Lifestyle and Habits
Last Review/Updated: May 31, 2002
Large Rodents
Of
the 37 species of rodents in Alberta, only a few are regularly seen
by people. Most are active at night (nocturnal) and secretive in behavior.
Of the large rodents featured here, marmots are active during the day
(diurnal); and the beaver, muskrat and porcupine are generally nocturnal.
The marmots (Genus Marmot) are large members of the squirrel family (Sciuridae). Marmots hibernate during the winter. Hibernation is an adaptation to the cold of winter, when an animal enters a dormant state. In this sleeplike condition, the animal's body temperature, heart beat rate and energy requirements are reduced. Before entering hibernation in the fall, marmots store food energy in the form of body fat. This fat supplies the animal with all the energy it needs to stay alive until spring.
Beaver,
muskrat and porcupine do not hibernate. They remain active throughout
the winter and must continually find enough food to supply their high
energy requirements during the cold winter months.
The beaver is one of the few animals that changes its environment to suit its lifestyle. Beavers construct dams on streams to create ponds. The pond provides protection for the beaver family. A beaver house is constructed of sticks and mud, and is usually situated well away from shore so that landbased predators cannot get at it in summer. In winter, the mud freezes, forming an impregnable fortress against predators that might venture across the ice. Beavers eat the bark of trees and shrubs. The beaver pond floods the surrounding woodland, allowing the beavers to fell trees close to shore. Beavers may raise the height of the dam so that they can bring more food into reach. When the food supply is finally exhausted at the dam's maximum height, the beaver family abandons the pond and moves to another site. Some beavers live along rivers and do not build dams or lodges. Instead they burrow into the bank of the river and fell trees for food near their home.
The
muskrat also lives in ponds, but it does not build dams. Muskrat houses
are built with mud, pond weeds and cattail stalks. In the winter, muskrats
form "push-ups" in the pond ice over their feeding areas. Push-ups
are domes of frozen vegetation covering a hole in the ice. The muskrat
keeps these holes open throughout the winter by continually chewing
away the ice and pulling up underwater vegetation to build an insulated
dome over the hole.
Porcupines move about at a slow and plodding pace, and are easily overtaken by most animals. However, their impressive defense system discourages attack by wolves, coyotes or other predators. A porcupine will turn its tail to an attacker and cover its unprotected face. If the attacker gets too close, the porcupine will lash out with its spiny, clublike tail. The blows from the tail are delivered swiftly, and the loose quills are easily detached from the porcupine's skin.
The barbed quills can be quite painful and prevent the attacker from feeding, especially if they are impaled in the mouth or paws. The barbs on the quills prevent easy removal and promote movement deeper into the victim. Thus, the quills can kill an animal weeks after an attack.
Lagomorphs
Lagomorphs are divided into two families, Leporidae (rabbits and hares) and Ochotonidae (pikas). Rabbits and hares are the best known group, having the characteristic long ears and hind legs. Hares are generally longer-legged and larger-eared than rabbits.
Hares
differ from rabbits also in the way they raise their young. Hares only
scrape out a depression on top of the ground for a nest. Young are
born fully furred, with eyes open (precocial young). They are able
to move about soon after birth. On the other hand, young rabbits are
born in an underground nest, naked, with eyes closed (altricial young).
Altricial young require more care from the adults.
The snowshoe hare and the white-tailed jack rabbit are the two species of hare, and the cottontail is the only species of wild rabbit found in Alberta. Rabbits and hares are mainly nocturnal in their habits.
Pikas look more like guinea pigs than rabbits or hares. Yet, they have the same tooth and skull structure as the latter, which places them firmly in the Order Lagomorpha. Pikas have short, rounded ears, and short legs. They are diurnal in activity and can often be seen in an alpine rock slide.
Lagomorphs do not hibernate, and must spend the winter searching for food. The pika is the only lagomorph to store food in the summer for use in the winter.
