As boys, my brother and I were once given the task of removing a large snapping turtle from our aunt’s horse pasture. They feared the soft muzzle of one of their fine Arabians was in danger of a good nipping. We coaxed the offending turtle into a large feed bucket and set off intending to deliver it to a nearby pond. My brother had no sooner picked up the bucket than I glanced down and saw the big snapper’s head and neck slowly easing outward from under the carapace. I had the distinct image of a bowstring being slowly drawn to tautness.. “Look out,” I shouted. My brother let go of the bucket handle just as the turtle’s gaping maw shot upward toward his hand. He kept all his fingers but did end up with a surgical-like incision across the knuckles of his middle finger. We did get the turtle to the planned pond but henceforth we both gave all snapping turtles we encountered much more respect.
Snapping turtles, of which there are two species in Indiana, belong to a family known as the Chelydridae. This name is derived from a combination of the Greek terms for turtle and water. The geographic range of the huge alligator snapping turtle extends only into extreme southwestern Indiana. This species, which prefers riverine habitats, is the largest freshwater turtle in North America. As a graduate student, I recall seeing one which was in captivity at the Brookfield Zoo in Chicago. At that time, the turtle weighed nearly 220 pounds as I recall. Upon its death in 1982 it had maxed out at 236 pounds. The largest wild specimen known is said to have weighed in at 219 pounds. The alligator snapping turtle is more common in the southern United States but is threatened by overharvesting in some areas. In Indiana and Illinois it is a protected species. The alligator snapping turtle spends much of its time lying under water, in ambush mode, on the muddy substrate. It is unique among turtles in having a fleshy projection of the tongue which is used as a lure to attract prey into range of its jaws. The chelydrids at GPFWA are the eastern or common snapping turtles (Chelydra serpentina). The specific moniker is in reference to the snake-like head and neck of this species. Common snapping turtles, while not nearly the size of their big cousins, are still among the largest of fresh water turtles. The typical range of weights for this species is 20-25 pounds. The late Sherman Minton, Indiana’s preeminent herpetologist, reported seeing a specimen from Noble County (NW of Fort Wayne) that weighed 46 pounds, the largest he had seen. One of the reasons that this turtle is so common is that it is a supreme generalist in regards to the habitats it utilizes.
While adults prefer larger, deeper bodies of water common snapping turtles will make use of ponds, ditches, marshes, and the quiet waters of streams. They often wander far from water especially in springtime. Common snapping turtles are also quite catholic in regards to their diet, another reason for their success. Typical food items include aquatic plants, crayfish, frogs, tadpoles, insects, fish, and carrion. Common snapping turtles may hibernate during the winter time. Minton mentions them using muskrat lodges or sheltered areas on the bottom of ponds or lakes. However, these turtles may be active in the winter and have been observed moving about in the water beneath a frozen surface. Common snapping turtles, like other members of the turtle clan, are oviparous which means that they lay eggs. Female snapping turtles dig a nest cavity using their hind feet and deposit eggs into this cavity after which it is covered over. Typically around two dozen eggs are then left (2.5 – 3 months) to hatch on their own. Like some other reptiles the incubation temperature of the eggs determines the sex of the hatchling which will emerge. Eggs exposed to temperatures of 22-28C produce males. Nest temperatures below 20C and above 30C produce females. A study by Wilhoft, Hotaling, and Franks (1983) found that eggs near the surface of the nest usually produced female hatchlings while those on the bottom produced males. The nests of common snapping turtles are vulnerable to predation by raccoons, skunks, and foxes. In Indiana, the common snapping turtle is considered a game species. They may be taken year round. One must have a hunting or fishing license to take any reptile from the wild but as a game species snapping turtles (as well as the two soft-shelled turtles) are subject to bag and possession limits. Go to: http://www.in.gov/dnr/fishwild/3328.htm for more information. By the way, while on the subject of turtles, don’t forget that the eastern box turtle is now a protected species in Indiana. They are not to be taken from the wild. Common snapping turtles are, naturally, of interest to turtle hunters because of their edibility. A quick perusal of the Internet will yield a plethora of recipes for turtle soups and stews. MacGowan, Kingsbury, and Williams in their Turtles of Indiana suggest that the species may be under threat in certain areas because of its use for human consumption. But of course sometimes the turtle wins.
