Thousand Islands – Frontenac Arch is one of four ecoregions of the Mixedwood Plains. The Thousand Islands in the Saint Lawrence River have a distinctive flora and fauna and are a part of the biological corridor. The bedrock is mostly gneiss, granite and marble, more than a billion years old. The Frontenac terrain is the youngest of the Ontario portions of the arch, dated at 1.2 billion years old. These rocks were once part of a large mountain chain of the ancient supercontinent of Rodinia. There is also a meteor crater near Holleford, where the shield meets the limestone plains of southeastern Ontario. The area
North American river otter the same beaver lodge simultaneously on three separate occasions. The North American river otters may compete with the American mink ("Mustela vison") for resources. In Alaska, the two species living in marine environments indicate niche separation through resource partitioning, probably related to the swimming abilities of these mustelids. North American river otters consume an extensive assortment of fish species ranging in size from that impart sufficient caloric intake for a minute amount of energy expenditure. North American river otters generally feed on prey that is in larger supply and easier to catch. As a result, slow-swimming fish are consumed more