In previous editions of Critter Corner I have dealt with Goose Pond FWA’s larger and more economically important mammals. Most of these (muskrat, mink, and beaver) are typical wetland mammals. However, we should recall that GPFWA contains habitats other than wetlands. Much of the property supports restored prairie and old-field habitats. The latter we may define as abandoned pasture or cropland which has grown into an assemblage of grasses, forbs (broad-leaved flowering plants), and/or shrubby vegetation. Common grasses could include brome grass, foxtail, bluestem, fescue, and panic grass. Characteristic forbs in old-fields are goldenrod, ironweed, Queen Anne’s lace, and daisy fleabane. Representative old-field shrubs or woody plants might include blackberry, raspberry, sumac, red cedar, and maples.
Within these grasslands and old-fields live arguably the GPFWA’s most abundant mammals – the “field mice”.
I say “field mice” parenthetically because this is the term generally applied to any mouse-sized rodent a lay person sees scamper from underfoot. In reality, there are at least ten distinct species of small mammals in Indiana that would fit that description. Of these, one of my personal favorites is the meadow jumping mouse. My specimen catalog tells me that I first encountered this species in July of 1969. Previous to that, I was unaware that such an interesting little animal even existed. Looking at that first specimen of Zapus hudsonius, I was struck by its handsome coloration. The sides were yellowish with scattered dark hairs. The mid-dorsum was a darker yellowish-brown, the belly white. The total length of the specimen was around eight inches, but over half this length was comprised of its surprisingly long tail. Typically a mouse this size has a hind foot length of about 0.7 inches. The hind feet of the jumping mouse measured well over an inch and were much larger than the front feet. Given this description, perhaps you can form a visual picture and understand my initial fascination with this mouse. Looking at it was akin to peering at a miniature kangaroo. Walking through a field of grasses or forbs, it would not be surprising for you to catch a glimpse of this little mouse as it bounds away in a series of kangaroo-like leaps of two feet or so. After hopping away in this manner, the meadow jumping mouse typically darts into thicker cover or sits quietly relying on its camouflage for further protection.
Technically speaking, the meadow jumping mouse is not seen on the list of mammals found at GPFWA during the 2010 biodiversity survey of the property. During the survey’s collecting period none were taken. However I have seen an individual leaping away, in the manner described above, in the southern part of the property. This individual was in the typical heavy herbaceous cover preferred by meadow jumping mice.
Whitaker (1982, 1998, 2010) and Mumford (1969) both report that the meadow jumping mouse is often partial to dense stands of touch-me-not (Impatiens) and that it utilizes the seeds of this plant as an important food source as well. Other major foods in the diet of meadow jumping mice include the subterranean spores of the fungus Endogone, foxtail and other grass seeds, and lepidopterous (moth/butterfly) larvae.
Lest, after reading this, you head for the GPFWA to try to flush a meadow jumping mouse, be aware of one other most interesting trait of this species. It is a deep hibernator. Records show that the third week in November is the latest that this animal appears to be active. It then retreats to an underground nest constructed of plant materials. Here, at near freezing temperatures, it reduces its heart rate, respiration rate, and body temperature as it sleeps away the remainder of the winter. Assuming that they have enough fat reserves to survive hibernation, meadow jumping mice then reappear above ground in late April or early May.
While humans often completely overlook animals such as the meadow jumping mouse as a component of an ecosystem, such species are important in the natural scheme of things.
Jumping mice are preyed upon, and thus help sustain, other species such as barn owls and red-tailed hawks. Serpents such as prairie kingsnakes and black rat snakes may feed upon them. Other mammals too, including foxes and coyotes, will eat jumping mice. The mice themselves help maintain an ecosystem’s ecological balance by preying upon insects and feeding upon plant seeds. All in all seldom recognized and little appreciated small mammals, like the meadow jumping mouse, represent still one more engaging component of the GPFWA fauna.
Jackson, Hartley H.T. 1961. Mammals of Wisconsin. The Univ. of Wisconsin Press. Madison.
Mumford, Russell E. 1969. Distribution of the Mammals of Indiana. Ind. Acad. Sci. Monograph No. 1
Whitaker, J.O. Jr. and Russell E. Mumford. Mammals of Indiana. Indiana Univ. Press. Bloomington
__________and William J. Hamilton. 1998. Mammals of the Eastern United States. Cornell Univ. Press. Ithaca, NY.
Whitaker, J.O. Jr. 2010. Mammals of Indiana- a Field Guide. Indiana Univ. Press. Bloomington