The meadow jumping mouse (Zapus hudsonius) is the most widely distributed mouse in the family Zapodidae. Its range extends from the Atlantic coast in the east to the Great Plains west, and from the arctic tree lines in Canada and Alaska to the north, and Georgia, Alabama, Arizona, and New Mexico to the south. In mid-2014, the New Mexico subspecies of the meadow jumping mouse, Zapus hudsonius luteus, was listed as an endangered species under the federal Endangered Species Act.
Description
The meadow jumping mouse can range in length, from 180 mm to 240 mm, with its tail taking credit for most of its length, usually about 108 mm to 165 mm. A distinct characteristic about this species is its enlarged hind feet, which can be 28 to 35 mm long, and relatively short forelimbs. This gives it a kangaroo rat-like look, although its tail shows that it is not a kangaroo rat because it is not bushy at the tip. The pelage of this creature is short, and with somewhat dense, coarse hair. The color of the pelage has a few variations, but a broad dorsal stripe is always present. This broad dorsal stripe is of a darker brown color, with black tips, giving it a somewhat a grayish appearance. The sides are usually a lighter color, usually bright yellow to orange, and the under body is usually white, matching the color of its feet. These mice have eight mammary glands, four inguinal, two pectoral, and two abdominal. The male genitalia are inconspicuous except during mating season when the scrotal sac becomes enlarged and more visible. The tail (which again makes up most of this creature's body length) is bicolored, showing a darker color from above and a lighter color below. It is lightly covered with hair, which gets longer as it approaches the tip, but does not get bushy like the kangaroo rat. Its ears are very noticeable, and its whiskers are prominent. The head is small, and narrow, and it is considered to be relatively high crowned. The nose is short, yet it is pointy, and the eyes are relatively big. These mice also have a large infraorbital foramen. With the exception of the Aye-Aye, the meadow jumping mouse is the only mammal to have eighteen teeth with a dental formula of: 1/1, 0/0, 1/0, and 3/3. The upper jaw is short, and narrow. The incisors are longitudinally grooved, and its cheek teeth are small. Preceding the molars is a small peg-like premolar. As a whole the female jumping mouse is slightly larger, and heavier than the male, but their weight varies quite a bit depending on the season. Their weight during summer seasons can range from 11.15 grams to 24. 8 grams, with an average at about 16 to 19 grams. Just prior to hibernation, jumping mice can obtain a weight of 35 grams or larger.
Habitat
Meadow jumping mice prefer a habitat which is high in humidity. Although they may live in many different areas usually with high herbaceous cover, they prefer moist grasslands, and avoid heavily wooded areas. High numbers are usually found in grassy fields, and thick vegetated areas with streams, ponds, or marshes nearby. They prefer large open areas to thickly wooded areas. As was stated before they are found in large parts of the United States, and up to Canada.
Behavior
The most interesting characteristic of the meadow jumping mouse is its saltatorial powers. Quimby states that there is large disagreement, dating back to 1899, as to how high the jumping mouse can actually jump. In 1899 Preble documented that the meadow jumping mouse can jump six to eight feet when disturbed, and in some instances it may be able to jump further. Then in 1909 Seton stated that it can creep through the grass without hopping, and then suddenly can leap out a distance of ten to twelve feet. Later in 1926 Bailey says that there are no standards as to how long or far Z. hudsonius can leap. He states that it is capable of long leaps, short hops, and also it can creep through the grass on all fours without having to leap at all and without any difficulty at all. Finally in 1935, Townsend was able to witness a leap of two feet, and many more studies afterwards and to the date have concluded that the meadow jumping mouse is capable of jumping anywhere from two to three feet depending on the situation. Under certain lab-controlled conditions, the jumping mouse has been measured to jump a few inches longer than three feet. What is clear is that the meadow jumping mouse is capable of leaping a good sized distance compared to its body size. The initial leap of the jumping mouse when startled from a squatting position is long; the following hops are shorter but much more rapid. When not alarmed the normal locomotion method is little hops of one to six inches.