Last summer my wife and I sat waiting for a freight train to clear the tracks in southern Sullivan County. At idle In front of us sat a well-used pickup truck, the bed holding an assortment of treasures. As I sat absentmindedly observing the passing train a movement from the truck’s bed caught my eye. At first I thought the passengers had thrown something out the window. But, as I looked more closely, what I saw was a fairly large common snapping turtle lying on its back in the road. Having climbed up the inside of the truck bed and pitched itself onto the road, it was now struggling to overturn itself. With deft exertion of its head and long neck, the turtle quickly flipped itself upright and began to hightail it toward the nearest roadside ditch. I could imagine the disappointment that would result when the truck’s driver found his much anticipated turtle stew no longer existed. For a fleeting moment I contemplated alerting him to the fact that his dinner was rapidly heading for cover. But I didn’t. In soft-hearted acknowledgment of the old reptile’s powerful survival instinct, I gave a silent cheer as it disappeared into the water-filled ditch. I appreciated the fact that one doesn’t survive since the Paleocene without having an attitude and a good dose of toughness.
Useful Resources Oktay, Sandra D. 2009. Snapping Turtles. http://yesterdaysisland.com/archives/science/5.php. Yesterday’s Island. Today’s Nantucket. 39 (5).
MacGowan, Brian J., Bruce A. Kingsbury, and Rod N. Williams. 2005. Turtles of Indiana. Purdue Extension Publ. FNR-243. West Lafayette, Indiana.
Minton Jr., Sherman A. 2001. Amphibians and Reptiles of Indiana. Indiana Academy of Sciences. Indianapolis.
Wilhoft, D.C., E. Hotaling and P. Franks. 1983. Effects of temperature on sex determination in embryos of the snapping turtle, Chelydra serpentina. J. Herp. 17: 38-42.
The reproductive behavior of river otters is interesting in that they, like many other mustelids, exhibit delayed implantation. Mating occurs most often in the spring (March-April) but the fertilized egg does not implant in the uterine wall immediately. Implantation is delayed for several months. As a result, although the actual gestation period averages about six weeks, the young are born the following spring. Average litter size is 2 to 4. Delayed implantation seems to be associated with life in temperate climates and longer life spans. However, the adaptive value of such a diapause seems to be poorly understood. (http://www.ncbi.nlm.nih.gov/pubmed/15058730). Otters den most often along the bank of their aquatic habitat. They may use natural tunnels for their dens but have also been known to eject the original builder, a beaver or muskrat for example.
Otters in general are often described as curious and playful. Personal observations have convinced me that they are. My wife and I escaped to Florida this winter and in the canal behind our house lived river otters. Occasionally they would come by our boat dock for a visit. Coming to the shore, or actually climbing up on the dock, they would linger and peer up at us as inquisitively as we watched them. We would often see them nudging a leaf or potential food item through the water with their nose. Releasing it, they would dive in their wonderfully graceful manner only to return for more play. Many years ago, we visited Peace Corps colleagues in Thailand who had two small-clawed otters living in their house. These are small, Asian relatives of our river otter. The two bundles of energy seemed to spend most of their day at play racing through the house in a game of “catch me if you can”. One of their favorite toys was a wooden box containing a ball. There was a hole in the box through which the otters could reach and thus grasp the ball. However, the hole was too small to allow them to pull the ball out with their paw wrapped around it. As we sat and chatted with our hosts, the otters would race into the living room tumbling over one another. Suddenly, as if seized by a momentary obsession, one of them would run to the box and insert a front paw. With a look of intense concentration, it would manipulate the ball for a few seconds. After what seemed to be a most pleasing bout of tactile stimulation, it would withdraw its paw and shoot off into another room with its partner in full chase. It did indeed look like loads of fun.
