The passenger pigeon (Ecotopistes migratorius), so-called because of its wandering, unpredictable migratory behaviour, ranged in enormous flocks from Canada to Florida, probably accounting for more than a quarter of all birds in North America. As a metaphor for the environmental impact of colonial settlement in the sixteenth, and population explosion in the nineteenth century, its extinction has many lessons. When European settlers made first contact with North America, they encountered an environment teeming with wildlife of incredible abundance. The awesomeness of American nature in the eyes of travellers from the Old World is well represented in accounts from the sixteenth and seventeenth centuries.
Even before permanent settlement, the vast codfish shoals off Newfoundland were well-known to Europeans. By the 1630s French missionaries in Quebec were talking about une infinité de Tourtelles (turtle doves), feeding on wild raspberries, strawberries, acorns, grapes and the seeds of the forest – oak acorns, beech mast, red maple and American elm seeds, hazel and alder. The core range of the wild pigeon corresponded with the eastern and southern deciduous trees, and ultimately its fate was bound up with the fate of the forests.
more here.