In research published in Wildlife Society Bulletin, scientists suggest that a key factor in the Canada lynx being listed as threatened under the Endangered Species Act is the major decline of snowshoe hares. The loss of hares, the primary food of the lynx, in turn may be caused by coyote populations that have surged in the absence of wolves. Scientists call this a "trophic cascade" of impacts.
http://www.sciencedaily.com/releases/2011/08/110830144530.htm