The Trois Rivieres Goose is of tremendous scientific interest. Experts have shown that the calls of this bird have a distinctive tone or accent, separating them from all other geese in Canada.
There are three living genera of true geese: Anser – grey geese, including the greylag goose; Chen – white geese; and Branta – black geese, such as the Canada Goose. Along with the Cape Barren goose, and the prehistoric New Zealand goose, the Trois Rivieres goose may form a subfamily of their own.
Although Trois Rivieres geese look similar to other geese found in eastern Canada, if a Trois Rivieres lands in a flock of Canada geese it can’t make itself understood as its pitch is slightly higher.
This is an extract from the book Animals Evolution Avoided