River otters do occasionally conflict with the interests of humans. This most often occurs when otters choose a private pond or fish hatchery as their larder. With the increase in river otter numbers in the state has come a rise in the number of damage grievances filed. In 2011 the DNR received 34 such complaints. In 2012 the number rose to 69 and, in 2013, 86 complaints were noted. Fencing has been suggested as one method for preventing such depredations. It should be noted that river otters prey heavily upon slower moving, nongame fish species (Whitaker, 2010). These include suckers, chubs, dace, and darters. However, they do not eschew bluegills and other sunfish. As adults, river otters have few enemies other than humans. However, their young may be vulnerable to predators such as coyotes and bobcats. Perhaps the recent arrival of the river otter at GPFWA is a harbinger of things to come. Although some might begrudge this fish-eating species as a competitor, it does represent the return of an Indiana native. The presence of the river otter is but one more example of the oft-cited adage – “build it and they will come”. We have certainly seen this to be true in regards to the avian visitors and residents of Goose Pond. Perhaps we will now see the palette of mammalian species inhabiting the GPFWA ecosystem become more brilliant as well.
Whitaker, Jr., John O. 2010. Mammals of Indiana. A Field Guide. Indiana University Press. Bloomington.
*otter photo courtesy of Indiana Public Media
Eastern cottontails will utilize habitats of many different types. However their preference seems to be for oldfield type environments, particularly those which contain briars and brush. Although they may occur in wooded habitat and even in urban areas, thick ground cover is optimal for them. Cottontails do not burrow but will readily utilize subterranean dens made by other mammals such as woodchucks. Eastern cottontails eat a wide variety of plant materials. Warm weather foods might include grasses, clover, and plantain. During the winter, eastern cottontails turn from grazing and become browsers. During this time they eat the bark and sprouts of woody plants such as maple, sassafras, and briars. The feeding habits of cottontails are interesting in that they are able to consume large amounts of vegetation quickly and then convert it into a form for later use. This allows them to reduce the amount of time that they forage in the open where they are vulnerable to predators. Later, withdrawing to a more secluded spot they will produce fecal pellets that are nothing more than undigested plant material. These pellets look very much like little miniature versions of the alfalfa pellets one might feed to livestock. The cottontails then eat these fecal pellets and this time more completely digest the organic material in them. A feeding behavior such as this is known as coprophagy.
The reproductive potential of the eastern cottontail is indeed great. Given its many enemies, it is a good thing it can quickly regenerate its numbers. Average litter size is around five young and they can produce as many as half a dozen litters per year although three or four is more common. The gestation period is about one month. The young are born in a slight depression in the ground made by the female which she lines with grass and with fur plucked from her belly. Young rabbits begin to leave the nest and forage on their own by the second week following their birth. Eastern cottontails really do have a tough go of it. Although it is possible for some rabbits to live over three years, the average life expectancy is slightly less than one year. Decimating factors include parasites, disease, and predators. Of course, nowadays automobiles are an extreme hazard to cottontails. This is especially true where habitat availability is minimal and may consist primarily of roadside vegetation. Mumford and Whitaker (1982) list some twenty species of parasites found on eastern cottontails. These included a variety of fleas, mites, and ticks. An important disease of rabbits is tularemia given that this bacterial infection may be transmitted to humans. My grandfather was always insistent that I thoroughly wash my hands with soap, and then give them a good dousing with rubbing alcohol, after cleaning the rabbits we harvested. Look out for “rabbit fever” he warned. Mumford and Whitaker studied 68 case histories of tularemia and found that 88% of them involved contact with rabbits. The disease may also be transmitted by ticks. If this disease is unfamiliar to you, there is an interesting discussion on Wikipedia.
The predators of eastern cottontails are many. These include the red fox, gray fox, and coyote. Domestic cats will also take them. Serpents such as black rat snakes may eat young cottontails. Avian predators know to attack cottontails include barn owls, long-eared owls, great horned owls, rough-legged hawks, northern harriers, red-tailed hawks, and crows. Of course humans take a great number of eastern cottontails during the hunting season. At Goose Pond FWA however eastern cottontails seem to be an under utilized late-season game resource. GPFWA Property Manager Travis Stoelting reported that only 38 rabbits were taken by hunters last year. This may be a reflection of the fact that the state has seen a general decrease over the years in the number of hunters pursuing rabbits. A 2011 article by Paul Moore, in Game & Fish Magazine, reported that around 200,000 rabbits are taken annually in Indiana compared to former numbers which were closer to one million. Looking further back, the latter number pales in comparison with the 2,243,000 cited by Mumford (1969) as the average number taken annually during the 1950’s. The number of rabbit hunters has also declined over the last few years from around 200,000 to 70,000. Moore believes that a shift toward more hunters pursuing deer and wild turkey have contributed to this decline. Additionally, he believed loss of habitat had resulted in decreased rabbit numbers. This is also a deterrent to hunters who might otherwise pursue rabbits. For those of us who have hunted the eastern cottontail with avid interest, it is no wonder that this species was at one time the most popular game animal in Indiana.
