The ongoing study of wolves and moose in Isle Royale National Park has a long-term goal of understanding the role of wolves in this isolated and protected ecosystem. The National Park Service re-established a wolf population in 2018-2019 after the recent native population virtually died out from inbreeding, caused by dwindling ice formation on Lake Superior. Wolves have been shown to have a major influence on the population dynamics of moose as the two species fluctuate in a roughly inverse pattern, with historic peaks and troughs at intervals of more than two decades.