how environmental factors affect the endangered animal?

Animal species already extinct or extirpated from Canada include black-footed ferret (extirpated, 1937), swift fox (extirpated), sea mink (extinct), GREAT AUK (extinct, 1844), Labrador duck (extinct, 1878), passenger pigeon (extinct, 1914), timber rattlesnake (extirpated, 1941), paddlefish (extirpated, 1800s), Banff longnose dace (extinct, 1986), gravel chub (extirpated, 1958), blue walleye (extinct, 1965) and longjaw cisco (extinct, 1975). A number of other animal species are on the brink of extinction.


The major factors involved in the disappearance or endangering of Canadian species have been exploitation (HUNTING, fishing, gathering of eggs or young), destruction of habitat and POLLUTION. Factors affecting the quality of the ENVIRONMENT and leading to a steady loss of habitat include decrease in FOREST cover (cutting exceeds reforestation in most provinces); lack of natural VEGETATION to control EROSION on stream banks and woodlots on many farms; AIR POLLUTION from acid and other toxic substances; and WATER POLLUTION by industry, individuals and municipalities.

人類不斷破壞生態環境。例如：破壞動物的棲息地。（過度砍樹木）