These days I find myself much more prone to photographing or simply watching a game animal. Such, I suppose, is the waning of the desire to take that comes with age. But I still recall with great fondness the hours I spent afield, as a young man, in pursuit of rabbits. The camaraderie of hunting companions, the genuine enjoyment of watching a good pair of beagles happily at work, and the thrill of the chase all bring pleasant memories. Of course the remembrance of a plateful of fried rabbit backed up by a healthy portion of biscuits and gravy is not to be lightly dismissed either. There is no wild game of finer taste in my humble opinion. In considering the many interesting aspects of the natural history of the eastern cottontail, as well as its historical importance as a small game mammal, we are forced to accept the presence of this little mammal at Goose Pond FWA as yet one more reason to celebrate the property’s wonderful biodiversity.
Mumford, Russell E. 1969. Distribution of the Mammals of Indiana. Ind. Acad. of Sci. Monograph No. 1 Mumford, Russell E. and John O. Whitaker, Jr. 1982, Mammals of Indiana. Indiana University Press. Bloomington, Indiana.
This brief story does illustrate the fact that a good many people, even as adults, possess a rather unreasonable fear of the common water snake. As a retired biologist, I can’t recall the number of times people would report seeing one of these snakes while fishing or otherwise being around the water. Invariably they would refer to this animal not as a common water snake but as a “water moccasin”. Despite my assurances that what they had seen was not an example of that highly venomous species, I had the feeling that my explanations were often falling on deaf ears. There are two points to be made here. First, this confusion is a really good example of why biologists generally prefer scientific names over common names. As most of you probably know, each species of organism has its own scientific name. Such names are generally derived from Latin or Greek. They are comprised of the Genus name (in this case Nerodia, referring to the snake’s habits) and the specific name (here it is sipedon, which refers to its bite). A common name on the other hand may refer to different organisms. These two snakes are an example. Sometimes a common name is used for totally different animals. The term gopher may bring to mind a turtle in Florida, a true pocket gopher in Illinois, or a ground squirrel in Indiana. Sometimes common names can mislead; a starfish or a jellyfish is not really a fish. So, to make a long story short, folks living within the range of Nerodia sipedon often simply use the common moniker of “water moccasin” for this species. A second reason that the common water snake is often mistaken for a true water moccasin, or cottonmouth, is that they do indeed look quite a lot alike. Incidentally, the western cottonmouth (Agkistrodon piscivorus) does actually occur in Indiana. In 1983 a relic population of this snake was found in Dubois County. The cottonmouth is listed as an Endangered Species in Indiana. There are, of course, significant differences in the anatomy of common water snakes and the cottonmouth. The differences are such that they are placed into different families (Colubridae and Viperidae). Think of it as being like separating carnivores into the cat family and the dog family. Nevertheless, many of the water snake species bear a strong resemblance to the cottonmouth in terms of coloration, stocky build, and habitat preference. Another story might illustrate how much alike they really can look at times. My wife and I had the opportunity a few years ago to canoe the Wekiva River in central Florida. She sat in the bow; I was at the stern. It was a beautiful stream which quietly flowed through forests of cypress and gum and we leisurely paddled our way along attentive to any animals we might spot. As we rounded a bend, I saw a fallen tree whose barren branches hung out over the stream. In the top of this tree, some ten feet above the water, basked a good sized snake. The large heavy build, broad head, and distinct dark cross-bands on a brownish body fairly shouted cottonmouth to me. Urging Anne to help me paddle closer, I continued looking upward at the somnolent snake. Now, the closer I got, the less sure I became of my identification. I asked Anne to help me move a little nearer. Now, in close proximity to the snake, I became convinced that it was after all simply a Nerodia species of some sort. If only I could get a little nearer I could be certain. Suddenly I became aware that in spite of my strong paddling I was making no headway in getting closer to my quarry. It was then that I looked to the bow of the canoe to see Anne furiously beating the water to froth. I had inadvertently put her into a position whereby the snake in question loomed ominously right over her head. The turbulent flow issuing from her paddle would have done the old stern-wheeler Mississippi Queen proud. Needless to say I got no nearer the serpent but by now it had indeed resolved itself into a brown water snake. No big deal.
