The jumping mouse, genus Zapus, is distributed pretty much throughout North America north of Mexico. There are three species, Zapus hudsonius (meadow jumping mouse), Zapus princeps (western jumping mouse) and Zapus trinotatus (Pacific jumping mouse). The meadow jumping mouse is found in eastern US and Canada, extending northerly into Alaska. The western jumping mouse is found in western states and into Canada. The Pacific species inhabits the Pacific coast in California and extends northward along the shoreline and more into the interiors of Oregon, Washington, and British Columbia.*
The jumping mouse is slightly larger than the common house mouse. It has a long tail and hind legs much longer than fore legs. Fur is different shades of brown with white or whitish underparts. The western jumping mouse has bicolored pelage, with pale to grayish brown above, white to yellowish-white below.** It is well adapted to live in a variety of habitats, from grassy fields, vegetation along bodies of water, and in dense vegetation in wooded areas. The jumping mouse moves with a series of zig-zag hops and horizontal leaps. When fighting, the mouse squeaks. It rattles its tail, kicks with hind limbs, pushes with their forelimbs, and rattles its tail. Runways are obvious, cluttered with grass clippings. Jumping mice are mostly nocturnal in activity and are goos swimmers.
One of the remarkable characteristics of the jumping mouse is its ability to hibernate; it is one of the longest mammalian hibernators. From one-half to two-thirds or more of its life is spent in hibernation. Length of hibernation varies generally from September to April. Pre-hibernation deposition of fat depends on abundance of seeds and green vegetation. There is significant weight loss during hibernation and mortality occurs among individuals with insufficient fat deposits, especially among juveniles. If spring soil temperature do not change to above 8.0 to 9.5 degrees C, and if body weight drops below 18 to 19.5 g, animal mortality is high. Arousal from hibernation usually occurs when soil temperatures rise above 9 degree C in the spring.
Hibernation nests vary among species and individuals. Some are often found 0.5 m. or so below ground surface and often constructed of grass.
*Hall, E. R. 1981. Mammals of North America. Vol 2. John Wiley & Sons, New York.
**Hart, E. B., M. C. Belk, E. Jordan and M. W. Gonzalez. 2004. Zapus princeps. Mammalian Species, No. 749.
About Zapus, the Jumping Mouse
The three species of the Zapus jumping mouse (hudsonius, princeps, trinotatus) have much in common. Fossil forms are found in Oklahoma, Kansas, Tennessee and other areas. They normally hibernate from fall to the spring. During hibernation, breathing slows, body weight diminishes, and body temperature and oxygen consumption is lowered. Three to seven young are usually born in June after a gestation period of around 20 days. There may be more than one litter born per season. Zapus are found in a wide variety of habitat along streams and ponds and in forest vegetation. They are omnivorous feeding mainly upon the fruits and seeds of vegetation and insect larvae and fungi. Predators include owls, hawks, bobcats, weasels, skunks, raccoons, and garter snakes. They are hosts to parasites including trematodes, nematodes, bacteria, protozoans, ticks, chigger mites, fleas, botflies, etc. Home ranges are less than one acre.
As humans, we have an insatiable tendency to number, name and organize anything and everything. Often, this is healthy and it has led to our current system of animal nomenclature. Each of the following groups, from the largest to the smallest, contain progressively fewer members, though closer similarities: the largest group is Kingdom proceeding to Class to Order to Family to Genus, finally down to the smallest category, the Species. Animals of the same species are most alike, the same “kind” so to speak.
The classical definition of a species is two animals (male and female) that cannot produce fertile offspring when mated with one another. These are said to be reproductively isolated from each other. A simplistic example is a horse mated with a donkey. Even though offspring are produced (mules), they (mules) are sterile and cannot reproduce. The horse and the donkey, then, satisfy the definition of each being a separate mammal species.
The single best method for determining whether animals from different peopualtions are each valid and separate species is to actually allow mating to occur. That is to allow opposite gender representative individuals from questioned populations (male from one, female from another) to reproduce. Careful observation of offspring (if any) fertility will indicate whether or not they are reproductively viable. There are obviously a number of challenges in accomplishing this. Difficulties with this approach include:
To have a secure enclosure location where there is no chance for escape yet still large enough for several concurrent experimental matings is difficult. An enclosure for fossorial animals is necessary where boundary retaining walls are buried deep enough in the ground to deter escape by burrowing. When animals from other places are transported and placed in new and strange enclosure environments, escaping animals often disrupt normal resident animal’s well being. There are numerous unfortunate examples of exotic (non-local, foreign) animals being transported either purposefully or otherwise into new habitats. Often these lack natural controls (predators, disease, etc.) which kept population numbers balanced in the original foreign habitats. In new and similar habitats, exotic animal numbers may subsequently explode (as starlings, English sparrows, Norway rats in the U.S., rabbits in Australia, etc.) which causes unimaginable trauma and biological upheaval in formerly balanced ecosystems.
