Moose - Habitat 

Regions

Moose utilize a vast array of habitats, sometimes considered generalists, and other times specialists. They also select for permanent (do not change over time) and non-permanent habitats. Some moose select permanent habitats such as riparian willow/poplar communities or high-elevation shrub/scrubland communities that do not experience succession to other vegetative species. Other habitats include boreal forest, mixed forest, large delta floodplains, tundra and subalpine shrub, and stream valleys.

Since the inception of moose study, moose have been known to occupy post-fire habitats. Several studies have documented marked increases in moose density post-wildfire. This is due to fire creating high-quality forage immediately post-fire. However, time after fire and before inhabiting is debatable and subject to a further investigation of soil type and vegetation type. Disturbance in general seems to be an attractant for moose as documented by Peek et al. (1976) in a study done in Minnesota where fire used to be prevalent, but logging has since taken over as the main disturbance. All disturbed areas seemed to have a great density of moose, similar to other post-fire habitats studied elsewhere.


Photo Credit: Charles Rondeau

While moose do tend to inhabit fire-prone areas, they also subsist in habitats with no fire or where fire is injurious to the habitat. Riparian areas and wet, dense conifer forests prove very useful for moose in terms of both food and cover. Shrub-dominated landscapes above the timberline are also important, particularly if dominated by different types of willow.

Moose also use aquatic habitats for forage from late spring to late summer/early autumn. The seasonal variability of use of aquatic habitat is due primarily to forage quality, rather than insect avoidance which some studies suggest. Peek et al. found that moose observed in Minnesota in water were either foraging or standing with their bodies exposed to insects, disproving the insect avoidance theory. MacCracken (1992) reported aquatic use all year round in Alaska, with peaks during the summer months. MacCracken also hypothesized that foraging in aquatic habitats is a more efficient means of attaining sufficient nutrients than land foraging.

Due to different nutritional and protection needs of male and female moose, they select for different habitats at different times. While both sexes select for the same habitat during the rut, females will select for more cover when caring for young, but males will select for more nutritious habitat regardless of predation risks at the same time.


Photo Credit: Lorelei Carroll

Home Range, Dispersal, and Migration

Moose are found only in the northern hemisphere. Limitations of dispersal in the north are determined by food and cover availability whereas climate is the main limitation in the southern range of their dispersal. They have one of the largest home ranges of all other herbivores. However, the size of the home range varies highly with the age and sex of the animal, season, habitat quality, and weather, but forage availability is the main factor. The estimated home range size in northwestern Minnesota was found to be 1.4 square miles whereas the home ranges in Alaska reached up to 100 square miles.

Migration occurs if the benefit of leaving is greater than the benefit of staying within an individual’s home range. Often times the purpose of migration is to place an animal into an optimal mating environment. Moose generally spend winters in a communal winter range and summers in a more secluded range. The distance between summer and winter ranges tends to be a function of habitat dispersion and type of terrain. In northwestern Minnesota the migration distances were found to be between 8.7 – 21.2 miles and in Alaska 9.9 – 57.8 miles. The specific timing of migration varies year to year and is heavily influenced by climate. Migratory moose will follow the same path for each migration session.

Diet

As discussed earlier, moose use both terrestrial and aquatic habitats for forage. Moose use aquatic vegetation as a means of acquiring sufficient sodium. The terrestrial diet of moose is variable due to seasonal availability but as a whole is considered browse, or woody plants. Many deciduous and coniferous tree and shrub species are consumed by moose throughout North America. Willow (Salix sp.) species are not only selected for but preferred (consumed at a greater proportion than their presence in a habitat) over other species. Paper birch (Betula papyrifera ) and aspen ( Populus sp.) species are a staple in the diet, neither preferred nor selected for but consumed based on availability. Mountain cranberry ( Viburnum edule ) is another palatable species that moose select for in a habitat, but is less prevalent. Overstories of spruce ( Picea sp.) and balsam fir ( Abies balsamia ) are often used in winter as well. In general, early succession vegetation is most often sought after, hence the fire and disturbed habitat selection.