As one would expect of such a highly aquatic snake, their diet consists of fish of assorted kinds including various minnows and catfish. Common water snakes have little impact on game fish populations. They will also eat frogs and toads, their tadpoles, and salamanders. Water snakes are ovoviviparous which essentially means that females retain their eggs internally until the yolk-fed young are born alive. The number of offspring in a litter may be several dozen but the average seems to be around eight. Water snakes of all kinds do of course have their own predators. Large fish, such as bass, as well as wetland birds such as herons will take them. Marshland mammals including raccoons and mink will also prey on snakes. Juvenile water snakes may even fall victim to bullfrogs. It is best to enjoy a chance meeting with the common water snake from a distance. Although non-venomous and essentially harmless, they do have a nasty disposition. Given a chance they will flee but cornering or trying to handle them seems to bring out their dark side. In such cases, they will bite fiercely and often. Common water snakes, by acting alternatively as predator and prey, serve as an important cog in the complex ecological machinery of the wetland. Oh, and one more thing. Let’s not call them water moccasins.
For those with further interest in Indiana snakes, I recommend:
Conant, Roger and Joseph T. Collins. 1998. Reptiles and Amphibians: Eastern/Central North America. Peterson Field Guides. Houghton Mifflin Co. New York.
MacGowan, Brian and Bruce Kingsbury. Snakes of Indiana. IUPUI Fort Wayne and IDNR, Division of Fish and Game. Indianapolis.
Minton, Sherman A. 2001. Amphibians & Reptiles of Indiana. Indiana Academy of Sciences. Indianapolis.
The volume and tone of their call immediately suggests size and the Bullfrog is indeed our largest Indiana frog. In fact the Bullfrog is the largest frog in North America and one of the largest in the world. The average body length of the Bullfrog is about five inches (record eight inches according to Minton2001). Their enormous legs can add another eight to ten inches to the total length. Average weight is around a pound. I once saw a Bullfrog leap from the water in an attempt to snag a meal of Red-winged Blackbird. I also seem to remember running across a newspaper article years ago which had a photo of a Bullfrog which had a rattlesnake in its mouth. Such dietary endeavors obviously suggest an anuran of extraordinary size and strength. Bullfrogs will apparently eat about anything they can stuff into their mouths. Minton lists among their prey animals such as crayfish, insects, insect larvae, other frogs, minnows, tadpoles, and small mammals. They really are quite voracious. This gastronomic quality has a downside. Bullfrogs are native primarily to the Midwestern and eastern United States. However they have been introduced into many western states and even some foreign countries (such as Canada and Taiwan). These introduced frogs, as is typical of invasive species, invariably cause ecological damage among native faunas. Incidentally, we have another frog which is somewhat easy to confuse with the Bullfrog. The Green Frog is also large and has a coloration and general body form quite similar to those of the Bullfrog. A distinguishing feature is that the Green Frog has a ridge of skin (called the dorsolateral fold) which runs along the outer edges of its back. The bullfrog’s skin in this area is smooth, not raised into a fold. The call of the Green Frog has often been likened to the twanging sound of a plucked banjo string. It has neither the bass nor volume of the Bullfrog’s call.
Like most other frogs, Bullfrogs reproduce in the water. They practice external (though direct) fertilization of the eggs therefore the water is necessary as a medium for the sperm to swim into contact with the eggs. Eggs are laid in tremendous numbers and hatch within a few days. May through July seems to be the primary period for egg laying. Bullfrog tadpoles typically take one to two years to metamorphose depending on latitude and thus water temperature. Like other anurans (frogs and toads), Bullfrogs hibernate during the winter by burying themselves in the bottom mud, or under submergent debris, in their aquatic habitats – marshes, ponds, streams, strip-pits. Bullfrogs are prized by many for the edible quality of their legs. To hunt Bullfrogs in Indiana, once must have a hunting license and the season is regulated. Hunting Bullfrogs (and Green Frogs) is permitted from June until April of the following year. This season the specific dates are June 15, 2014 – April 30, 2015. There are certain restrictions on how these species may be taken. Hunters may use a gig or spear with a head not more than three inches in width and a single row of tines. It is also permissible to use a long bow and arrow. A person may use their hands, a club, or a fishing pole (or hand line). Not more than one hook or artificial lure may be attached to the line. The only type of gun allowed for frog hunting is a .22-caliber firearm and it must be loaded with bird shot.