Also, it is often difficult for a researcher with little financial research support to live trap and subsequently to transport specimens from distant location to a central enclosed study facility and then manage them successfully.
Time. There must be ample time for mating, gestation, birth, growth to adults of the offspring and opportunity and time for them to mate and reproduce. Time for all of this to occur may require up to several years. Complications such as different matings, escapes, and unexpected mortality conceivably could add substantial time to the overall process.
It is often a challenge to meet governmental legal requirements and red tape. Concerns regarding transport of live specimens possibly carrying disease organisms and/or parasites from one area or country or state into another must come into consideration. Awareness of animal care guidelines is necessary.
Since actual mating experiments are rarely possible, alternatively, biologists usually go about it a different way. They seek to resolve systematic relationships by trapping a number of samples from each subject species or population being studied, one group at a time. Normally, sampling of at least 30 animals (from each population/species) is necessary for good statistical comparisons–all of which requires extensive work and resources. Measurement and analyses of representative tissues in the laboratory is labor intensive. Sophisticated statistical analyses usually follows.
Biologists work with a process called systematics, an approach using various comparison approaches/techniques in researching animal relationships. Some of the so-called important “sub-disciplines” of systematics include morphology (anatomy), physiology, phylogeny and karyology. Morphology refers to measurement and appearance differences in physical form; physiology refers to body functions; phylogeny includes consideration of relationships of near and far relatives (it is helpful to be able to identify a common ancestor); and karyology which has to do with counting and comparing chromosomes, then constructing karyograms (charts showing all individual photomicroscopically enlarged chromosomes).
This overall approach involves looking at and researching and measuring and comparing many kinds of characters from each animal group, including some of the following: fur color, behavioral aspects, size measurements, dental structure, skull measurements, activity patterns, mating habits, food preferences, hibernation (if present), tissues and DNA proteins, etc. Aboveground-dwelling animals with rapid mobility and extensive home ranges add additional challenges to animal systematists. This is because there is much greater selection of mates to pass genetic material over a larger geographical area.
Burrowing mammals offer a fascinating avenue for study of speciation of animals with limited aboveground mobility. Among these animals, genetic material transfer is much less universal. Potential mate selection is much more limited. Small subterranean-dwelling mammals are much more likely to be able to achieve some degree of isolation. The effects of natural selection over time become more obvious and significant. Some fossorial animals include North and Central American pocket gophers, African mole rats and South American tuco-tucos. Pocket gophers are basically similar in North and Central America and are nearby real-life examples. In South America, tuco-tucos occupy convergent (similar) habitat niches, spending most of their lives underground. Most tuco-tucos are solitary, although one tuco-tuco species is colonial. Mating probably takes place underground. They construct long and complex tunnel systems which contain chambers for food storage as well as nesting chambers; food is strictly plant parts, mostly roots and stems. Tuco-tucos are named after their vocalization. Tuco-tucos vary in color, though usually with some shade of brown.
The tuco-tuco family is called Ctenomyidae. There is only one genus, Ctenomys, with over 60 described species.* These small mammals are found from southern Peru south to Tierra del Fuego in Chile, with some species in southeastern Brazil, Paraguay, Argentina and Bolivia. One is a newly identified, endangered, species from southern Brazil.**
Tuco-tucos are somewhat problematical to scientists in terms of identifying similarities and differences among the 60 plus described species. Some of the troubling issues faced when researching the various species include presence of varying numbers of chromosomes (26 to 56 but with constant amount of DNA) and differing skull anatomy among the widely distributed 60+ species. Other unique qualities of the tuco-tuco include some with chromosomal polymorphisms (meaning that shapes of chromosomes are not consistent), varying DNA, limited genetic exchange with nearby populations, differences in kinds of occupied habitats, and possible subjection to extreme environmental selection due to differences in soil texture, depth, temperatures.
Many tuco-tuco species have been physically isolated (disjunct) from other population groups for many years. This has resulted in selection and adaptation of some body characters, body function and behaviors in response to the habitat–subterranean niche– “pressures” driving natural selection
A good example of a speciation study is recent research done by Thales, de Freites, Fernandes, Fornel, and Roratto.** They researched a population of tuco-tucos in a rather small area (~ 500 km2 ) in southern Brazil. These researchers obtained a total of 34 specimens, 11 males, 23 females from six known localities. They sampled body tissues and measured skull bone characters and then compared these to known information from other species of tuco-tucos. Primary differences found included chromosome numbers and arms (2n=50; 68 autosomal arms), skull anatomy (morphology), and mitochrondrial cytochrome-b gene. Comparing these, the researchers found that differences were significantly enough from other tuco-tucos so as to merit these a separate species. The new species was named Ctenomys ibicuiensis.
