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Endangered, Threatened, and Sensitive Fauna and Flora
The loss of plants and animals changes ecosystem functions in ways difficult to predict or observe, until serious impacts arise. Once species have been eliminated from the state or even a portion of the state, restoring the lost species and ecological functions may be difficult, if not impossible. An example is the removal of perennial grasses and forbs from large portions of Nevada'ssagebrush and sagebrush steppe vegetation zones. As shrubs and cheatgrass filled
the voids, the stage was set for large, intense wildfires and the accelerated invasion of non-native annual weeds and grasses. Actions that subtract species from the total mix of native plant and animal communities are not small matters.
The use and development of Nevada's natural resources unfortunately has resulted in losses of native fishes, mammals, and birds. Many animal species have become extinct or have been extirpated (i.e., no longer inhabit Nevada, but still occur elsewhere) (Figure 3-3). A total of 26 taxa no longer exist in Nevada. Sixteen are extinct and ten are extirpated. A majority of the extinct species lived in aquatic environments, including springsnails, fishes, and one amphibian. These losses highlight the sensitivity of these ecosystems to dewatering, as well as the alteration of stream channels and riparian vegetation.
As the growing population and economy increases demands placed on Nevada's limited water resources, there is a corresponding need for innovative water management solutions to sustain aquatic habitats and species from additional losses. Currently, records do not indicate that any plant species has been completely extinguished from the state. However, many plant species are declining and no longer occupy much of their former range.
Forty plant and animal species or subspecies are on the federal List of Endangered and Threatened Wildlife and Plant Species. Overall, 644 taxa are considered rare or sensitive in Nevada (Table 3-8).
The loss and fragmentation of native habitats and competition by nonnative species are the biggest threats to biodiversity. Activities associated with habitat loss and deterioration include urban sprawl; surface water diversions; overgrazing by domestic and wild animals; mineral development and exploration; and concentrated outdoor recreation, especially involving careless off high vehicle use. Wildfires and non-native plant invasions have destroyed millions of native habitat acres in recent years. Proactive habitat conservation has become vitally important.
The regulatory approach to conserving Nevada's most imperiled plants and animals is based on federal or state programs that designate, study, and plan for the protection and recovery of threatened and endangered species and their habitats. The U.S. Fish and Wildlife Service (FWS) administers the federal Endangered Species Act of 1973 (ESA), as amended. As the lead agency for ESA implementation, the FWS has responsibility for ensuring that threatened and endangered species will be sufficiently protected and can survive in their natural habitat.
Public or private land use activities that may jeopardize listed species must be permitted and a plan approved to avoid, minimize, or mitigate the taking of individuals of endangered or threatened species. Endangered means a species of plant or animal is in danger of being eliminated throughout all or a portion of its range. Threatened means a species is likely to become endangered in the foreseeable future. The FWS has designated, or "listed", 24 distinct Nevada taxa as endangered and 16 as threatened (Table 3-8). In addition, the BLM and the USFS manages 234 sensitive and rare taxa.
Of the 40 species federally listed as endangered or threatened, 37 are protected under state statutes and regulations administered by NDOW and NDF. Under state law, a species may be designated as protected, threatened, endangered, or sensitive. Capturing, removing or destroying plants and animals on the state's fully protected list is prohibited unless a special permit has been obtained from the state Divisions of Forestry and Wildlife. Of the 86 wildlife species protected under Nevada Administrative Code 503.050, most are fishes (45) and birds (30) (Figure 3-4, Table 3-7).
The NDF administers a regulatory program (NRS 527.270, NAC 527.010) that requires a permit to be obtained prior to removal or destruction of any of the 23 "critically listed" native flora species or its habitat. Adoption of new
regulations during 2000 for the native flora program provides for establishment of special management areas for critically endangered plants. Specific management area plans are required so that native flora can be protected while land and resource uses can continue.
An example is the Steamboat buckwheat (Eriogonum ovalifolium var. williamsiae), which occupies a single site in the Steamboat Springs geothermal area of Washoe County. An established management area and plan provides for the coexistence of an operating geothermal power plant and the habitat conditions necessary for plant population survival. Plants may be removed from the state protected list. In 2001, the NDF and NNHP de-listed two plants, Beatley milkvetch (Astragalus beatleyae) and Ruby Mountain primrose (Primula capillaries). These endemic species are no longer considered at high risk because land use and management changes have alleviated threats.
