. Organised culls to control populations are carried out during the moult when they cannot fly. The moult is generally during the summer months. At other times of the year, fixed wing aircraft and helicopters are used in combination to muster the geese so that they can be shot from either the ground or from the helicopter. A permit is required to carry a firearm to hunt them on conservation lands. Any humane method can be used but not poisoning.

FIND MORE INFORMATION IN:

Heather B.D., and Robertson H.A. (1996).  The field guide to the birds of New Zealand. Auckland, New Zealand, Viking, Penguin books Ltd.

Waikato Regional Council (2015). Canada goose Branta anadensis maxima. Retrieved (2017) from https://www.waikatoregion.govt.nz/services/regional-services/plant-and-animal-pests/animal-pests/canada-goose

White, E.G. (1986) Canada geese in New Zealand. Information Paper No. 4. Centre for Resource Management, Lincoln College, Lincoln, New Zealand.

Williams, M.J. (2013). Canada goose. In Miskelly C.M. (ed.) New Zealand Birds Online.  www.nzbirdsonline.org.nz

Spurr, E. B. and Coleman J.D. (2005). Review of Canada goose population trends, damage, and control in New Zealand. Landcare Research Science Series No. 30. Manaaki Whenua Press, Lincoln.