Wildlife of the Prairies
The gravelly outwash prairies of South Puget Sound provide habitat for several species that are rare and in danger of extinction. All of these species show evidence of decline, with multiple threats to their existence still prevalent. The most common threats include introduced plants such as Scotch broom, land development, incompatible agriculture, and the succession of prairie landscapes to forest. As prairie habitat disappears - through conifer encroachment and human activities - so will these species that are living clues to our region’s geological and ecological history.
Mazama Pocket Gopher (Thomomys mazama)
Mazama Pocket Gophers are rodents that spend most of their lives underground, and are particularly well-adapted for burrowing. They have short, strong legs, and small ears and eyes. Their lips can be closed behind their front incisors, which the gophers use for burrowing. Their soft, loose pelts enable them to move backwards through their tunnels as easily as they move forwards. Each pocket gopher also has two, fur-lined check pouches extending from the lower portion of its face to its shoulders. These pouches are used to transport food, and can be turned completely inside out.
Pocket gophers feed on roots, bulbs, tubers, and the leafy portions of plants. They often forage by biting off a plant’s roots, and then pulling the entire plant down into the burrow from below. This strategy helps limit time spent above ground. Pocket gopher burrows are usually marked by a series of earth mounds. Unlike mounds created by moles, which are volcano-shaped, pocket gopher mounds are fan-shaped. Pocket gopher burrows have separate chambers for food storage, nests, and waste.
In western Washington, several isolated populations of pocket gophers have evolved into separate subspecies. Some of these subspecies are already extinct, and the rest have become rare. Habitat alteration, the use of traps and poisons, and predation by domestic pets, all take their toll on this species. The Mazama Pocket Gopher is a State Threatened Species and is a Federal Candidate Species [PDF]. Learn more about the Mazama Pocket Gopher here or look at the Washington Department of Fish and Wildlife's pocket gopher FAQs here [PDF]!
Streaked Horned Lark (Eremophila alpestris strigata)
Horned larks can be found in a variety of open areas from agricultural fields of eastern Washington to above the tree line in the mountains. The Streaked Horned Lark resides only west of the Cascades at low elevations, from southern British Columbia to Oregon and is the rarest bird in western Washington. This small, ground-dweller has dark tufts of feathers on the back of its head. It has a brown back and neck, yellowish under parts, and a yellow eyebrow stripe and throat. In fact, the bright yellow color of the streaked horned lark helps distinguish it from other lark subspecies, but it may also make observations in the field harder by reminding one of meadowlarks, another prairie bird.
Horned larks prefer sparsely vegetated prairies and agricultural land with short vegetation. These birds forage for seeds and insects on the ground. Horned larks form nomadic foraging flocks during fall and winter, but establish territories when breeding. Its nest consists of a depression on the ground, lined with fine plant fibers woven with soft material such as feathers, fur, and rootlets. This lark most often sings in flight, circling slowly on fluttering wings so high in the sky that it can be difficult to spot. Less commonly, it will sing from high points on the ground. Its primary song during the breeding season is a lengthy series of tinkling notes that seemingly come drifting down from the far reaches of the sky.
Historical evidence suggests that this subspecies has declined considerably in abundance since the days when prairies were more extensive in western Washington. The Streaked Horned Lark is a State Endangered Species and a Federal Candidate Species.
Taylor’s Checkerspot (Euphydryas editha taylori)
This black, white and orange patterned Checkerspot is one of the more colorful prairie butterflies. It occurs in the Puget prairies and the maritime prairies along the Straits of Juan de Fuca and the San Juan Islands, down through the central Willamette Valley. Taylor’s Checkerspot is a sub-species of the Edith’s Checkerspot. Two additional subspecies, occurring in California, are listed as federally endangered.
Taylor’s Checkerspot is a springtime flyer, and can form spectacular displays of hundreds and even thousands of individuals on a single prairie. The Checkerspot host plants include the native paintbrush and introduced plantain. It uses a variety of species as nectar sources, including camas, balsamroot and spring gold.
While Taylor’s Checkerspot has disappeared from multiple prairies, a program to bring them back is underway. This program includes captive rearing of Checkerspots at the Oregon Zoo and release into protected prairie sites in the South Sound area. The program has shown initial success, with breeding butterflies surviving for several years. Hopefully soon South Sound prairies will again be filled with Checkerspots.
Taylor’s Checkerspot is a State Endangered Species and a Federal Candidate Species.