Cactus and yucca species found in the Mojave Desert ecoregion are in high demand for landscaping. To ensure that the number of cactus and yucca plants removed does not put the species at risk, permits must be obtained from NDF to harvest cactus and yucca species, such as Joshua trees, on private lands destined for development. Though the number of harvest permits issued remains relatively constant, the quantity of tags given for individual plants has increased over 60 percent since 1990 (Table 3-9.). Surveys have not yet been conducted to determine the appropriate population level of these species.
Thousands of cactus plants are taken illegally from public lands. On BLM managed land, all collectors are required to obtain a permit prior to harvesting cactus or yucca. The BLM only permits harvesting on land that will be permanently disturbed. Owners of projects on BLM land must salvage the plants, which are used by the BLM for site restoration, often in desert tortoise habitat. The cactus theft problem is serious enough for the National Park Service to implant computer-tracking chips into larger barrel cactus where poaching is high on the Lake Mead National Recreation Area. The BLM also has identified poaching hot spots. One is near Searchlight where hundreds of exposed 'cactus butts' have been found. BLM intends to install and maintain education signs in these areas.
Rare and Sensitive Species
As part of the state's early warning system for the conservation of biodiversity, the Nevada Natural Heritage Program (NNHP) tracks more than 600 rare and sensitive taxa (i.e., species and subspecies). This is accomplished through well-established biological inventory methods and data sharing with the member agencies of the Nevada Biodiversity Initiative and other collaborators. Nationally, the state Natural Heritage Program network is recognized as the leading source for detailed information on rare and sensitive plants and animals, and on identification of biodiversity "hotspots."
The Heritage method, which is used nationwide, is followed to evaluate the relative risk of extinction using data on the number and condition of populations and individuals; the area or range occupied by the species; population trends; known threats; and protection or management status. Biologists evaluate each species against these risk factors based on the best available scientific information and assign the appropriate "rank". Ranks are classified globally and within individual states as secure, apparently secure, vulnerable, imperiled, critically imperiled, possibly extinct, and presumed extinct. Extensive files are maintained on the biology and mapped locations for each sensitive species.
Using the Heritage method of assessing biodiversity significance, the NNHP identifies 493 sensitive species (Figure 3-5). Taxa classified as sensitive include those with federal or other Nevada agency status, and those ranked as vulnerable or of greater risk, or experiencing downward trends indicating some level of range-wide imperilment. In general, a sensitive species is any taxon whose long-term viability has been identified as a concern. Sensitive species are widely distributed throughout the state (Figure 3-6). A separate Watch List includes taxa that could qualify for the sensitive list in the future, or that recently have been removed from the sensitive list. NNHP passively accumulates data for watch list taxa. The watch list consists of 151 taxa (Figure 3-5).
A state-by-state assessment recently published by NatureServe, the parent organization of the Natural Heritage Network, provides a relative ranking of states using measures of biological conditions - diversity, risk, endemism, and extinctions (NatureServe, 2002). Of the 50 states, Nevada ranked 11th in species diversity; 3rd in rarity and risk level; 6th in endemism (taxa unique to Nevada); and, 11th in extinctions. The 3rd rank in the rarity and risk measure can be attributed to the relatively large percentage of native fishes, amphibians, plants, and birds that are considered to be vulnerable, imperiled, or critically imperiled.
The NNHP, working with biologists and resource managers from many organizations, identifies landscape units that contain assemblages of sensitive species. The Natural Heritage Scorecard reports on particular conservation sites defined by occurrences of sensitive species that are appropriately managed as a unit based on common biological, land-ownership, and conservation-planning criteria. Sites with high diversity, protection urgency, and adaptive management requirements become the highest priority conservation sites. Scorecard 2000 brings attention to a total of 66 sites (Figure 3-7).
Many of the Scorecard sites are associated with unique water and spring systems and sand dunes in rural areas. Others are near rapidly growing urban areas (Nevada Natural Heritage Program, 2000). The Scorecard, sensitive and rare species rankings and reports, and other biological resource assessments are performed by NNHP and made readily available. This information, when used in community master planning, land development project design, or public resource management can avert habitat loss or population declines in vulnerable species that trigger stringent federal or state regulations.