The cytochrome-b analysis resulted in a phylogenetic tree construction indicating all relationships within the genus. Skull size and shape analyses showed C. ibicuencis as having a more compact and smaller skull than nearest neighbor populations of C. torquatus species group. However, the authors state that “chromosomal morphology is the most important diagnostic characteristic that differentiates the karyotype of the new southern Braazilian species,” specifically with a large 1st metacentric chromosome as a diagnostic trait for the new species, supported by geometric morphometric and phylogenetic analyses. The C ibicuencis and C. minutus populations which both have 50 chrpomosomes are very different with the latter having 14 biarmed and 10 acrocentrics.
Systematics, as shown in this example, utilizes different parameters, in concert, to serve altogether as diagnostic rationale for identifying species.
*Eisenberg, J.F. and K. H. Redford. 1999. Mammals of the neotropics, vol. 3. University of Chicago Press, Chicago.
**de Freitas, T.R.O., F.A. Fernandes, R. Fornel, and P.A. Roratto. 2012. An endemic new species of tuco-tuco, genus Ctenomys (Rodentia: Ctenomyidae), with a restricted geographic distribution in southern Brazil. J. Mammal., 93(5):1355-1367.
While at the University of Oklahoma working on a graduate degree, I became interested in pocket gophers (family Geomyidae). These small furry mammals are widespread across the western U.S. into Canada, Mexico and in Central America. One of the most interesting aspects of pocket gophers is their life habit of living in the underground niche. They are rarely seen aboveground. Unless your cat has dragged one home or you have flooded them out of their burrows when irrigating or watering your lawn or field, you probably have never seen one. If you live in western North America, Florida, just east of the Mississippi River or Central America, you have seen their irregularly-shaped dirt “mounds” on the ground surface. As new tunnels are constructed, pocket gophers get rid of excess soil from their diggings by pushing it to the surface. Their overall size varies from the size of a mouse to that of a large rat, depending on where they live. They are solitary and well adapted to living in dark tunnels. They have small eyes, small ears, and sharp claws with which they dig most efficiently— they have no vocalization and are vegetarians.
As is often the case with animals present on one continent occupying a certain ecological niche, there are often counterparts occupying the same niche on other continents. These may have anatomical and behavioral similarities, but are typically unrelated genetically. Biologists call this “convergence.” Similar niche selective factors have resulted in similar (sometimes different) anatomy and behavioral adaptations.
In the Eurasia, the mole-rat (family Spalacidae) occupies a similar underground niche. In South America the convergent underground-dwelling (also called fossorial) small burrowing mammals are called tuco-tucos. Tuco-tucos fill an underground niche and are similar to North and Central American pocket gophers. They are likewise well adapted to underground life. Their adaptations* have resulted in selection for some of the same characters present in their northern counterparts (small beady eyes, small ears, sharp digging fore feet claws, vegetarian food habits, etc). However, there are also differences between them: Tuco-tucos are named for the “calls” or vocalizations they make.** They are more prone to gather vegetation aboveground than their northern continental neighbors. They weigh 100 g. to 700 g. Their fur is typically some shade of brown and they have very short tails.
At the present time, there are more that 60 described species in a single genus, Ctenomys. They are found in a number of South American countries, from southern Peru to Tierra del Fuego: Peru, Chile, Brazil, Paraguay, Uruguay and Argentina in a variety of habitats. Tuco-tucos prefer loose sandy soils, but are not restricted to this soil type. One species (C. lewsi) has aquatic habits and constructs its burrows near streams and water. Often its burrows are filled with water. Another species (C. sociabilis) forms a true colony with interconnected tunnels but this is unusual for the genus.
*Eisenberg, J.F. and K. H. Redford. 1999. Mammals of the Neotropics, vol. 3. University of Chicago Press, Chicago.
**Lord, R.D. 2007. Mammals of South America. The Johns Hopkins University Press, Baltimore.
About Tuco-Tucos (Genus Ctenomys):
Tuco-tucos have exploited the fossorial ecological niche. There are over 60 named species from southern Peru to Tierra del Fuego, Paraguay, Brazil, Uruguay, and Argentina.* Most are solitary and spend most of their lives underground. Gestation length may be as long as 130 days. Young are born with open eyes and fully furred. Litter size is 2 to 4. Mating likely takes place in burrows. Their tunnel systems are long with side chambers containing food storage and nests. Burrows vary in depth from 30 cm to 50 cm, with a diameter of 5 cm. to 6 cm. They feed on roots and grasses. The genus name Ctenomys stems from the fringe of comb-like bristles on the sides of their feet (Cteno = comb; mys = mouse.**
An old book entitled “Camp Lore and Wood Craft”* came into my possession some time ago. The copyright was 1920 and the by-line under the author’s name, Dan Beard, was the following: “Founder of the First Boy Scouts Society.” Having an ongoing interest in Boy Scouting, I shall briefly condense several intriguing outdoor subjects.
Fire-Making, The Pyropneumatic Apparatus.
