is much too cold for trees to grow in Aulavik. So, too, with spiders and insects – they simply cannot survive in the severe climate of this region.

The species that exist in our National Parks cover the range of living organisms – from the microscopic bacteria that help fallen leaves decompose and enrich the soil, to plant-fertilizing insects, to ivory-tusked narwhals that navigate the cold waters of the Arctic in close-knit groups of 15 to 20.

The abundance of terrestrial and marine life in the many ecosystems of the National Parks is staggering, but it can never be taken for granted. The Dawson caribou, for example – one of 11 species of mammals native to the region in which Gwaii Haanas National Park Reserve, on the Pacific Coast, is located – was overhunted and became completely extinct by the turn of the twentieth century. Other species, though still in existence, have been extirpated; that is, they have disappeared from habitats

once native to them. Greater prairie chickens and black-footed ferrets, for instance, no longer roam the dry hills and eroded river valleys of Grasslands National Park, in southern Saskatchewan. The population of this ferret is estimated to have been between 500,000 and one million in 1900. Today, under 500 survive, a result of the loss of most of the animal’s grassland habitat to agriculture and the drastic reduction through poisoning of the population of prairie dogs on which the black-footed ferret fed.