The Canada goose (Branta canadensis) is not native to the United Kingdom. They were first introduced in the late 17th century as an ornamental attraction to parks and the gardens of stately homes. Although originally restricted to a few areas, in the 1950s and 60s they spread to many other habitats. The numerous flooded mineral extraction pits and lakes around the country provide ideal environments for the geese. A recent estimate of the UK population suggests a figure exceeding 100,000 individuals (BASC, 2011).
Canada geese tend to be traditional in their choice of breeding site and females generally return to their natal area to nest year after year, irrespective of whether or not breeding in previous seasons has been successful. Canada geese may breed from 2-3 years of age. In the UK egg-laying starts in the second half of March with the main period in the first half of April. The nest is typically located on the ground and close to water and often in the shelter of a bush or at the base of tree. The nest will invariably be on an island if these are present at the breeding site. Most lay a clutch, which varies in size from 3-11 eggs. In April 2004, an incredible 22 eggs were found in one nest on an island on the River Thames. It is unlikely that all would have survived and most probable that more than one bird had laid the eggs. Incubation is undertaken by the female and lasts for about 30 days. Overall the breeding success of Canada geese is relatively good. During the winter the species is believed to be more mobile and may range over several kilometres from lakes to feed in pastures and fields of winter cereals.
Increased numbers already cause problems in many areas. They damage not only growing crops, but also amenity land in urban parks, open spaces, golf courses and grassed areas around rivers, lakes and ponds leading to bank erosion. They are often responsible for extensive fouling of lawns and other grassy areas, footpaths and lakes causing an unpleasant nuisance. During the nesting season they can act defensively towards humans if threatened. A large flock, defecating every few minutes, can deposit a great deal of excreta. Recent studies have shown that Canada goose droppings contain pathogenic bacteria that are potentially harmful to man. Increasingly flocks are being involved in collisions with aircraft. This includes both fixed wing and rotary winged craft. In 1995 a large flock was responsible for bringing down a military surveillance aircraft in Alaska killing the entire crew. In January 2009 the pilot of a US Airways jet ditched his stricken plane into the icy waters of the Hudson River moments after taking off from New York’s LaGuardia Airport having struck a flock of Canada geese. In this instance the pilot managed to avoid disaster and saved the lives of all 155 people on board.
The need for financial investment and optimum timing is accepted for the control of other pests and Canada goose control should be regarded in the same way. It must be borne in mind that control may have to be carried out over a period of years to be effective. Control measures will vary according to the site concerned, whether it is located in an urban or rural area, the number of birds present and the proximity to other populations. Control measures must be undertaken as humanely as possible. In urban areas especially the potential for public objection can be high. Non professional management should therefore not be considered as this only enhances the very real risk of adverse publicity.