At about the time of the American Revolution, the “fire ‘piston” was invented. It consisted of a nine inch cylinder, ½ inch in diameter. It ends in a screw which screws on to the magazine and holds some fungus, the tinder. A rod of steel is attached to the plunger (piston) inside the tube. A small hole in the tube allows air to enter and the rod which has a milled head. Lard can be used to lubricate the piston when it is drawn up to the top. A small piece unscrews which allows lubrication. The procedure for starting a fire is to place a small piece of fungus in the chamber, then screw on the top of the piston. Then it is important to hold the apparatus with two hands and place the end on a desk or table, either vertically or horizontally, and then force the piston down as rapidly as possibly. Rapid compression of the air causes the fungus to take fire. As fast as possible, unscrew the magazine, allowing the air to rush in; Dislodge the burning fungus under suitable tinder and nurse it into a flame.
Food Preparation, (Un)Dressing Wildlife
To remove the skin/fur, get a forked branch with the forks about one inch in diameter at whatever height works for you when sitting. The lower end should be sharpened and stuck into the ground. The two forks should be sharpened with the distance between being similar to the width of the animal. Each sharpened fork is inserted into one of the animal’s heels. The first order of business is to remove the skin. Split the skin with a sharp knife from the throat to the tail. Be careful not to penetrate the body cavity with the intestines. At the time the tail base is reached, roll the skin back continuously. When finished, save the pelt. When the skin is completely detached, remove the internal organs and scent glands. Make cuts in forearms and meaty parts of the thigh and remove all the “little white things” which look like nerves. This will prevent cooked flesh from having a musky or strong cooked taste.
How to Harden Green Wood Gluts or Wedges
Old farmers are said to claim that the best wedges are made of applewood or locust wood. Seasoned wedges far outperform green ones. If applewood cannot be found, dogwood and ironwood make satisfactory substitutes. Early American Southern Native Americans used cane to tip their arrows, first slightly charring them with hot fire ashes. Gluts may also be hardened similarly. Heat just enough to force out the sap and harden the surface.
The Etiquette of the Woods—Cooking Porcupines
After a porcupine has been killed, it is best to immediately throw it into a fire to singe all of the quills off. After the quills have been singed off, roll the carcass in grass to make certain the burned quills are rubbed off the skin. Then, it may be skinned with no danger from the barbed quills. With a sharp knife, slit the skin up the middle of the belly to the throat and carefully pull the skin back and peel it off. Cut off the feet. Properly prepared porcupine is indeed a delicacy—but only if it has been boiled in two or three changes of water first. Then, it may be cooked in any way a camper desires.
Beard, D. 1920. The book of camp-lore and woodcraft. Garden City Publishing Co., Inc, Garden City, NY. 2d Ed.
Negative side effects of our present day way of life are wildlife roadkills. With our better and better vehicles which go faster and faster, wildlife often becomes the victim(s). One report states that 253,000 animal vehicle collisions occur annually.* On almost any public roadway, even gravel roads, year around, one often views the mangled remains of a once thriving animal. Vehicles show no mercy, although it is rarely the purposeful intent of the motorist to hit an animal. The result is usually particularly gruesome and one-sided. Several tons of a moving vehicle almost always win in a direct or indirect bodily encounter at any speed. Sometimes one sees deceased larger animals alongside the roadway with no readily apparent fatal damage, though the vehicle that caused it undoubtedly is not so fortunate. However, much more commonly, the squashed body parts of an unfortunate smaller animal lie in the middle of the road. These are run over time and again until there is very little remaining other than some hair/feathers and a bloody stain on the blacktop.
Inadverdant sudden and unforeseen collisions especially with birds and mammals are particularly detrimental to vehicles, also. Repair bills for such run unto the hundreds of millions annually. Human life has been lost on occasion—a tragic, no-win situation for either party.
Although collisions can and do occur throughout the year, they are more common during seasonal migrations, when newborns leaving protective maternal care on their own, or during hunting seasons which tend to disrupt normal game movements. Rural areas seem to be more at risk for wildlife game collisions. Many states place game warning signs along particularly vulnerable migrations routes and movements. However, with numbers of White Tail and Mule deer reaching new population highs in some places, collisions even in urban areas are much more common. I have personally seen Mule deer inadvisedly crossing busy streets in densely populated areas.
The only time I have personally had a “large” encounter was in South Carolina. I was on my way to work early one morning. I saw nothing, only heard and felt a “thud” on the passenger side of my vehicle. Stopping, I found the door had some minor denting and the rear view mirror was markedly damaged. I looked for, but never found, the white-tailed deer that ran into the side of the car, but I assume that it was not injured—probably just scarred, scared and bruised. Living in the West and frequently traveling rural roads, I have contributed my share, but never on purpose, of deadly encounters with ground squirrels, porcupines, skunks, raccoons, and badgers. In no case did any of the latter win the confrontation!
