Canada goose Branta canadensis maxima
Why Canada Goose are a potential nuisance animal
|Production threat||Environmental threat||Public threat|
The Canada goose, native to arctic and temperate areas of North America, was introduced to New Zealand in 1905 and 1920 but did not become established in the North Island until it was re-released in the 1970s. The introductions were from uncertain sources, and probably of mixed stock, but comparisons with North American birds indicate the New Zealand stock is mainly the Branta canadensis maxima species.
These geese are widely distributed throughout the Waikato, with flocks reported most frequently on coastal farms from Kawhia Harbour to Port Waikato and wetland areas in the Waikato and Hauraki districts. They have also been reported by landowners at some sites on the Coromandel Peninsula.
While largely herbivorous, eating a wide range of grasses and grains, the Canada goose also consumes small fish and insects. Its impact on farm production is largely unquantified, but it is known that five geese may consume the same amount of grass as one sheep and that they impact on production by fouling paddocks.
In the water, these geese feed from bottom sediments and also directly on aquatic plants. However, defecation from large numbers of Canada goose is the greater threat to aquatic values. When these geese concentrate at specific sites, their droppings introduce bacteria and nutrients into waterways. The Canada goose also competes with other waterfowl for wetland resources.
- Body length ranges between 75 to 110cm.
- Wingspan ranges between 127 to 183cm.
- Black head and neck.
- Face has distinctive white patches, sometimes referred to as ‘chin straps’.
- Brown and grey plumage.
- Males weigh up to 6.5kg and females 5.5kg.
- An average nest contains five eggs.
Responsibility for control
Landowners/occupiers in the Waikato who wish to, may control Canada goose on their property at any time.
The Canada goose is not recognised as a pest by Waikato Regional Council.
In June 2011 the Canada goose was moved from schedule 1 of the Wildlife Act 1953 to schedule 5. This means this species is no longer recognised as a game bird, and that Fish & Game councils no longer have any legal responsibility for its management.
Therefore all landowners/occupiers in the Waikato who wish to may control Canada goose on their properties. Control can be done at any time, by any humane means, although no poisons have been registered for goose control.
How to control canada goose
The best control occurs where these geese are targeted across the entire area or ‘range’ they inhabit and move between. For example, a ‘range’ may include a harbour, lake and waterway.
Piecemeal attempts to control Canada goose on one property usually result in them seeking a less disturbed location on another property. Repeated isolated control attempts can lead to birds becoming wary and more difficult to control, and usually have little impact on the population.
Collaboration between all affected landowners is key. Coordinated control has the greatest chance of success in reducing populations. Consult with your neighbours and develop a coordinated control plan.
Scaring or environmental modification
Scaring devices such as LPG cannons, water sprinklers or plastic shopping bags on electric fence standards only work for a short time. The birds can become habituated to the device.
Environmental modification with fencing, rocky shorelines hindering access, and long grass or shrubby vegetation make the environment unwelcome for the Canada goose. These methods cause the geese to seek less disturbed locations elsewhere.
Crushing eggs is not recommended and will cause the geese to find a more secure or isolated location to re-lay, which may be harder to find.
Oiling, pricking or addling (shaking) leaves infertile eggs that the geese will attempt to incubate unsuccessfully. The average nest contains five eggs. To impact the population, over half of the eggs laid each year will need to be interfered with, on an ongoing basis. The population may not decrease right away, but natural mortality will reduce it over time. This technique is often employed to supplement other control techniques.
Usually in January or February, the Canada goose loses its primary and secondary wing feathers and become flightless for up to three weeks. During this time they congregate on safe water bodies as a resting place. They depend on available food sources which they frequently overgraze and destroy.
Culling involves herding them off the water along hessian or shade cloth fencing, and funnelling them into pens to be humanely euthanised.
It is important to attempt to capture all flightless individuals in a moult cull. Any which escape may become wary and more difficult to cull the following season, and may also seek new moult sites.
Consider using discreet locations for culls and disposal of carcasses. Well run moult culls significantly reduce Canada goose populations.
Disciplined, coordinated hunting will reduce populations.
Small scale hunts with bags in single digits, potshots using high powered rifles, and scaring through the use of firearms from farm vehicles do not have any meaningful impact on a large population. This can create wary more difficult to hunt birds, and undermine coordinated hunting attempts. Therefore, this approach is discouraged.
Coordinated landscape hunting involves the use of shotguns in hides or reclining blinds at feed sites. The Canada goose move from their roost site at daybreak and head to their feed sites. They may travel between these two sites, or other feed sites, multiple times during the day. At dusk they return to their roost site.
Good reconnaissance is needed to identify feed sites and target all feed sites. The hides or blinds should be set up downwind of the feed site. Decoys can also be used. Depending on Canada goose numbers, two to five hunters are normally needed at each feed site, and remain there all day.
For best results, develop contacts with experienced hunters. Your local Fish & Game branch may be able to assist. Try to build experience by involving the same hunters each year. Again, depending on the population, this technique can significantly reduce Canada goose populations.
For advice and additional information on control methods, call our animal pest staff on freephone 0800 BIOSEC (0800 246 732).