Nutrition
Reindeer are herbivores that consume most of their diet by
grazing, and eat up to 12 pounds of food a day.
In the winter months, 90% of the reindeer's diet is constituted of
lichens, specifically Cladonia rangiferina (reindeer
lichen) .
Other species such as C. arbuscula (shrubby or tree reindeer
lichen), C. mitis (green or yellow reindeer lichen), and C. stellaris
(star or star-tipped

Reindeer store their food as fat, which they use as a
reserve in the winter months to conserve energy when food is scarce.
Because they are ruminants, they possess a four-chambered stomach for
digestion of food. The reticulum,
rumen, and omasum are the primary compartments for digestion before food enters
the stomach (abomasum). These
compartments allow the reindeer to digest vegetation that humans cannot. The
reticulum collects foreign objects and also moves ingested food into the
subsequent compartments. The rumen
is the large "fermentation vat" that contains millions of bacteria.
These bacteria secrete enzymes that have the ability to degrade
cellulose. The rumen also absorbs
fatty acid by-products of digestion.
The omasum helps to grind food, and also removes liquid from ingested roughage.
Lastly, the abomasum is the site of gastric secretion that digests food and
specifically carbohydrates, and it contains a low pH that
breaks down protein
and kills any bacteria that may be present.18
Learn about the
life history of reindeer from young to old
next! 