Unfortunately, to my knowledge, science has not yet come up with devices to either warn drivers or animals of impending danger. Some time ago, small “whistle-like” devices mounted on the side of a vehicle were peddled as effective in preventing crashes with deer, but these seem to be mostly ineffective. If there is an “up” side to roadkills, it is this. As a biologist, I keep my eyes peeled for freshly killed animals along the roadway, especially in the early mornings. Biologists are keen to find and report distributional ranges of species of animals, especially small mammals. They inventory local fauna mostly by trapping, or deadfalls. Sometimes, these are not effective in securing a good sampling and so do not accurately reflect local wildlife population presence. At times, rare or exotic animals succumbing to vehicle encounters are a helpful indicator of their presence in places not otherwise documented.
More so in years past than now, biologists first trapped, then prepared “study skins” of local fauna. A study skin is prepared by removing the skin and placing a cotton body with cottoned wire inserted into the limbs and then pinned down to dry. For larger animals, skins only are stretched and preserved. Skulls and bacula (penial bones) are also cleaned and preserved, as sometimes are body tissues. This technique is not taxidermy but is very helpful for future study of taxonomic/systematic characters such as fur coloration, bone structure and measurement, dental details, etc. Special care has to be taken to prevent insect (such as dermestid beetles) damage to the skins. Skin collections in museums, usually universities, house tens of thousand of such specimens and are a treasure house for scientific study
I personally have collected and processed fresh roadkills. I remember sending a red fox skin, salted down, back to the Stovall Museum when out on a prolonged collecting trip. Arriving before the package did, upon opening it, the scent was most rancid and did not help my popularity with the secretaries! I once picked up a fresh badger specimen and temporarily kept it in my parents home freezer. Unfortunately, my mother had a most unpleasant surprise one day and I continued to hear about that for years; in fact, it almost became a family legend!
A discussion of roadkills would not be complete without mentioning the culinary side.* A number of states have legalized the consumption of roadkills, including Wyoming, Montana and Utah. For further information, the internet has a wealth of roadkill discussions.
Robinson, D. 2013. Want a tasty treat? Try a roadkill recipe. Deseret News, March 5, 2013.
I love to fish. From my earliest memories, I have been drawn to fishing as if a giant magnet were pulling me to the nearest stream. Growing up on a farm, I received typical farm jobs and chores around the corral and chicken house and garden all of which all seemed to conspire in keeping me away from the creek.
When I was about six years of age, my dad, who taught FFA in the nearby high school, had a convention to attend in Sun Valley, Idaho. He took the family along, myself, my young sister and brother. I wasn’t able to find a very good daily place to fish—the shallow stream behind tour Ketchum motel didn’t seem to even have any live fish, only several decaying fish someone had caught, cleaned and thrown back into the stream.. One afternoon during the week, after his meetings, Dad took us to the Wood River to fish, a bit, and to see the ski lift. At the time, I had Perthese disease in my right hip and wore a (despicable) brace–which hampered my activity, even though I was able to ride my horse bareback back home.
Dad and I began fishing in the river. I fished from a rocky bank about two feet high, just behind the gravel bar bordering the river. I fished with worms and wasn’t even getting a bite. Finally, I came to a likely looking “hole” where the foamy river water a disappeared under a log and brush jam. I nonchalantly threw my line and worm into the fair-sized hole. I was still on top of the bank, probably some five or six feet from the water. After a few seconds, I felt a pronounced and definite tug on my line. Now, mind you, I had never caught a fish in my entire life, so I didn’t know the finesse means of hooking a fish. I simply did what my reflexes told me, I gave a huge jerk!
Several things then happened in rather rapid succession. First, a “giant” fish came up out of the water at the end of my line onto the gravel bar and began flipping around a few feet from the water. Second, excited, I tripped and tumbled off the bank onto the gravel bar, breaking my pole in fall and awkwardly landing near the flopping fish with my braced leg extending to the water’s edge. Third, the big fish came off the hook and was flipping, flopping back and forth just at the edge of the River. All of this happened in a flash. Fortunately for me–but not for the fish–I had the presence of mind to reach out and corral the fish with my body between it and the river.
The rest of the story is a bit of a blur, now, many years later. I yelled bloody murder and my dad came running. Together, we subdued the big rainbow trout, calling a halt to our fishing expedition for the day and proudly carrying it home to show Mom. A Mr. Richardson took a foto and we weighed it at the grocery store—a five pound, gorgeous Rainbow Trout!
In the intervening years, I have caught hundreds of Rainbow Trout, but none quite so big and none nearly so exciting as my first fish in Sun Valley/Ketchum’s Wood River as a youngster so many years ago.
