Desert Yellowhead (Yermo xanthocephalus) As its name suggests, the desert yellowhead is a plant that grows in an arid environment and produces heads of numerous yellow flowers. It is a member of the aster family (Asteraceae). This species is known from only a 5-acre (2-hectare) site in the Beaver Rim area of southern Fremont County, Wyoming, administered by the Bureau of Land Management. The desert yellowhead was not discovered until 1990, and surveys conducted over past the 8 years have not located any additional populations.
The area occupied by the desert yellowhead is potentially vulnerable to surface disturbances from such actions as oil and gas development, compaction by vehicles, and trampling by livestock. To ensure that this plant and its habitat are conserved, the FWS proposed on December 22 to list the desert yellowhead as a threatened species.
Nine Texas Invertebrates On December 30, the FWS proposed to list nine species of small, cave-dwelling invertebrates native to a few sites in Bexar County, Texas, as endangered. All nine species are adapted to an environment without light. Two of the species, Rhadine exilis and Rhadine infernalis (no common name), are essentially eyeless ground beetles. Another, the Helotes mold beetle (Batrisodes venyivi), is completely eyeless. The Robber Baron Cave harvestman (Texella cokendolpheri) is an eyeless form of "daddy-longlegs." The remaining five species--the Robber Baron Cave spider (Cicurina baronia), Madla's cave spider (Cicurina madla), Cicurina venii, vesper cave spider (Cicurina vespera), and Government Canyon cave spider (Neoleptoneta microps)--are eyeless, or essentially eyeless, spiders.
These creatures are known from karst features (limestone formations containing caves, sinks, and fissures) in north and northwest Bexar County. The health of karst environments depends in large part on the health of the surface environment within their recharge zone. Karst areas are known to have complex groundwater flow paths that are very sensitive to pollution. Contaminants that enter the aquifer can quickly degrade underground ecosystems.
Threats to the habitats of these species include both the direct and indirect effects of urbanization in this rapidly growing region. Caves and karst features are often filled in, and the aquatic cave environment can be degraded by septic effluents, sewer leaks, and pesticide runoff. Predation of the cave invertebrates by the non-native fire ant (Solenopsis invicta) is another serious threat. Some caves also have been vandalized or filled with trash.
Twenty-eight caves known to harbor one or more of the native invertebrates are on private lands, 21 are on Department of Defense lands, six are on State-owned land, and one is on a county right-of-way. The Defense Department is taking the conservation of occupied caves on its property into consideration, and some of the private landowners have already expressed a willingness to work with the FWS to develop land management practices that conserve karst habitats.
Santa Ana Sucker (Catostomus santaanae) Historically one of the most common fish in southern California, the Santa Ana sucker has a historic range that coincides with the Los Angeles metropolitan area. The Santa Ana sucker once occurred widely in the Los Angeles, San Gabriel, and Santa Ana River drainages of southern California. It is now restricted to the headwaters of the San Gabriel River system, the lower part of Big Tujunga Creek in the Los Angeles River basin, and a lowland stretch of the Santa Ana River in Los Angeles, Orange, Riverside, and San Bernardino counties. Because of the danger of continuing habitat loss, the FWS proposed on January 26 to list the Santa Ana sucker as threatened. A non-native population introduced into the Santa Clara River system in Ventura and Los Angeles counties is not included in the listing proposal.
The Santa Ana sucker, typical of the sucker family, has large, thick lips and a small mouth used to "vacuum" algae and invertebrates from stream beds. It is about 6 inches (15 centimeters) long and has a dark, blotchy back and silvery underside. The sucker inhabits small, shallow streams and appears to be most abundant where the water is cool, clean, and clear, although the species can tolerate seasonally turbid water.
The sucker's decline was related to environmental impacts from the region's intense urban development. Water diversions, channelization, and concrete lining of streams, as well as erosion, debris torrents, and pollution, have destroyed or degraded the fish's habitat. Dams also have isolated and fragmented the remaining sucker populations. Impoundments provide habitat for introduced non-native fishes that prey on suckers or compete with them for habitat, which biologists believe also contributed to the species' decline. Approximately 35 percent of the current range of the Santa Ana sucker is on Angeles National Forest lands, including a small portion within the San Gabriel Wilderness.
Critical Habitat The FWS published proposals on December 30 to designate critical habitat in southern Arizona for two listed species, the cactus ferruginous pygmy owl (Glaucidium brasilianum cactorum) and a plant, the Huachuca water umbel (Lilaeopsis schaffneriana ssp.recurva).
In southern Arizona, the pygmy owl nests within tree and cactus cavities. It is endangered by the loss or modification of habitat due to dams, water diversions, and urbanization. The proposed critical habitat for this species includes specific river flood plains and Sonoran desert scrub communities in Pima, Cochise, Pinal, and Maricopa counties. The Huachuca water umbel, a semi-aquatic plant, occurs in cienegas (desert marshes), springs, streams, and rivers. Threats to this species include competition with non-native species, droughts, destructive floods, and habitat degradation caused by livestock overgrazing, water diversions, dredging, groundwater pumping, and certain recreational activities. Proposed critical habitat for the water umbel includes specific stream courses and adjacent riparian areas in Santa Cruz and Cochise counties.
Critical habitat designations do not affect private activities unless there is some Federal involvement. Federal agencies, however, must ensure that any actions they authorize, fund, or carry out do not adversely modify designated critical habitats. The required maps and detailed descriptions of the proposed critical habitats for the pygmy owl and water umbel were published in the December 30 Federal Register. When these species were originally given ESA protection, the FWS decided that taking the additional step of designating critical habitats would not be prudent because publishing specific locations could attract plant collectors and lead to harassment of the owl. However, on November 25,1998, a district court judge ordered the FWS to issue proposed critical habitat designations with 30 days.
Final Listing Rules
Topeka Shiner (Notropis topeka) Historically, the Topeka shiner was a common fish in small prairie streams throughout Kansas, Iowa, Minnesota, Missouri, Nebraska, and South Dakota. Currently, however, it occurs in only about 20 percent of its former range due to widespread habitat modification and water quality degradation. Sedimentation, water diversions, and the loss of riparian buffers damaged the aquatic habitat, and dam construction fragmented some of the remaining populations, restricting genetic interchange. The Topeka shiner is now restricted primarily to a few tributaries within the Mississippi and Missouri river basins. The vulnerability of this small fish led the FWS to list the Topeka shiner on December 15 as endangered.
St. Andrew Beach Mouse (Peromyscus polionotus peninsularis) As their common name indicates, beach mice inhabit not houses and other structures but coastal sand dunes, where they excavate burrows and feed on plant seeds and insects. The St. Andrew beach mouse once lived along nearly 54 miles (87 km) of Florida's panhandle beaches from Gulf County to Crooked Island in Bay County. Over time, its habitat has been reduced by storms, non-storm related shoreline erosion, and coastal development. Other threats include predation by domestic cats and competition from house mice, both of which are associated with beachside development. An estimated 500 St. Andrew beach mice remain. On December 18, the FWS listed this subspecies as endangered.
Harbor Porpoise (Phocoena phocoena) In 1993, the National Marine Fisheries Service (NMFS), which has primary ESA jurisdiction over most marine species, proposed to list the Gulf of Maine/Bay of Fundy population of the harbor porpoise as threatened due to the rate of porpoise bycatch in the area's gillnet fishery. Since that time, however, NMFS has received information regarding the population's status and fishery management actions that reduce bycatch. Because NMFS has determined that ESA protection for the Gulf of Maine/Bay of Fundy population is not warranted, it published a withdrawal of the listing proposal in the January 5, 1999, Federal Register.