An Animal of the High Desert - Northern Grasshopper Mouse

Dr. Lloyd Glenn Ingles  California Academy of Sciences

The Northern Grasshopper Mouse (Onychomys leucogaster) is a rodent about the size of a small hamster with grayish fur on his back and white fur on its belly.  It has a short tail, about a third as long as the rest of its body.  Grasshopper mice are found in arid and semiarid regions from Mexico through central and western United States and into Canada.

As their name suggests, grasshopper mice eat grasshoppers.  They also eat other insects, lizards, spiders, and even other mice.  This mouse is more carnivorous than other mice.  In fact, about 90 percent of what they eat is animal material. They are aggressive predators.  They will stalk their prey, grasp it with their unusually long claws, and kill with a bite of their long, sharp teeth at the base of the prey's neck. They have enlarged jaw muscles for biting and chewing. They get most of the water they need from eating animal tissue.

Grasshopper mice are very territorial.  They have large territories (about six acres) that they mark with scent glands.  They may emit a shrill whistle to warn others from entering their territory.  Sometimes they will stand on their hind legs, throw their head back and "howl," much like a wolf.  The shrill, eerie call is audible to human ears for 100 yards or more.

Unlike most rodents, male and female grasshopper mice cooperate to raise their young. This may be because, like all predators, the young mice need to be taught how to hunt and kill prey.

Because of their strong, social bonds, their aggressive hunting skills and their territorial behavior, these small rodents are often compared to a wolf. 

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