Mammals of the Rio Bosque

Ondatra zibethicus

escape predators. ascend trees to forage or They’ve been known to Foxes are good climbers. Bosque. Surprisingly, Gray seasonally abundant at the Rio and fruits like wolfberries that are wide variety of insects, birds, eggs, park. They round off their diet with a and rats, several species of which inhabit the at the same time as their chief prey, nocturnal mice of the Gray Fox. Foxes are generally active down the middle – this is a distinguishing feature long, bushy, black-tipped tail with a black strip If you’re lucky enough to see a fox, look for its Urocyon cinereoargenteus Gray Fox young birds. been known to eat clams, crayfish, fish, frogs and seen out and about during the day, and they have nocturnal vegetarians, but they are occasionally sticks and leaves. Muskrats are primarily lodges out of heaps mud piled with cattails, underwater entrances. They can also construct banks of water courses and make dry dens above Like the local beavers, muskrats burrow into be distinguished by its long, black, rat-like tail. muskrat is smaller than the beaver and can easily Another rodent adapted to an aquatic lifestyle, the Muskrat

Browse Line browsing. and grazing jackrabbit the absence of the Rio Bosque’s vegetation develops in These exclosures will allow us to study how were fenced to exclude these animals. large areas in the north part of the park installed to discourage jackrabbits. Two some of the plantings in upland areas were the park. The wire cages you see around the main cause of scarcity grasses in highly effective mowing machines, probably a jackrabbit can reach. Jackrabbits are also new growth survives only above the height shrubs have a distinct “browse line” where like four-wing saltbush and wolfberry. Many browse on the foliage and shoots of shrubs at the Rio Bosque. Black-tailed Jackrabbits structure and composition of the vegetation Humans aren’t the only ones influencing Shaping the Landscape

(Sigmodon hispidus), a common On the Cover: Hispid Cotton Rat rodent active at night in the Rio Bosque. open to all people without regard race, color, sex, Educational programs of the Texas Forest Service are disability, religion, age, or national origin. www.cerm.utep.edu/riobosque/ call Find out how you can participate: community involvement for success. The Rio Bosque project relies on Friends of the Rio Bosque, El Paso, TX. ©2004 by the Epson El Paso. Printing generously provided by Illustration by David Nakabayashi Edited by John Sproul Text by Maria A. Trunk administered by the Texas Forest S by a USDA Urban Forestry Grant Brochure Series was made possible The Rio Bosque Educational found in our river valley. of the unique and valuable ecosystems once working to bring back meaningful examples in a new way. Here, is a diverse partnership Park, the environment is still changing, but are virtually gone. At Rio Bosque Wetlands productive natural habitats, but today they Norte region. They were the area’s most the banks of Rio Grande in Paso del Wetlands and riverside forests once graced 915-747-8663 or visit ervice.

El Paso, Texas Park Wetlands Rio Bosque MAMMALS of the Rio Bosque Desert Cottontail Beaver Sylvilagus audubonii Castor canadensis Smaller than jackrabbits, cottontails are less Before the Rio Grande was dammed and commonly seen at the Rio Bosque because they channelized, beavers were fairly common in the No matter what time of year you prefer to feed at dawn, dusk or throughout the El Paso area. The broad river was unsuitable for visit Rio Bosque Wetlands Park, night. Desert Cottontails wait out the heat of the construction of beaver dams and lodges, so the chances are pretty good you’ll day under cover; some have been known to climb large rodents burrowed into banks, making trees or hunker down in the burrows of other underwater entrances that led up to snug, dry dens. catch a glimpse of a Black-tailed animals. Cottontail young are born blind and The surrounding riparian forest provided abundant Jackrabbit. The rest of the park’s helpless, but they develop quickly. Females can cottonwood and willow trees for food. As the mammals are encountered more breed at 80 days old. Cottontails are staple prey character of the valley was altered, beaver habitat rarely. Most are secretive or active for many other desert dwellers like hawks, and populations declined. Today these supremely only at night. If you look carefully, rattlesnakes, bobcats and foxes. adapted aquatic mammals are found only in however, you’ll find many signs of irrigation canals and refuges like the Rio Bosque. mammal activity: tracks, scat, burrows and nibble marks are all around. A complete list of mammals whose presence has been verified at the park is available at the Visitor Center.

Black-tailed Jackrabbit Lepus californicus Beavers are chiefly nocturnal. Despite the name, a jackrabbit isn’t a rabbit – it’s a They are covered with dark, thick hare. Unlike rabbits, hares are born with full fur fur except on the paddle-shaped Spotted Ground Squirrel tail, which is scaly and serves as a and eyes open. They can hop along with their Spermophilus spilosoma mothers soon after birth. In a short time, young rudder for maneuvering under water. jackrabbits become expert runners: some have been Unlike most rodents, members of the squirrel Their rear paws are webbed to help propel clocked moving as fast as 40 miles per hour. family tend to be active during the day. The Rio them when swimming. Beavers can stay Bosque’s representative from this group submerged for as long as 15 minutes thanks to Their most prominent features, those long ears, help occasionally can be found sitting on its haunches, their ability to reduce their heart rate and tolerate jackrabbits detect predators. They also perform prairie dog style, near the entrance to a burrow. sizeable buildups of carbon dioxide in the blood. another very important function: packed with blood Spotted Ground Squirrels feed on green Beaver teeth make very effective tools for vessels, the ears act as radiators for the animal, vegetation, seeds and insects. Their back fur is gnawing the bark off trees. Many of their favorite allowing up to one-third of the body heat to escape. tan, blending in with the soil color, and randomly food species that have been planted at the Rio Look for jackrabbits in the upland, more sparsely- spotted with white. Their belly fur is white and Bosque are encircled with cages to protect the vegetated areas of the park. their tails are small, not bushy, with a darkish tip. young trees from hungry beavers.