Minton, Sherman A. Jr. 2001. Amphibians and Reptiles of Indiana. Indiana Academy of Sciences. Indianapolis.
The striped skunk was, for many years, placed by taxonomists into the same family as the weasels. With the rise of molecular biology (DNA analysis particularly) this taxonomy has been revised. Skunks are now placed into their own family which is called the Mephitidae. In the eastern United States there are two species within this family, the striped skunk and the spotted skunk. The latter is now considered extinct in Indiana. It is thought that Indiana was positioned at the northern edge of the spotted skunk’s geographic range. Written references to spotted skunks in Indiana are based upon specimens from more southerly counties such as Knox and Posey. So far as I am aware, the only actual physical evidence of spotted skunk in Indiana is a mandible found in a cave in Lawrence County in the late 1950’s. Our striped skunk bears the scientific moniker of Mephitis mephitis. This name is derived from the Latin word for a noxious vapor. The ability of this species to spray such a “vapor” is likely the aspect of the striped skunk’s biology most familiar to people. I’m sure many of us have had the unpleasant task of trying to rid our dog of the odor bestowed upon it as the result of an impetuous assault on a striped skunk. The spray of the skunk is comprised of a chemical with an official name as long as one’s arm but it is basically a sulfur-containing compound called butyl mercaptan. This chemical is forcefully released from a pair of glands located just inside the skunk’s anal opening. The spray is a defensive weapon of course and its effect goes well beyond being unpleasant to smell. I was once afield with one of my dogs when it ran afoul of a striped skunk. Perceiving the dog, the skunk arched its back, raised its bristles and tail, and quickly turned its posterior to the dog. All of these were signs that it meant business. The dog in question was about to have its first encounter with an exceedingly irritated striped skunk. Growling and rushing toward the skunk, the dog received a full blast of the spray in its face. The reaction was immediate and intense. Yelping and leaping away from the skunk, the poor victim began salivating powerfully. The pitiful hound shook its head violently as if attempting to throw off the substance so painfully attacking its eyes. He rubbed his face upon the ground as the powerful burning in the eyes intensified. The nauseated dog retched, foamed at the mouth, and otherwise demonstrated the total debilitation the skunk had inflicted upon it. Henceforth I had a much greater appreciation of just how effective the defensive spray of a striped skunk could be. Under normal circumstances, and given room to maneuver, the striped skunk is perfectly content to mind its own business.
Most of the individuals I’ve run across were busily moving along with their peculiar waddling gait, nose pressed to the ground in their apparently perpetual search for food. Striped skunks are omnivorous although they do have a tendency to feed heavily upon insects. These often take the form of beetles and their larvae, the so-called grubworms. Skunks will also eat other mammals including mice and shrews. Bird eggs and fruits, such as persimmons, are common in the diet of striped skunks too. Striped skunks utilize a variety of habitats including woods, oldfields, vegetated fencerows, riparian vegetation, and brushy fields. They are sometimes seen abroad during daylight hours, especially toward evening, but are mostly nocturnal in their activities. Striped skunks utilize burrows as dens. These may be dug by the skunk itself or may have been constructed by woodchucks or other larger burrow-diggers. Striped skunks have one litter of young per year (February or March) and generally produce four to six offspring at a time. Striped skunks, like most wild mammals, harbor a variety of parasites including fleas, lice, mites, and ticks. Internal parasites which have been found in skunks include flukes, tapeworms, and nematode worms. They are also vulnerable to distemper and rabies. As noted, being killed upon a road is a major danger to striped skunks. One their major natural predators is said to be the great horned owl. The striped skunk represents just one more mammals that you might encounter on a visit to the Goose Pond FWA. Although often castigated by humans, the striped skunk is but another example of an exceedingly interesting mammalian species busily attending to its role in the grand web of wetland life.
