Jumping mice can easily be distinguished from all other mice in Great Smoky Mountains National Park by their long hind legs, large hind feet, and a tail that is considerably longer than the body. This species occurs in localized populations at all elevations in the park. It has been taken in deciduous as well as spruce-fir forests. The woodland jumping mouse is primarily nocturnal and is active only during the warmer months. The period from about October to May is spent hibernating in a nest in a subterranean burrow. The most interesting aspect of the food habits of Napaeozapus is their apparent dependence on the fungus Endogone as a food source.

Species Measurements:
- Adult Total Length: 210-250 mm (8?-9? in.)
- Tail: 125-150 mm (4 4/5-5 4/5 in.)
- Hind Foot: 29-35 mm (1⅛-1⅜ in.)
- Weight: 21-28 g (?-1 oz.)

Physical Characteristics:
Jumping mice can easily be distinguished from all other mice in Great Smoky Mountains National Park by their long hind legs, large hind feet, and a tail that is considerably longer than the body. In addition, the deep orange or yellow upper incisors are deeply grooved on their anterior surface.
The medium-sized woodland jumping mouse has bright orange-brown sides, a dark median dorsal band, and white underparts. The long, bicolored tail usually ends in a white tip, unlike the dark tip of the meadow jumping mouse.

Habitat:
The woodland jumping mouse occurs in localized populations at all elevations in the park. It inhabits deciduous as well as spruce-fir forests. The rhododendron-covered shores of mountain streams provide excellent habitat. Some individuals, however, have been taken near streams in dense woods with little or no underbrush.

Reproduction:
Breeding extends from May to August with peak litter production in June. One to two litters averaging four to five young are produced annually. Nursing (or lactating) females, females with placental scars, or females with embryos have been recorded on the following dates: June 29 (lactating); July 4 (lactating); July 5 (placental scars 1R, 3L); July 10 (5 embryos-7 mm); July 11 (7 embryos); July 17 (placental scars 0R, 3L; nursing); August 28 (lactating); August 31 (placental scars 3R, 1L; nursing); and September 10 (lactating). Males in breeding condition have been noted in June (3), July (1), and August (3). Immature mice have been recorded in June (2) and September (3).

Longevity:
Some wild individuals live as long as three or four years (Linzey, 1995a).

Terrestrial Ecology:
The woodland jumping mouse is primarily nocturnal and is active only during the warmer months. The period from about October to May is spent hibernating in a nest in a subterranean burrow. Active individuals have been observed as late as November 27, 1934 along Cosby Creek (2,500 feet) and as early as February 2, 1964, near park headquarters (Linzey, 1995a). Large fat reserves are a source of energy during hibernation.

Feeding Habits:
Seeds, fungi, fruits, and insects constitute the primary food. Whitaker (1962) examined a single Napaeozapus taken at Indian Gap (Sevier County) in June, 1930, and noted that 50% of the food was composed of the fungus Endogone. The stomachs of 16 jumping mice captured near the Cosby Ranger Station (Cocke County) during summer and two individuals taken along the Appalachian Trail near Low Gap during July were examined by Linzey and Linzey, 1973. The most interesting aspect of the food habits of Napaeozapus is their apparent dependence on the fungus Endogone as a food source. Seventy-eight percent of the animals examined by Linzey contained Endogone spores, which amounted to almost 40% of the total food volume. Although Endogone was recorded in two shrews and six other species of mice, only in two of these species (Blarina, 4.9%; Peromyscus leucopus, 4.2%) did it comprise more than 4.0% of the total volume of food. In the rest, Endogone never amounted to more than 1.0% of the total food volume. Plant materials formed approximately 76% of the total volume, while animal foods comprised 21.5% of the total food volume. Lepidoptera larvae comprised over half of the animal food (11.6%). The diet of the two individuals from the Appalachian Trail was markedly different from that of the Cosby specimens. These mice were feeding primarily upon seeds (volume 89.5%), while insect remains accounted for only 1.5% of the total volume. Endogone was absent.

Predators and Defense:
Timber rattlesnakes (Crotalus horridus) taken near the Tremont CCC Camp (3,200 feet), along Kephart Prong (3,000 feet), and along the Little River above Elkmont had eaten these mice (Linzey, 1995a). Savage (1967) removed specimens from nine other timber rattlesnakes. In October, 1950, a woodland jumping mouse was removed from the stomach of a screech owl (Otus asio) found near Smokemont (Stupka, 1950). Six woodland jumping mice were found in the stomach of a bobcat (Lynx rufus) found dead on the Newfound Gap Road in Tennessee in August, 1952 (Stupka, 1952).

Parasites:
Pfitzer (1950) removed two fleas (Epitedia sp. and Ctenophthalmus sp.) from a male woodland jumping mouse. Linzey (1995b) removed mites (unidentified) from three males.

The woodland jumping mouse is found from Labrador, Quebec, and New Brunswick, west to southeastern Manitoba, Canada, and south in the Appalachian Mountains to eastern Kentucky and northern Georgia.

This species occurs in localized populations at all elevations. It has been taken in deciduous as well as spruce-fir forests. Many individuals have been captured along the rhododendron-covered shores of mountain streams; others, however, have been taken near streams in dense woods with little or no underbrush.

References:

Linzey, D. W. 1995a. Mammals of Great Smoky Mountains National Park. The McDonald & Woodward Publishing Company, Inc., Blacksburg, Virginia.

Linzey, D. W. 1995b. Mammals of Great Smoky Mountains National Park-1995 Update. Journal of the Elisha Mitchell Scientific Society 111(1): 1-81.

Linzey, D. W. 1998. The Mammals of Virginia. The McDonald & Woodward Publishing Company, Inc., Blacksburg, Virginia.

Linzey, D. W., and A.V. Linzey. 1973. Notes on Food of Small Mammals from Great Smoky Mountains National Park, Tennessee-North Carolina. Journal of the Elisha Mitchell Scientific Society 89 (1 and 2): 6-14.

Pfitzer, D.W. 1950. Report on Mammals Collected or Observed, June-October, 1950. (Typewritten copy in files of Great Smoky Mountains National Park).

Savage, T. 1967. The Diet of Rattlesnakes and Copperheads in the Great Smoky Mountains National Park. Copeia 1967 (1): 226-227.

Stupka, A. 1935-63. Nature Journal, Great Smoky Mountain National Park. 28 vols. (years) each with index. (Typewritten copy in files of Great Smoky Mountains National Park).

Whitaker, J.O., Jr. 1962. Endogone, Hymenogaster, and Melanogaster as small mammal foods. American Midland Naturalist 67: 152-156.

Whitaker, J.O., Jr. 1999. Woodland Jumping Mouse. Pages 665-666 . In: D.E. Wilson, and S. Ruff (eds.). The Smithsonian Book of North American Mammals. Smithsonian Institution Press, Washington, D.C.

Whitaker, J.O., Jr. and R.E. Wrigley. 1972. Napaeozapus insignis. Mammalian Species No. 14: 1-6. American Society of Mammalogists.