About Rainbow Trout:
The scientific name for Rainbow trout is Oncorhynchus mykis. It is a good example of an “anadromous” fish species. Anadromous means fresh water fish that reproduce in fresh water with no part of their life cycle in the sea. It is a cool water species, hence not common in deep South warm river systems. Rainbows spawn by laying eggs in shallow nests that the female fish hollows out. Although rainbows have been known to tolerate higher temperatures, they do best in areas where the water remains below 70°F. Eggs are laid in shallow nests fashioned in the gravel of river or creek riffles. The swifter water of riffles allows continuous exposure to oxygenated water, a requirement for developing eggs. About 20 days after being laid, eggs hatch and the fingerlings then begin to fend for themselves. Rainbow trout are carnivorous and feed upon insects, crustaceans, mollusks, annelids and even smaller fish, including their own fingerlings. They are native to western North America into southwestern Mexico. They are a popular sports fish. If memory serves correctly, the world record size for a Rainbow Trout is 40 plus pounds from Flaming Gorge Reservoir (Wyoming) a few years ago.
Most of us think of house mice or brown or roof rats when we think of rodents, often negatively. Why is this? Perhaps it is because these rodents, which have been around as long as human history can tell us, often have been agents of disease which have cost millions of human lives.
However, perhaps it is time to look again at these animals we are prone to despise in a more positive light. For example, in South America, almost half of all named mammals are rodents. There are 16 families, 119 genera, and 497 species.* Their total biomass (weight) exceeds the biomass of all species that prey upon them (snakes, carnivores, birds, etc.). Without rodents, the larger more popular predators which depend on them for food would not exist. They are vital links in earth’s terrestrial (land) and fresh water aquatic ecosystems. Rodents are unique in that they have prominent incisor teeth which serve readily in gnawing functions. They have no corner canine teeth such as those possessed by carnivorous mammals which are so damaging to prey.
The world’s largest rodent is the Capybara, Hydrochoerus hydrochaeris.* The Capybara may grow to four feet in length and up to two feet high. It is semiaquatic, meaning that it has adaptations allowing it to spend part of its daily life in the water. This is helpful in allowing water as an avenue of escape from enemies. Also, water exposure helps it to remain free from mange-causing mites and to keep cool. Some aquatic plants serve as food along with several species of grass.
Capybaras are found from Panama south into northern Argentina.** They are confined to habitats with running water, marshes, estuaries, rivers and streams. Home range size is from 17 to 22 hectares (2.5 acres = 1 ha). Principal predators are the jaguar and anaconda. Capybaras can be nocturnal or diurnal depending on hunting pressure and season. They give a distinctive “woof” bark when alarmed and escape immediately to the water where they are excellent swimmers and potentially are able to remain underwater for several minutes. Leather produced from their hides is popular both in Central/South America and elsewhere.
Capybara’s live in family groups under a dominant male. The male has a harem of females and their young in groups ranging from 10 to 37 in number. Average litter size ranges from one to seven, average of 3.5.*** In nature, infant mortality is about 50 percent, better in captivity (66 %). In some locations, Capybaras may breed twice a year in optimal habitats, but in other places they appear to maintain a single annual schedule of births. The gestation period is 120 + days. Young mature at about the age of 18 months and may live up to 11.3 years in captivity.
Capybaras are a possible reservoir for brucellosis. They are often infected with Trypanosoma evansii, a disease found in horses. They are susceptible to several species of mites but these are controlled by morning mud baths. Drying follows in bright sunlight; mud is then removed by water bathing. Also, Capybara’s may become infected with a bacterium which causes swelling of the throat, also common among some other rodents, and usually leads to death.
Capybaras do scent marking.**** They have scent glands in their snouts and in the anal area that seem to be mostly connected to aggressive interactions. Most marks are deposited without any obvious reason. Males scent-mark more often than females. *Lord, R. D. 2007. Mammals of South America. The Johns Hopkins University Press, Baltimore.
**Eisenberg, J. F. and K. H. Redford. 1999. Mammals of the Neotropics. The Central Neotropics, Vol. 3. The University of Chicago Press, Chicago.
***Chapman, C. A. 1991. Reproductive biology of captive Capybaras. J. Mammal., 72(1):206-208.
**** Herrera, E. A. and D. W. Macdonald. 1994. Social significance of scent marking in Capybaras. J. Mammal. 75(2):410-415.
I grew up in a small Idaho farm town. I grew up enjoying wildlife. In the early days, I hunted English sparrows with a single shot BB gun I borrowed from my grandparants who lived only a couple of blocks away. Some of our neighbors hunted for larger game in the nearby mountains during the fall season. I envied them! Although there were undoubtedly larger game in the national forest further up the nearby canyon, I can never remember spotting elk or moose in those early days. The latter are much more plentiful and visible today. In those days, my summer jobs were boring enough—getting up, milking several cows, delivering about 30 daily newspapers on my faithful palomino horse Bonnie, trailing the cows to the field pasture about two miles away, hoeing weeds in the garden or going out to the fields and helping my dad with ditching. Digging out heavy sod from the ditches has to be the hardest work in the whole world—I disliked it, but in later life came to realize that here it was where I truly learned the meaning of work! How I looked forward to being old enough to hunt!
