Though moose are not commonly thought of as migratory, some populations have individuals that migrate more than 100 km between summer and winter ranges. In north-central Alaska, which includes Gates of the Arctic National Park and Preserve, Kanuti National Wildlife Refuge, and a mix of other federal, state, and private lands, moose migrate approximately 30 km between summer and winter ranges. Moose migrate in every direction, rather than a north to south movement that may be expected for this highly seasonal, Arctic environment. Indeed, in most of the fall migrations, moose move north for the winter. The durations of fall and spring migrations are very similar, 18-19 days long. Their seasonal migrations may be related to habitat preferences, snow conditions, elevation, and terrain. Bull moose exhibited a greater propensity to migrate than females. Compared to populations in other parts of central Alaska, fewer moose are migratory and individuals migrate shorter distances. Researchers are still working to understand these differences, but one explanation could be related to population density. In this region, moose densities tend to be low (0.1 moose/km2).