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
Folks often ask why beavers so diligently work to build and maintain their dams. They do so for several reasons. By constructing dams across running waterways, beavers create a pond of some depth. These large rodents (second only to the South American capybara in size) utilize underwater entrances to their burrows and lodges. By creating a pond, beavers are thus able to enter their dens hidden from potential predators. Having deep water in which to plunge also allows surface swimming beavers to avoid danger by diving. Such an escape dive is often preceded by a wallop to the water’s surface with their broad, flat tail. The sound is much like the shot of a .22 caliber rifle and alerts other beavers to the presence of danger. Impounded water also provides the beavers with a means of floating pieces of vegetation to a lodge or dam. In the winter, the deep beaver pond may freeze near the surface but the unfrozen depths still allow the animals to move in and out of their lodges to forage for food.
In regards to food, beavers are vegetarians. Their diet consists primarily of the bark and/or twigs of trees such as cottonwood and willow. These trees are favored because they conveniently grow close to water (such plants are hydrophytic in ecological terms) and have soft wood which makes for easier gnawing. Like other rodents, beavers have one pair of enlarged incisors in the upper and lower jaws. The incisors of beavers are massive and allow them to fell a six inch cottonwood in a matter of minutes. Felled trees are then cut into sections and transported. Some may be used for lodge construction; others may go into building or repairing a dam. Many branches, and small logs, are stored on the bottom of the beaver’s pond near the lodge. The green wood is heavy, becomes waterlogged, and thus lies on the bottom. Here it is available for the beaver, during the winter especially, to simply swim out of the lodge and select a branch from its larder. This wood is usually taken back onto the dry, raised platform within the lodge where the bark is eaten. The bare branch is then taken back outside and discarded. Such bark-stripped branches littering the shore are another common sign of beaver activity in a given area. In the spring and summer other aquatic plants may be eaten. These include cattails, water lilies, sedges, and grasses. Beaver will also feed on standing corn. Just last month, in Sullivan County, I happened upon a well-defined beaver trail leading from a stream directly into a ripening corn field. Although I have made several references to the beaver’s lodge, they do not always construct such structures. In our area, with the numerous lakes formed by strip-mining for coal, the water depth is sufficiently great as to negate the need for lodge construction. In such habitats, beavers typically burrow into the banks of the lake. However, even such bankside dens are often marked by a heavy accumulation of logs, limbs, and twigs which have had their bark eaten away. As a result the location of the den entrance, even though it is below the waterline, is quite obviously marked.
Beavers, like many other animals, tend to bear their young (called “kits”) in late spring or early summer. Litter size averages three or four offspring. Young beavers stay with their parents for a couple of years and then are driven away by the adults. Thus, a typical beaver colony consists of around six animals; these being the two adult parents and the young of the past year or two.
The behavioral repertoire of beavers is quite fascinating to those of us who enjoy natural history. However, their increasing abundance in Indiana and elsewhere has caused incidences of human-beaver conflict to escalate too. Usually the disturbances caused by beaver activity take one of two forms: cutting of trees or flooding. As mentioned, beavers usually feed on cottonwoods and willows. However, they may enter the yards of people living near lakes and fell a favorite maple or oak tree just as readily. Because of their dam-building instinct, beavers may flood croplands, lawns, or even roads. These activities may present a serious risk to both the economic and personal wellbeing of humans. Burrowing into pond dams and levees, thereby weakening them, is another common problem caused by the activities of resident beavers. According to Department of Natural Resources statutes, landowners (or tenants) can destroy or capture nuisance beavers without a permit if the animal is discovered damaging one’s property. If this is done, your action must be reported to a conservation officer with 72 hours. Captured animals may be released elsewhere but there are restrictions. First, the animal must be released in the county of capture. Also, one must have permission from the landowner before a captured nuisance animal is released onto their property. This constraint refers not only to private property but includes land belonging to city, county, or state entities. In spite of their potential to cause annoyances, beavers are exceedingly interesting creatures. Let us all be thankful for properties such as Goose Pond FWA. Here we are able to observe and ponder, without vexation, the fascinating behaviors of one of the most characteristic of wetland mammals.