|
Meadow jumping mouse
Mass varies substantially with the season. Summer weights range
between 11.15 and 24.8 grams, averaging between 16 and 19 g. Prior
to hibernation, meadow jumping mice may attain weights up to, or
greater than, 35 g.
Meadow jumping mice are recognized for their extremely long tails
and long hind feet. Small and slender, they differ from woodland
jumping mice in that they do not have a white-tipped tail and are
generally duller in color. Adults have a dorsal dark or olive brown
band, which is paler in juveniles. The sides are a pale
yellowish-brown, with black hairs lining the flanks, and the
under parts are white or buffy-white. The tail is sparsely haired,
dark brown on top and yellow-white on the bottom, and exceeds the
body length. The pelage is short, thick, and predominantly coarse.
These mice undergo an annual molt that usually commences after
mid-June for adults or in August for the juveniles and lasts for
about three weeks. Meadow jumping mice have small and delicate
forelimbs with four toes on each foot. The hind limbs are longer and
have five toes. The feet have naked soles. The head is small,
narrow, and relatively high crowned. The nose is short and pointed.
These mice have large infraorbital foramen. Dental formula is 1/1,
0/0, 1/0, 3/3. Meadow jumping mice are the only mammal with eighteen
teeth. The upper jaw is characterized as follows: short, narrow, and
longitudinally grooved incisors; small cheek teeth; and a small
peg-like premoloar that generally precedes the molars. These mice
have 8 mammary glands, 4 inguinal, 1 pectoral, and 1 abdominal.
Females may sometimes be slightly larger and weigh more than males.
Reproduction
The breeding season of meadow jumping mice occurs shortly after
hibernation in late April or May. Males emerge from hibernation
slightly prior to females and are reproductively active when the
females emerge. Within two weeks after emergence, the majority of
females are pregnant and gestation begins. Gestation is usually
about 18 days, but may be longer for lactating females. A female may
have 2 to 3 litters in a year. The average litter size is 5.3,
though the number of young vary between 2-9. In the north, most
young are born and weaned between June and August. Small and
weighing about 0.8 g, the neonates are naked, pink, blind, clawless
and deaf, but squeak audibly at birth. In the first week, their ear
pinnae unfold, fur begins to cover their backs, and their claws
appear. They begin crawling between the first and second weeks, and
by the third week they can hop, creep, and hear. Their incisors have
erupted, and they have tawny coats. By the end of the fourth week,
the young have adult pelage, and open eyes. Weaned, they are
independent between the 28-33rd day. Those young females born during
the spring may reproduce after two months.
Behavior
Meadow jumping mice are solitary, but not aggressive toward others
of their kind. They are generally nocturnal (although occasionally
diurnal), and usually move in sequential short hops of about 1 to 6
inches or by crawling along vole runways or in the grass. They are
also great swimmers and diggers and can climb. These mice are
relatively nomadic, and may roam up to 1 km in search of moist
habitat. Summer nests are made of grass and are generally placed in
or under protective structures or underground. Hibernation nests are
made of grass and leaves and usually lie in burrows 1-3 ft. below
the ground. These animals begin to hibernate between late September
and early October. Hibernation is not believed to be synchronous,
but dependent upon fat reserves. Juveniles usually start hibernating
later than adults. While in torpor, body temperature may drop as low
as 2 degrees celsius. These mice reemerge in mid-late spring.
Food Habits
Meadow jumping mice primarily eat seeds, but also feed on berries,
fruit, and insects. Grasses may be cut in sections to reach the seed
heads. These mice may leave these piles of grass debris with rachis
and glumes on the surface. In the spring, one half of the diet may
consist of animal foods after emergence from hibernation. Especially
important are Lepidoptera larvae and beetles of the familia
Carabidae and Curculionidae. Later, seeds and endogene, a fungus,
make up a greater part of consumption. Weight generally increases
toward the beginning of the fall, especially two weeks before
hibernation begins, as sufficient accumulated fat is required for
hibernation.
In captivity they should be offered a complete diet of rodent lab blocks, and rat or mouse
mix, with bits of fruit or veggies regularly. Cheerios or wheat
bread are great treats, in small quantities. Do NOT feed chocolate,
fried foods, salted foods, candy or junk food! They may enjoy
crickets and mealworms if they are captive bred, never feed wild
insects as they may carry parasites. Vitamins, like Nutri-Cal are a good addition to their diet, and added calcium
during nursing and growth due to demands on their systems at those
times, but take care not to overdo it. Water bottles should be used
to proved constant, clean water. Ceramic or stoneware food dishes
work well for keeping seeds or fresh foods off the floor, and a wire
mesh hopper that allows them to eat the lab blocks through without
extra waste.
Back to
Pet Rats, Mice, Gerbils, Jirds, Voles,
Lemmings and other Rodents
Other rodent pages you might be interested in:
Orphaned babies
Tricks you can
teach your pet
|
