With its forest, water and meadow habitats, Rock Creek Park is home to a wide variety of creatures. Over time, they have ranged from ancient mastodons and Colonial Era bison to recent coyote sightings.
For its first human visitors, Rock Creek was not quite a Jurassic Park. But the ancient American Indians who camped in the area did hunt big game ranging from mammoths, mastodons and musk oxen to caribou, wolves, beavers, lynx, moose and black bears.
Early colonial settler Henry Fleet wrote in 1631, "As for deer, buffaloes [sic], bears, turkeys, the woods do swarm with them." As more people came to the Rock Creek valley to live and establish farms and mills, many species declined or disappeared.
By the late 1800s, Thomas Blagden—one of the valley's primary landowners—fenced in 20 or 30 acres to create a "deer park." The does and bucks he raised were by then such a novelty that Washingtonians rode up from "the city" to see them.
Unlike the deer, those bears and bison have yet to make a comeback along Rock Creek—except at the National Zoo. But hundreds of species of animals are now at home inside the city thanks to the Park's protected habitat.
The forests provide shelter, food and nesting sites for numerous bird, reptile and mammal species. The woodlands shade the wetlands, keeping the water cool and welcoming to amphibian communities. Tree branches provide an important resting spot for tropical birds heading south for the winter or flying north to breeding grounds. Meadows and recreation areas supply habitats for other animals and insects.
Meet Your Mammals
Today, 30 species of mammals live inside the Park, most commonly whitetail deer, raccoons, red and gray foxes, squirrels, chipmunks, shrews, moles, voles, mice, rabbits, beavers and—since their first confirmed sighting in 2004—coyotes. The presence of coyotes provides another reason to follow Park regulations and keep your dog on a leash.
But we can also thank these newcomers for eating a lot of rats and mice—and they may help the Park's own conservation efforts aimed at decreasing the deer population from today's dangerous levels.
The deer are eating so many tree seedlings and feasting on so much of the understory of non-woody plants that the native forests can't regenerate, the environment is losing its native shrubs and wildflowers, and other animal species are finding their habitats greatly reduced.
Another notable Park mammal is the black squirrel. While no zoo today would release non-native species into the surrounding environment, the black squirrels we see scampering throughout the DC area are all descendants of a small group of Canadian squirrels housed at the National Zoo and let out on purpose in the early 1900s.
Creepers and Swimmers
The Park's most familiar reptile species include various snakes, turtles, skinks and lizards. The most common amphibian is the redbacked salamander. There are also more than 160 species of birds living in or migrating through the park, and nearly three dozen varieties of fish.
You should be seeing those fish in greater numbers now that they can reach spawning grounds upstream. Carefully placed boulders have created natural-looking rapids that allow fish to swim beyond sewer pipes and other obstacles. And the concrete fish ladder that opened in 2007 helps herring, shad, alewives, striped bass and other species get around the old ornamental waterfall at Peirce Mill. Perhaps Rock Creek will again experience the massive spring fish migrations of centuries past.
Rock Creek Park still contains several dozen seeps and springs, the remnants of a larger system that used to provide the city with much of its best drinking water. These freshwater habitats offer a home to some rare animals, including the only endangered species believed to live in the Park. The Hay's Spring amphipod is an eyeless, colorless crustacean less than an inch long that looks like a shrimp.
Sights and Sounds
Some of the Park's greatest pleasures come from witnessing wildlife—seeing the red streak of a fox running across your path, viewing fish from the bank of the creek, happening upon a painted turtle or wood frog. Other joys come from noticing the sounds of birds calling to each other, the rat-a-tat of woodpeckers boring into tree trunks, the chirps and cadences of crickets and cicadas.
An event in May 2007 focused on experiencing as many of the animal (and plant) species as possible in a single 24-hour period. BioBlitz, sponsored by the National Park Service and National Geographic, offered a snapshot of the rich variety of life in Rock Creek Park. Volunteer naturalists hurried to identify as many species as possible in just a day, counting more than 650 different kinds of plants and animals. The total included 15 species of mammals, 82 kinds of birds, 23 fishes, 15 amphibians and reptiles, 16 aquatic invertebrates, 28 terrestrial invertebrates and 154 insects.
How many can you find during your next trip down a Rock Creek trail?