More weekend reflections at: http://weekendreflection.blogspot.com/
Canada Geese, or Branta Canadensis, were introduced to the UK from North America and are now British residents all year round. The RSPB estimates there are 82,500 breeding pairs in the UK. The largest of the Branta goose family, the males and females look alike although the male is larger and more bulky.
The BBC Guide to Life the universe and everything (which is sadly being phased out due to the Conservative/Tory government cuts) states:
"The UK bird is essentially different from the American bird. It has changed its behaviour, character, and build. Since its introduction it has largely become non-migratory, unlike the Anser genus in general. It is often to be found flitting between one local park and another. To give an example, the St James's Park, London, residents roost at Regent's Park lake each evening, and then spend the daylight hours back at St James's Park.
British Canada geese are generally heavier than the nominative race, and appear less prone to flight. This may be due to wing-clipping causing a reduction in the desire to fly. This does need some scientific study though, and is purely an educated guess on the part of birders in general. Certainly it is rare to find a Canada goose migrating to, or even more importantly from, Canada!
They are also far less aggressive as they have become more domesticated and familiar with humankind, so the aggressive streak found in native birds is reduced, but not gone, in native UK birds".