The first time I ever saw the Sandhills, I was mesmerized by the rolling green hills dotted with various wildflowers. Like the diverse blend of plants that make up the Sandhills of Nebraska, the ecoregion also hosts a large variety of mammal species typically found in both the mesic (moister) tallgrass prairie and the more xeric (drier) shortgrass prairie. Historically the most conspicuous mammal species was the American bison (Bison bison), which currently are found only in managed herds in Nebraska. Now the most visible large grazers are domesticated cattle (Bos taurus) and four species of wild ungulates: pronghorn (Antilocarpa americana), elk (Cervus canadensis), mule deer (Odocoileus hemionus), and white-tailed deer (O. virginianus).
But it’s the inconspicuous mammals that help make the Sandhills such a unique ecoregion. A great example of a rarely seen mammal is the least shrew (Cryptotis parva). The scientific name of this species means “hidden ear, small,” an apt name given the shrew is rarely longer than 3.5 inches and weighs about 5 grams, the same as a nickel. As for those “hidden ears”? These shrews have two small ear holes, but they are well hidden beneath their short but dense fur. Despite its small size, the least shrew adds immense ecological value to the Sandhills by engaging in “nutrient cycling”—digging burrows, consuming invertebrates (e.g., insects, worms, spiders, etc.), and moving organic and inorganic matter throughout its range. Nutrient cycling is necessary for any ecosystem to maintain itself because it allows species to survive within that ecosystem.
A slightly easier nutrient cycler to see is the charismatic (in my opinion), nocturnal sand-loving rat called Ord’s kangaroo rat (Dipodomys ordii). Where there’s open sandy soil you’ll find these rats hiding in their burrows during the heat of the day and foraging for seeds in the cool evenings. Ord’s kangaroo rat (and several species of mice in the Sandhills) belong to the family of rodents called Heteromyidae (different mouse); likely named so because this group of rodents has evolved several physical and physiological adaptations to survive in drier climates. The most obvious of these adaptations is the fur-lined external cheek pouches in which they carry seeds back to their burrow. Having external cheek pouches likely prevents unnecessary moisture loss as the seeds are being taken in and out of the pouch. Kangaroo rats are so well adapted to life in hot, dry climates that they don’t drink water; all the water their body needs comes from the seeds they collect. And their highly efficient kidneys concentrate their urine so no bit of water is wasted. A more common Heteromyidae in the Sandhills is the plains pocket mouse (Perognathus flavescens), a small nocturnal mouse that is thought to be very common in the region, but in a casual visit to this ecoregion you’re not likely to see either species unless you know to look for them.
The northern grasshopper mouse (Onychomys leucogaster) is also a common Sandhills rodent. These mice are more commonly found in disturbed areas, shortgrass prairie, or grazed rangelands where there are plenty of insects, lizards, snakes, and other small mice for them to eat. Unlike the previously mentioned species, the northern grasshopper mouse’s diet is largely carnivorous, and depending on the season only about 25 percent of their diet is plant material. Some authors have noted an association between this mouse and the black-tailed prairie dog (Cynomys ludovicianus, another once-common species in the Sandhills) as they both like areas with short vegetation so they can see predators on the approach.
The thirteen-lined ground squirrel (Ictidomys tridecemlineatus) also prefers shorter vegetation; however, two other species of ground squirrel occupy the Sandhills from opposite sides of the ecoregion. The spotted ground squirrel (Xerospermophilus spilosoma) is found in dry, sandy soils with sparse vegetation and ranges all the way from Mexico to southeastern Wyoming; its most northeastern range is the Sandhills of Nebraska. This species is well adapted to the xeric environments it inhabits, unlike the third species of ground squirrel found in the Sandhills: Franklin’s ground squirrel (Poliocitellus franklinii). Franklin’s range from Illinois and Wisconsin east to the Nebraska Sandhills and then north into Canada. Contrasting the previous two species of ground squirrel, Franklin’s prefers the ungrazed areas of mixed-grass and tallgrass prairie where there is plenty of vegetative cover for eating and hiding from predators. And yet all three of these ground squirrels are able to find suitable habitat within the Sandhills not only because of the region’s size but because of the wonderful variation within the ecoregion.
The Sandhills also contain wetlands and forested riparian areas that attract species different from those who inhabit open grasslands. These include many of the common species you’ll find all over the Great Plains, like beavers (Castor canadensis), white-footed and deer mice (Peromyscus leucopus and P. maniculatus, respectively), opossums (Didelphis virginiana), and of course the only mammals capable of true flight: bats. Common bat species include the big brown bat (Eptesicus fuscus), eastern red bat (Lasiurus borealis), hoary bat (L. cinereus), and the silver-haired bat (Lasionycteris noctivagans).
All these smaller mammals also play a role as food for the carnivores that call the Sandhills home. Again, there are several species that are common throughout the Great Plains, and you’ve likely heard of them before, like badgers (Taxidea taxus), bobcats (Lynx rufus), coyotes (Canis latrans), red foxes (Vulpes vulpes), and striped skunks (Mephitis mephitis). But there are also a few species you don’t hear about as much, like the long-tailed weasel (Mustela frenata). These powerful hunters only weigh about a third of a pound but are known to kill prey larger than themselves by giving them a strong bite on the neck, right at the base of the skull.
A final mammal that is likely still found in the Sandhills is the eastern spotted skunk (Spilogale putorius). Much smaller than their striped counterparts, eastern spotted skunks once inhabited much of the eastern United States, but in the 1950s their populations declined sharply across their entire range. One place we occasionally still see this species in Nebraska is the Sandhills, but we don’t know for how much longer.
The Sandhills is such a distinctive ecosystem and contains a truly unique combination of mammals—all of which should be experienced and appreciated by everyone.