Woodland Jumping Mouse (Napaeozapus insignis)

County List:

Rule:

Forested or Mixed Forested/Nonforested Landscapes

      (Assorted Hardwoods (Sap or Pole or Sm Saw or Lg Saw or Uneven))
      (Northern Hardwood (Sap or Pole or Sm Saw or Lg Saw or Uneven))
      or (Spruce/Fir (Sap or Pole or Sm Saw or Lg Saw or Uneven))
      or (Mixed Northern Hardwoods (Sap or Pole or Sm Saw or Lg Saw or Uneven))
      or (Mixed Upland Hardwoods (Sap or Pole or Sm Saw or Lg Saw or Uneven))
      or (Swamp Hardwoods (Sap or Pole or Sm Saw or Lg Saw or Uneven))
      or (Mixed Lowland Hardwoods (Sap or Pole or Sm Saw or Lg Saw or Uneven))
   containing:
      Dead Down Woody Debris

Habitat List:

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Literature:

The woodland jumping mouse inhabits cool, moist forests. It favors spruce-fir and hemlock-hardwood associations but also live in pure deciduous stands. This mammal prefers an environment littered with rocks, logs, and stumps and coated with a lush growth of ferns, grasses, and other plants. Moisture is important, and the jumping mouse is never far from a woodland stream or pond.

It spends the day in a grapefruit-sized nest of leaves and grass inside a burrow, under a log, or within a brush pile.

This rodent relies heavily on seeds throughout the warm-weather months, and it also eats underground fungi and green vegetation, as well as blueberries, blackberries, mayapples, and other fruits. Added protein comes in the form of adult beetles and caterpillars.

Habitat: Areas with herbaceous groundcover and low woody plants in both deciduous and coniferous forests, frequently in brush and herbaceous vegetation bordering streams, lakes, or ponds. Uses recent clearcuts with herbaceous cover. Seldom ventures into bare open areas.

Special Habitat Requirements: Moist cool woodland, loose soils for burrowing, herbaceous cover.

Habitat Preferences: The distribution of the woodland jumping mouse is closely related to distributions of the spruce-fir and hemlock-hardwood forest types of northeastern North America. As Wrigley suggests, however, the near similar distribution of this mouse and these forest associations may be merely coincidental. Instead, herbaceous growth and other ground cover may be more important as distributional factors than specific regimes of trees, abundant moisture, and cool temperatures in summer when the mouse is active above ground. Its major habitat preference seems to be woodland edges near water sources with undergrowth of ferns, grasses, and shrubs and with rocks, logs, and brush piles as cover. Apparently, the woodland jumping mouse rarely ventures far into open meadows, grassy swales, bogs lacking woody cover and cultivated or recently fallow fields.

In Michigan, the woodland jumping mouse has been found living in virgin hardwood forest in Alger County; in both dry and wet hardwood forest in Gogebic and Ontonagon counties; in dense hardwood saplings in Marquette County; in a sedge opening in a mixed conifer swamp at the border of Alger and Schoolcraft counties; in second-growth hardwood, second-growth fir and spruce, and tamarack and black spruce bog in Charlevoix County; along a small trout stream bordered by aspen, red maple, and shrubs in Kalkaska County; and in grassy areas shaded by second-growth ash in Montmorency County.

Behavior: The woodland jumping mouse is an excellent digger and can excavate its own burrow. It also readily uses cavities established by other species. A globular nest constructed of leaves and/or dry grasses often occupies an enlargement in the shallow tunnel. Nests may also be placed in brush piles on the surface of the ground.

Food Habits: Their fare depending on season, contains about 70% seeds and other plant foods and 30% insects and other soft-bodied invertebrates.

Results: More Napaeozapus insignis were captured in hardwoods than in softwoods. The significant interaction among the four hardwood stands obscured the relative effects of red maple and northern hardwoods. Within northern hardwoods, the poletimber stand contained more individuals than the sawtimber stand, whereas the opposite was true in red maple stands. Likewise, within sawtimber stands, red maple was used more than northern hardwoods whereas in poletimber stands northern hardwoods were used more than red maple.

Discussion: Napaeozapus insignis inhabits spruce-fir and hardwood-hemlock stands in North America. Its range coincides with the combined ranges of eastern hemlock and balsam fir (except in the boreal forest-tundra ecotones), although Brower and Cade found no preference for any particular species of woody plant cover. Napaeozapus insignis has been reported both to prefer waterside habitats and to show no preference for habitat near water. This species' habitat distribution is either poorly understood or it shows great geographic variation. Shrubs and woody ground cover also have been associated with N. insignis; Lovejoy reported highest captures at sites with these characteristics and high levels of invertebrate food. He also noted a preference for fallen logs, slash, and other cover. Results of the present study show a greater abundance in deciduous cover than previously reported. Greater densities of shrubs and ground cover in deciduous stands are probably important characteristics favoring N. insignis, but do not account for greater use of young northern hardwoods and mature red maple stands.

Too few Napaeozapus insignis were captured in 1971 to permit a meaningful analysis, although none of the four individuals were captured in the coniferous zone. In 1972. N. insignis exhibited a statistically significant negative association with both the coniferous zone and the wet trap stations. The avoidance of the conifer zone with its general lack of ground cover was consistent with the findings of Brower and Cade, which indicated that this species was least abundant in coniferous habitats on Whiteface Mountain (Adirondacks). Although N. insignis was more abundant in the moist habitats, as previously noted by Preble and Whitaker and Wgigley, individuals also appeared to select the drier sites within the wetter areas on Tahawus grid.

The woodland jumping mouse was more abundant in the sapling stage than in uncut softwoods or the slash stage. Uncut and partially cut hardwoods were used more by the Woodland Jumping Mouse than all softwood types except the sapling stage.

The greater abundance of woodland jumping mice in the sapling stage compared to the slash stage or uncut softwoods may relate to their preference for dense shrub cover.

Abstract: Population densities of the woodland jumping mouse were studied on logged over and control sites in east-central New Hampshire from May 1968 to December 1969 by live-trapping and snap-trapping. Largest numbers were captured on the older (>2 years) seral stages and on certain moist uncut areas. Highest population densities occurred where there was low woody vegetation cover, high soil moisture, and abundant invertebrate food.

Northern hardwood forest - beech and sugar maple were dominant species.

Results: Highest population densities of N. insignis occurred on moist uncut areas or on those logged areas supporting dense cover in the form of low woody vegetation (3-4 year stage, 15-16 year stage). The Burn, recently logged areas, and dry uncut areas supported low populations of this species.