In October, when many of the year’s crops were already safely tucked away for winter, mule deer season opened. The air was nippy by then and the ground was sometimes covered by frost in the early mornings and sometimes snow. However, on most days the sun warmed things up, making it somewhat pleasant. When I was finally 14, I purchased a hunting license. I had no rifle of my own nor did my dad who was constantly working to support our family of nine. So, I borrowed a 30-30 from a clerk at a neighboring hardware store in the next town over. With my saved newspaper money, I purchased a box of twenty 30-30 shells. I found an old red sweatshirt and I was ready to go!
One brisk October morning, Dad gave me a ride up the nearby canyon into the national forest. The area was mountainous with abundant pine and quaking aspen trees. Deciding to go south, I crossed the creek by balancing on a log and walked slowly up a nearby mountainous “hollow” (or draw or ravine). There was still frost on the grass and small shrubs. The steep trail was difficult to negotiate as there were many larger rocks that had to be climbed over, walked in between or completely detoured around. Fallen trees further challenged me. After about an hour and a half or so of climbing, the draw opened up at the top into a plateau-like sagebrush covered flat bordered by pines.
I walked through part of the flat, sometimes through mud, up one side of another draw, climbing through pines in an easterly direction. There were occasional larger rocks and a stray sunflower, now with most or all of the bright yellow petals gone with only the black seed head remaining. Every now and then I pulled one of the seed heads from its stem and tossed it absently to the side. Though I tried to be very quiet, no deer were heard or seen, although there were plenty of tracks. By now, the sun had burned off most of the preceding night’s frost, but the ground was dry for the most part. After another half hour, the hollow, which I later found was called the Overland Trail, crested on a ridge and dropped down into another draw oriented downhill and to the east. Seeing nothing, I sat down on a smooth limestone rock and rested awhile, perhaps even dozing a bit. Awhile later, I pricked up my ears as I thought I heard something walking through an area almost completely covered with rocks several hundred yards to the north, “Clip clop, Clip clop.” I followed the sound with my ears the best I could even though the tree cover masked whatever was making the noise. Now standing up and looking around me, again, in a few moments, I looked downhill from where I had just climbed. There I saw two huge mule deer bucks, both with large antlers ambling parallel to the my ridgetop along the forested hillside towards the South probably about 100 yards away.
I had heard seasoned hunters say that when one is about to shoot at his first deer, a severe case of “buck fever” often occurs; that is, one begins to shake with excitement to the extent of not being able to shoot accurately. This time, such was not the case with me, however. I cocked the old rifle by pulling back on the external hammer, sighted through the iron sights at one of the bucks and shot. I had heard from seasoned hunters that when one is shooting downhill, the trajectory of the bullet tends to be a bit high and when shooting uphill, one needed to shoot a little high. Did I miss? I hurridly worked the lever to throw another bullet into the chamber of the old 30-30. I stood perfectly still, as one of the bucks came running uphill almost directly towards me. Apparently the sound of the shot alarmed him to the point that making a fast exit was quite important. The only problem he had was that he had no idea where the shot originated. As the buck ran closer and closer, I aimed and finally pulled the trigger from a distance of a mere 13 paces—and the buck dropped. Checking to verify that my shot had been well placed—I found that it was.
Then, I did the necessary cleaning and gutting. I used my hunting knife that I had proudly buckled on in front of my siblings earlier in the day. I was by this time quite thrilled of getting my first deer. I still don’t know where the time went, but it was late afternoon by the time I convinced myself that I couldn’t drag the large 150 pound plus animal down the mountain by myself. It was very heavy. So, I retraced my steps down the draw to the ravine to the canyon road and then walked or hitched a ride down the the seven miles of dirt and graveled road to my home, arriving about 6 p.m. I excitedly told my dad, and after a fast meal, the two of us returned up the canyon, hiking to the deer just as darkness closed in on us. We cut the deer in half and then made the huge mistake of attempting to drag it directly down White Rock Mountain to our vehicle in the canyon below. The mountain was well named, as there were huge white rocks twice the size of a man scattered along its sides. We struggled with that half deer, handing it back and forth as one would clmib through through a tight place or steep place past the huge boulders in pitch black darkness. After several hours of struggling, we finally reached the bottom of the mountain. At least we were warm in the bitter October breeze due to our exertions. We arrived home about midnight. I was so tired that Dad had to milk the cows.
The next day, I related our story to a good family friend. He instructed me to saddle up my horse, bonnie, and together with his horse loaded in his stock truck, we drove to way further up the canyon than I had been the day before. We then rode our horses up a fairly good zig zag trail to reach the top which turned into the same flat as I had encountered before, though further west. I was pretty worried about being able to locate my deer. What would I do if I couldn’t find it? But, fortunately, I was able to locate it. We loaded it onto my horse and we were able to arrive home in good time. In the East, my buck would be an “Eight Pointer;” however, in the West, it was a “Four Pointer.”
