Roosevelt Elk

Herbivory in action

The Roosevelt elk are strictly herbivores with a digestive system that can handle many of the grasses and vegetation that is commonly found in its habitat. The habitat that the elk resides in is mainly the pacific rain forests but there can be many other places it can be found where in every winter is a lack of vegetation. It has been observed that during the winter the elk don’t eat when there is snow on the ground, but that once the snow has melted the elk eat exclusively until either they run out of food or there is once again a layer of snow. This can cause some problems with the elk and in some instances the elk can go hungry in the winter months for prolong periods of time(Murie 1951).

The elk has adaptations that help it acquire its food. These adaptations include the well-developed digestive system that includes 4 stomachs and a long intestinal tract that allow it to absorb as many nutrients that it can while it still has the organic material in its body. These nutrients help it fuel its body and fight the sometimes bitterly cold temperature, with the help of its thick winter coat as well. After the nutrients are digested they continue into the closed circulatory system that Roosevelt elk have. This allows the elk to move faster than organisms with an open circulatory system and also allows them to regulate their bodies with more control than organisms with an open circulatory system.

The elk stores excess food as fat. They tap into the fat stores during winter when there is not enough food to survive off of. This causes some problems during after the rut when some bulls are not able to survive because their long term fat stores were diminished because of the mating season. There have been some bulls that have died in the winter because of diminished fats reserves and lack of food.

When the elk does have food available here are some common types of vegetation their diet consists of (Murie 1951):

Genus: Acer (Maple trees): This is a common plant that is consumed by the Roosevelt elk. These trees and shrubs are found in extensively in the Olympic Mountains. The elk feed off of the leaves that these plants produce. This is one of the major food sources for the elk because they are plentiful within their habitat and readily accessible. Another advantage is the elk cannot reach the hind limbs so the tree will never be killed because of the feeding of elk. During some heavy snow falls the limbs that are usually out of reach for the elk can be bent downwards so as they become available for the elk to feed off of. The major problem with Maple trees is that the elk can become injured when eating if a splinter is lodged in its tongue. Usually in the winter the elk will eat the twigs of the maple, but in the spring and summer it will eat the leaves of the trees. Also during large storms the limbs of trees will periodically fall down. When a limb falls down the limb is stripped of all of its bark and twigs by the Roosevelt elk. The stomach of a Roosevelt elk was opened to reveal the contents being 99% vine maple mixed with big leaf maple(Murie 1951).This only shows how dependent on different types of maples the Roosevelt elk is.

Alnus rubia (Red Alder): This is a plant that is mainly consumed in the winter(Harper 1967). Usually the elk will strip the bark and twigs off of the limbs much like it did with the maple. In the spring the elk will mainly devour the leaves of the tree with the twigs being saved once the leaves are gone.

Gaultheria shallon (Salal): Most of the Salal is unevenly distributed throughout most of the habitats the Roosevelt elk primarily lives in(Murie 1951). Although this is the case, sometimes when present the Salal is abundant in these habitats. The elk eats mainly eats the leaves of this shrub. This is not a major food that the elk eats but it is commonly found within the stomach of the elk.

Pseudotsuga taxifolia (Douglas-fir): This is one of the more attractive foods that the elk has access to. This is not readily available to the elk so there are some complications that arise when comparing it to the amount that an elk will actually eat(Murie 1951). This is still a popular food item when the elk has this present; it will devour all of the Douglas-fir it can find.

Rubus macropetalus (Blackberry): On the Blackberry, mostly the twigs and vine are consumed. Although they are commonly found in the Olympic Peninsula a large herd of elk that once lived there no longer browses the setting(Murie 1951). The vines of the blackberry are also eaten in the California region that the Roosevelt elk resides in.

Vacinium. Blueberry: There are four different species of blueberry that are commonly eaten by the elk: Vacinium parvifolium, Vacinium ovalifolium, Actinium membranceum, Vacinium ovatum(Murie 1951). Some of these berries are actually abundant during the winter. These are thought to be the most appealing vegetation that the elk consistently eats. There have been some plants that have died because there had been too much feeding per plant that there were not enough leaves to continue making energy through photosynthesis.

Mushrooms: The Roosevelt elk have been documented to have been eating different types of mushrooms(Murie 1951) These mushrooms were never identified so the specific species of mushroom remains unknown but it is still interesting that the elk have used mushrooms as a food source.

Rotten Wood: Yes, evidence has led to the conclusion that Roosevelt elk do eat rotten wood. The main types of wood that they eat are: Hemlock and maple. To actually eat the wood the elk would dig a small tunnel below the wood and actually eat the wood from the bottom up. The reason why the elk prefers to eat the underside of rotten wood and also why they eat rotten wood are both unknown. The actual nutritional contents of rotten wood are not considerably large although there are still some concentrations of nutrients available(Murie 1951).

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