Canada geese are one of the more detectable pest animals in New Zealand.
Even when out of sight, their honking call is distinctive.
The birds themselves are a common sight in many parts of the country, as they feed during daylight in open areas. In comparison, many of our other pest species are much less visible, being nocturnal, well camouflaged and/or secretive in their behaviour.
Canada geese are easily recognised for their large size. Adults measure 850 to 950 mm in beak-to-tail length.
Their black head and neck plumage with white ‘chin strap’ marking is also distinctive. The droppings, too, are noticeable – cylindrical pellets up to 100mm long and, when fresh, greenish in colour with white deposits.
Flocks often leave large volumes of these droppings, which can foul pasture and urban amenity areas. While Canada geese breed, and are often seen, in solitary pairs, they can nest close together and congregate in large numbers. It is when they are in flocks that their negative impacts are most pronounced. They can foul water, damage agricultural grasslands and other crops and it is thought likely that their trampling and grazing damages riparian habitats. Their aggressive behaviour during breeding season can scare away native birds and large flocks near airports can pose a risk of bird strike.
Organised culls to control populations are periodically carried out during the summer moult when the birds cannot fly. Canada geese used to be managed as game birds but are no longer protected in New Zealand and can be hunted at any time of the year, with no limits on the number killed.
See more about Canada geese on our culprit page.
Listen to audio recordings of their typical calls at New Zealand Birds Online.
Photograph: by Andrew Walmsley