For many years, those antlers with four forks on either side graced my bedroom’s wall in the second floor of our old Idaho brick farmhouse.
About Mule Deer or Black Tailed Deer
Mule deer (Odocoileus hemionus) are readily identified by their large, independently twitching ears. They are usually shades of brown with some white in coloration. They are heavier in build than are their eastern White Tailed Deer relatives. Mule deer are primarily found west of the Mississippi River in North America, while White Tails are common in the East. There are extensive areas of distribution overlap between the two species. Mating season occurs in late fall. One to three fawns are born, the average being two. Does take exceptionally good care of their young for almost a year. They often secrete their fawns and return at long intervals to nurse them. Bucks tend to remain in groups during the winters. Mule deer are active at dawn, evening and even during the night time. They feed on browse, shrubs, and bushes. They prefer broken country, partially wooded terrain and are rarely seen in swampy area.
A number of species of small rodents (mammals) live in the Great Basin desert such as the kangaroo rat in the photo above. They are mostly nocturnal, meaning they are active during night-time. The furs of most are variations of brown, white, and gray camouflage in austere areas of limited vegetation. The Great Basin is an arid desert area mostly in the western U.S. states of Idaho, Utah, Nevada and Oregon. In these desert areas, there is little water and scarcity of vegetation. Plants serve as food sources and provide cover. Vegetation cover allows small animals to hide from their natural enemies (predators) including foxes, coyotes, owls, bobcats and snakes.
Small desert rodents have a dilemma. They must be able to acquire sufficient food in order to obtain the adequate energy levels required for life. However, they must be careful of how to use this limited, hard-earned energy. Energy uses/costs include reproduction, searching for a mate, while at the same time being constantly on the lookout for predators. In bright moonlight, they become more likely to become prey victims. In order to minimize the risk of becoming a ”snack” for a hungry enemy, the question is to whether sm
all, nocturnal, desert rodents actively avoid moonlight?
N. Upham and J. Hafner* researched 62 study sites across the Great Basin during 69 nights over a period of seven years. Twenty species of nocturnal (night-active) rodents were live trapped during the study. The kangaroo mouse (Microdipodops), called an “obligate sand dweller,” was used as an indicator of typical (sandy) desert habitat. Rodent activity during clear moonlight nights was compared to activity during various other moon phases and brightness.
Results of the study showed that different Genera (kinds) of rodents responded differently to moonlight. Only one genus, Dipodomys–kangaroo rats, showed significantavoidance activity to bright moonlight in summer seasons (but not during spring or fall seasons) compared to lesser brightness of other moon phases. This may be a specialized trait of kangaroo rats as compared to general behavior of other nocturnal Great Basin desert species.
The researchers found that the activity of deer mice (Peromyscus), pocket mice (Perognathus), and kangaroo mice may be more influenced by competition for food with kangaroo rats than with variations in phases of moonlight. The variables of body size, locomotion, and space use by kangaroo rats may be important in contrasting moonlight responses–if these influence how other rodents evaluate the risk dangers of bright moonlight.
*Upham, N. S. and J. C. Hafner. 2013. Do nocturnal rodents in the Great Basin Desert avoid moonlight? J. Mammalogy, 94(1):59-72.
In the present world’s turmoil, some would ask one or more of the following questions:
“Is there a God in heaven?”
“If so, does God know and love me?”
“Why doesn’t God communicate with man any more?”
“Each year, I see my life slipping away as I get older, yet I feel no closer to God. What do I need to do to bring him into my life so that I can be prepared to meet him before I die?”
“I have my freedom of choice in regards to choosing a religion and my personal beliefs. Can I use the Bible as a guide in finding and choosing God’s truths today among the thousands of religious organizations that profess to be his?”
God lives. He is our spiritual father and he knows us each by name. He loves each of us. He is aware of the choices we make, good and bad.
In order to know his will, one needs to seek it through humble prayer; this means each of us needs to find a secret place to communicate often and regularly by praying and asking for his help. All of us draw nearer to God by asking. If we don’t ask, it is pretty certain he may not answer. How should one pray? Begin by addressing God, our heavenly Father, then give thanks for many blessings, then ask for special help or assistance with any problems or questions, then close in the name of his Son (See the Book of James in New Testament, chapter 1, verses 5-6). He will surely answer— but in his own way and in his own time.
Look for answers to questions in the holy scriptures by reading them each day. The Bible is treasure house of spiritual wisdom.
If one is serious about finding God’s truth and his actual living prophets who receive revelation, today, one just needs to ask… and keep asking. If one is humble and truly sincere, an answer will be sent as surely as the sun rises in the mornings. It may not be immediate, but it will come if one is sufficiently humble and sincere. Most likely, one will not hear a voice or see a vision. However, be prepared and sensitive to be able to recognize spiritual impressions and feelings of peace when they come. This is the most common way of Heavenly Father’s communications to his children.
E. Blake Hart