Coordinated planning and cooperative management to conserve special status species is growing. In southern Nevada, state, local and federal partners have prepared and are implementing the Clark County Multi-Species Habitat Conservation Plan. This far-reaching plan covers 78 different taxa and identifies the needed management and monitoring actions for a variety of habitats including low elevation uplands, desert riparian habitats, low elevation springs, and low elevation plant species.
To avoid further declines in Greater Sage Grouse populations in the northern half of the state, the Governor established a special task force office to prepare a state strategy. Sage Grouse populations have declined in different portions of its western U.S. wide range by 40 to 80 percent since the 1950's. The strategy emphasizes local collaborative conservation planning. The intention of enabling development of area-specific plans is to harmonize customary resource uses and locally meaningful incentives with actions to maintain good habitat conditions, improve degraded habitat, and stabilize, then increase, the bird's population.
Another instance of model collaborative conservation planning is development of the Nevada Bird Conservation Plan by the Nevada Partners in Flight (NPIF) (260 Page Adobe PDF File). Seeing indications of continent-wide and local declines in the population, distribution, and habitat of migratory and resident songbird and other species, the National Fish and Wildlife Foundation brought together federal, state, and local government agencies, foundations, conservation groups, industry and the academic community to form a program to address the problem. By 1993, interested parties coalesced into the Nevada Working Group of Partners in Flight.
During the next several years, ornithologists, wildlife experts, and bird watchers networked in the joint goal of developing a comprehensive bird conservation plan intended "to keep common birds common." A priority list of 46 species was developed for 15 major habitat types. Although long-term population data specific to Nevada were lacking for most of the priority species, population objectives were set for all species and then nested within one or more major habitat types. Strategies outlined how the objective could be achieved. The strategies usually address habitat management activities, but monitoring strategies and public awareness strategies also were deemed necessary. In all, 63 bird conservation objectives were set. The plan creates a modern day baseline for species monitoring and specific long-term goals.
For example, the Northern Goshawk and White-faced Ibis objectives are to maintain at least 300 and 4000 nesting pairs, respectively, in Nevada during the next three years. The White-faced Ibis is a priority species that occupies wetlands and lake habitats, nesting in colonies on sites with prolonged flooding to discourage predators and to prevent damage to their nests. Drought, water diversions, and thin eggshells from pesticides contributed to this bird becoming a species of concern. The Northern Goshawk inhabits aspen groves and coniferous forest, habitat types that are decreasing. Ultimately, the Nevada Bird Conservation Plan sets the stage for better stewardship and greater public awareness of the extraordinary bird life found in the state. Currently, NPIF is implementing a statewide all-bird monitoring program, which is being coordinated by the Great Basin Bird Observatory (GBBO).
In addition to the work being done by NPIF and the GBBO, Nevada has initiated an Important Bird Areas (IBA) Program. Through this program, locations with significant diversity of birds or large concentrations of single species are designated as an Important Bird Area. The Nevada IBA program is part of an international program. The over-arching goal of the Nevada IBA Program is to raise awareness of and promote enhanced management of IBA sites. The program will contribute to the preservation, maintenance, and recovery of bird populations in Nevada in collaboration with private landowners, federal and state agencies, and NGO's responsible for the well being of birds, wildlife and their habitats. The program started in Spring 2001, already has received recommended nominations for more than 50 sites.
Many people with different interests are striving to be better stewards of Nevada's living resources. The key to effective ecosystem management and sustaining biodiversity in concert with population and economic growth is collecting, sharing, and distributing information on the status of flora and fauna. Each year more is learned about the plants and animals that live here and about the ecology of native plant and animal communities. However, rapid population growth and changes in land use often outpace the ability of agencies to collect and analyze detailed data needed on the distribution and abundance of sensitive, as well as a wide range of other plants and animals.
More base-line data on common species would help ensure that management efforts are properly directed to truly vulnerable species. Also, coordination among environmental scientists and managers in different disciplines is needed to integrate data on the physical and biological components of ecosystems, to better understand the conditions which contribute to declining populations. More scientific information on causes for species imperilment will lead to greater certainty in conservation strategies. Increasing collaborative projects among government, industry, and conservationists is already bringing Nevadans closer to the goal of sustaining biodiversity while meeting the resource needs of urban and rural communities.
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