Saving on the by Martha Balis-Larsen and Karene Motivans Brink of Extinction

According to paleontologist Niles Eldredge, Earth is experiencing its sixth major wave of extinction.1 Our nation has not escaped the forces threatening plant and species. Of the more than 1,200 species in the United States currently protected by the Endangered Tan riffleshell Species Act, 417 are declining in number and 28 others Photo by Richard Biggins/USFWS are now believed to be extinct. Many critically endangered species are geographically concentrated in “hot spots.” What’s in a name? Aquatic species in the Southern and supporting sustainable develop­ The common names for many Appalachian and Lower Tennessee ment and resource use that also critically imperiled species Cumberland ecosystems. The south- conserves the species. identify the areas that sustain eastern U.S. has the greatest diversity of Endemic Hawaiian plants and them: Tumbling Creek cave snail, sturgeon, freshwater mussels and crayfishes in . Hawaii has more critically Laguna Mountains skipper, the world, and the highest diversity of endangered species than any other Shasta crayfish, Rio Grande freshwater fishes and snails in the state. As of October 24, 2003, there are silvery minnow, Sonoran country. Conservatively, we estimate 312 listed species, 106 candidate pronghorn, Chittenango ovate that nearly 40 of these species have species, and over 1,000 species of amber snail, and Wyoming reached such low population numbers concern. Of these, there are 102 toad. Other names describe the beauty of the species, that a single isolated event could cause endangered species, including 11 birds, such as slender chub, autumn their extinction. Because many of these four tree snails, and 87 plants, in such buttercup, and winged species survive in only a fragment of low numbers that could be rendered mapleleaf mussel. their former range, a single catastrophic extinct by a single isolated incident, event could cause their extinction. such as a fire or hurricane. The most Among the southeastern aquatic species serious threats to these species include that are critically endangered are the the continued influx of competitive and tan riffleshell (Epioblasma florentina predatory nonnative species, and the walkeri), with only one reproducing fragmentation and degradation of population in Indian Creek, Virginia; habitats. Efforts needed to save these the plicate rocksnail ( plicata), species include removing or controlling currently found only in the Locust Fork, destructive invasive species (for more

Rio Grande silvery minnow Alabama; and the boulder darter information, see the article on the USFWS photo (Etheostoma wapiti), found only in the Hawaii’s Plant Conservation Strategy in Elk River in Tennessee and Alabama. this issue). Emergency management Recovery actions needed to save these needed to protect Hawaii’s critically species include developing propagation endangered species will also benefit technology, restoring habitat, reintro­ other listed species and at least 30 ducing the species into restored habitat, candidate species.

1 (see http://www.actionbioscience.org/newfrontiers/eldredge2.html)

12 ENDANGERED SPECIES BULLETIN JULY/DECEMBER 2003 VOLUME XXVIII NO. 4 While the Southern Appalachians and menting the wild populations. The Washington. Its faces imminent extinc­ Hawaii host groupings of critically efforts the Service and our partners tion resulting from disturbances to its endangered species, there are many make during the next five years will be sagebrush habitat, disease, predation, other such species across the Nation. crucial for preventing this species’ and loss of genetic diversity. We need to Some examples follow: extinction. develop a program to breed the rabbits The Carson wandering skipper The Mississippi gopher frog (Rana in captivity for release into the wild. Its (Pseudocopaeodes eunus obscurus) is capito sevosa) was once found in survival will depend on working with a butterfly currently known from only suitable habitat within the Lower Coastal our partners and stakeholders to imple­ two populations, one in Washoe County, Plain from Florida to eastern Louisiana. ment conservation actions and to Nevada, and one in Lassen County, Today, however, the frog is known from integrate these actions with agricultural California. It needs grassland habitats on only one small pond in extreme south- practices. alkaline substrates to survive, and this central Mississippi. It spends most of the Attwater’s greater prairie-chicken habitat type has been reduced by year underground, often using the (Tympanuchus cupido attwateri) may activities associated with development, burrows of the threatened gopher be North America’s most endangered certain agricultural practices, collection, tortoise (Gopherus polyphemus). In bird. Since 1996, captive-bred birds have and nonnative plant invasions. This rare spring, the frogs travel overland to reach been released on the Attwater’s Prairie- butterfly is also threatened by unscrupu­ small ephemeral ponds, where they Chicken National Wildlife Refuge and the lous collectors. mate and lay eggs. Most of these Texas City Prairie Preserve. However, The pallid sturgeon ephemeral ponds have been lost to these sites can support only a small (Scaphirhynchus albus) is a fish that forestry practices, agriculture, and, in number of prairie-chickens. Saving this has survived for over 200 million years some cases, conversion to permanent species will require strong partnerships but it is now on the verge of extinction. ponds stocked with game fish. Sur­ with private landowners. Prescribed After the construction of dams on the rounding habitats with gopher tortoise burns, brush control, conversion of land Missouri River, the ecosystem inhabited burrows have likewise been lost to back to native grasses and forbs, and by pallid sturgeon was almost com­ development and land use changes. grazing regimes that will foster native pletely altered. There is limited evidence Preventing the extinction of this unique species are needed. that reproduction is still occurring in the frog will require the restoration of Halting the loss of these and other wild. Most of the pallid sturgeon in the ponds and surrounding habitats and species will require continued collabora­ wild are 40 to 50 years old. The window the reintroduction of frogs from the tion between the Service and our many of opportunity for obtaining reproduc­ surviving population. partners. By working together, we can tion from these individuals is close to the The emergency-listed Columbia conserve the remaining habitats and end. Retrofitting Missouri River fish Basin pygmy rabbit (Brachylagus restore others, while at the same time hatcheries to accommodate the needs of idahoensis) has fewer than 50 individu­ supporting sustainable development and this unusual species is critical to aug­ als in the wild, all in Douglas County, land use.

Above: pallid sturgeon USFWS photo

Left: Carson wandering skipper Photo © B. Moose Peterson/WRP

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