Mardon Skipper (Polites mardon)
This small, orange butterfly occurs on two South Sound prairies and can also be found in the southern Cascades, where it inhabits ridge tops and other openings within Ponderosa Pine woodlands. The Mardon Skipper has been found in less than ten locations in Washington. On the prairies it depends upon Roemer’s Fescue (Festuca roemeri) as a larval host plant, and uses a variety of spring-flowering nectar sources, including the Western Blue Violet (Viola adunca). The Mardon Skipper is a State Endangered Species and Federal Candidate Species, and exists primarily in Washington, as well as, Oregon and northern California.
Western Gray Squirrel (Sciurus griseus)
The Western Gray Squirrel is the only native, large tree squirrel occurring in its range along the West Coast region. It is gray with numerous white-tipped hairs on its back and a white belly. The backs of its ears are a reddish brown, and it has a long, bushy tail with bands of gray, white, and black, especially noticeable along the tails underside. This species remains active year round, though during particularly bad storms it may seek shelter in its nest. In summer it uses a nest of shredded bark and sticks, usually placed at least 20 feet above the ground; in winter, it most likely lives in a tree hollow. This gray squirrel feeds primarily on pinecones, acorns, and other nuts, and will eat some fungi, berries, and insects. This squirrel's hoarse barking call is heard mostly in the late summer months.
The Western Gray Squirrel has been found in three areas in Washington State , including on Joint Base Lewis-McChord in the South Sound region. It relies heavily on the oak prairie woodlands, a habitat that is under assault from population growth and development. This loss of habitat has drastically reduced the number of Western Gray Squirrels in the state. This squirrel is a State Threatened Species.
Additional Rare or Declining Prairie Wildlife
Additional rare and declining birds in the prairies include the Oregon Vesper Sparrow, Western Meadowlark, and Northern Harrier. But not all birds are declining. One notable conservation success is the Western Bluebird. Bluebirds are a common sight on the prairies due to a successful bluebird nest box program that started on Joint Base Lewis-McChord. Bluebirds from Joint Base were used recently to reintroduce the species back to San Juan Island. During the spring and early summer, don’t miss the WA Dept. of Fish and Wildlife’s bluebird cam.
The Slender-billed White-breasted Nuthatch (Sitta carolinensis aculeata) is a western Washington subspecies that is very local, rare and seriously declining. It was associated with oak and oak-conifer woodlands in the southern Puget Trough and occurs only in Washington on the Vancouver plains in Clark County.
Several unique butterflies are restricted to Puget prairies. Each prairie will have a unique assemblage of butterflies, that may include the Zerene (or Valley) Silverspot (Speyeria zerene bremnerii) or the Oregon Branded Skipper (Hesperia comma oregonia). Puget prairies are also a preferred habitat of one of our largest butterflies, the Puget Sound Silverspot (Speyeria cybele pugetensis). The delicate Puget Blue butterfly (Icaricia icarioides blackmorei), occurs only the South Sound and Sequim prairies in Washington. It is a State Candidate Species.
Two reptiles, the Pacific Gopher Snake (Pituophis melanoleucus catenifer) and the Racer (Coluber constrictor), have been extirpated from the prairies while the Sharp-tailed Snake (Contia tenuis) and the Western Fence Lizard (Sceloporus occidentalis) are declining. The Western Pond Turtle (Clemmys marmorata) and the Oregon Spotted Frog (Rana pretiosa), both state endangered species, are associated with prairie wetlands.
Creating a home for the Oregon spotted frog
Occurring only in the Northwest, the Oregon spotted frog appears to have been extirpated (made locally extinct) from more than three-quarters of its former range. Historically, these frogs found the habitat they prefer – open water with some shallow areas and aquatic plants – in the flood plains of larger bodies of water. As humans have controlled flooding and introduced invasive species, suitable habitat has decreased.
Conservationists at the Center for Natural Lands Management (CNLM) are working to create and maintain suitable habitat for this frog, a candidate for listing under the federal Endangered Species Act. At Mima Creek Preserve, a conservation area adjacent to the Black River owned by the Nature Conservancy and managed by CNLM, conservationists created five acres of open water ponds and planted native emergent vegetation on what was formerly agricultural or grazed lands. CNLM also works to protect the open water areas from invasive species such as reed canary grass, which can quickly encroach on the ponds.
So far, monitoring indicates the area is a magnet for many native amphibians and reptiles, in addition to other wildlife, although no Oregon spotted frogs have yet been sighted. CNLM plans ongoing monitoring of all amphibians and reptiles and hopes one day to release captive-reared Oregon spotted frogs into the area if they do not return of their own accord.