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Birds
Nevada is home to a large and diverse group of resident and migratory bird species, and yet since birds are mobile, none of the 283 native species are considered endemic. The popularity of bird watching has grown steadily. Premier bird viewing areas can be found throughout the state, including urban areas such as Oxbow Nature Center in the heart of Reno and the Henderson Bird Preserve in the Las Vegas metropolitan area. Large wetland complexes in northwestern and northeastern Nevada attract large populations of many migratory shorebird, waterfowl, and wading bird species. The Bird Conservation Plan (1999) [260 page Adobe PDF File], prepared by Nevada Partners in Flight, provides comprehensive information about nongame birds that are of special conservation concern (Table 3-5).
State wildlife regulations classify birds as upland game, migratory game, protected, or unprotected. Continental and local declines in numerous bird populations have led to concern for the future of migratory and resident bird species, regardless of game of nongame designation. The reasons for declines are complex, largely the result of habitat elimination, conversion, and fragmentation, including critical wintering and migratory habitat. With data on nongame birds sorely lacking, scientists, government agencies and the concerned public have become engaged in conservation initiative focusing on nongame landbirds, waterfowl, and shorebirds. Collaborative conservation and data collection efforts include the Nevada Working Group of Partners in Flight, the Great Basin Bird Observatory, and the Intermountain West Joint Venture component of the North American Waterfowl Management Plan (Nevada Partners in Flight, 1999).
Fifty game bird species may be found in the state, many of which are introduced. Sixteen birds are classified as upland birds, of which eight are native to Nevada and eight are introduced. The native game birds are Sage Grouse, Blue Grouse, Sharptail grouse, Mountain Quail, and Gamble's Quail.
Greater Sage Grouse numbers and distribution have declined throughout Nevada and the western U.S. As with other species in decline, a major factor is habitat loss or alteration - the cumulative effects of land and water development that, in this case, converted and fragmented the Great Basin sagebrush and sagebrush steppe ecosystems. Historic grazing, cheat grass, and wildfires are among the negative impacts. Nevada Sage Grouse have a stronger reliance on wetlands and riparian areas for their survival, due to the short precipitation season. Since 1970, Greater Sage Grouse numbers have decreased between 49 and 60 percent. Meanwhile hunting harvest declined by 72 percent.
A statewide strategy was adopted in 2001 to establish regional cooperative working groups that will design and implement scientifically sound management plans to ensure that the Greater Sage Grouse and healthy habitat areas does not continue to decline (Nevada Division of Wildlife, 2001).
Several species have been introduced in natural and altered habitats (e.g., farmland) to provide more hunting opportunities. Chukar, originally from India and Pakistan, have adapted to the drier, rockier terrain of northern Nevada and are the most common upland game bird found in the state today. Hungarian partridge have been introduced into areas with similar habitats.
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| The Sage Thrasher requires dense stands of tall sagebrush. Breeding adults conceal nests in or underneath a shrub. An important characteristic for nest placement is consistent foliage density, which protects the young from temperature extremes and predators. Sage Grouse prefer low sagebrush expanses during portions of their life cycle. Sage Grouse and Sage Thrashers are examples of "sagebrush obligate" species with differing sagebrush habitat requirements. These differences exemplify one of the challenges in managing diversity within sagebrush ecosystems. Photo by Paul Slichter. |
The efforts of sportsmen's groups and the NDOW to build water collection devices in dry habitat have substantially increased the range and population levels of Chukar. A similar effort in southern Nevada has greatly expanded the range of Gamble's quail. Over 1,000 guzzlers have been constructed to provide water for wildlife in areas where natural supplies are limited or nonexistent.
Himalayan Snowcock occupy a narrow habitat range above tree line in the Ruby and East Humboldt mountain ranges of Elko County. Ring-necked and White-winged Pheasants are imports from Asia and small numbers now inhabit agricultural valleys in northern Nevada. Wild Turkeys from Texas and California also have become established in several agricultural areas. California and Scaled Quail are also successful transplants to Nevada.
Upland game bird population levels are highly influenced by climatic conditions. The NDOW uses annual hunting data to monitor population trends (Table 3-6). Biologists typically require more information than quotas and harvest data to evaluate the robustness or vulnerability of populations. Biological factors to consider include the quality and distribution of habitat conditions and the population size and trend of the species and its predators. Hunting factors could include weather and climate, hunting pressure, skill, and chance.
Migratory game birds include species found in the Families Anatidae (wild ducks, geese, brants, and swans), Columbidae (wild doves and pigeons), Gruidae (little brown cranes), Rallidae (rails, coots, and gallinules), and Scolopacidae
(woodcocks and snipes). These species depend on aquatic habitats and/or wetlands. Large numbers of each are found in the state during certain seasons as exemplified by estimated peak waterfowl populations shown in Table 3-7. Each year is different. Seasonal site-specific environmental conditions influence the abundance and distribution of different birds. Winter precipitation is an important short-term key to wetland habitat availability and maintenance. Significant wetland losses in the state have had an affect on water dependent bird populations, as well as other resident and migratory birds. For example, Mourning Dove and White-winged Dove populations fluctuate in response to moisture dependent habitat conditions. Dove populations have shown a long-term downward trend, possibly due to changes in agricultural practices and drought years
Approximately 235 non-game bird species occur in Nevada for all or part of their life cycle. This does not include the "accidental" occurrence of migrants that find their way here due to weather events or other misguidance. (In 2001, a Sabine's Gull, an arctic open-ocean bird, was observed in northwestern Nevada.) Historical information on the populations and trends of most nongame birds is quite limited. Birds occur in all habitats and life zones with the largest number of species utilizing water-associated habitats.
Twenty-five species of raptors are represented in Nevada, and a major raptor migratory corridor passes through the state. Favorable wind patterns tend to funnel major migrations of raptors through concentrated areas, making Nevada one of the premier spots to watch and monitor migrating raptors. Spring and fall migrating raptors are regularly monitored at Goshute Peak in eastern Nevada. Raptor populations are useful to wildlife researchers because they provide clues about the health of the environment. Raptors are also popular with wildlife watching and photography enthusiasts.
Passerines (i.e., perching songbirds) such as warblers, sparrows, finches, and flycatchers comprise 60 percent of the non-game species. Water and shorebirds, cranes, woodpeckers, hummingbirds, swifts, and kingfishers are among the other groups represented in our state. All wild birds, with the exception of the starling and house sparrow, are covered by the Federal Migratory Bird Treaty Act, and are further protected from shooting or capture by State wildlife regulations.
Amphibians and Reptiles
Sixteen native amphibians occur in the state. Amphibians generally require access to water and/or moist habitat conditions throughout their life cycle, and therefore are limited in number and distribution in Nevada. The Vegas Valley leopard frog (Rana fisheri), one of six native frogs, has gone extinct. The bullfrog (Rana catesbeiana) is one of two introduced amphibian species. It has become a dominant species in marsh and pond habitats, and preys on the young of native amphibian, fish, and reptiles. The bullfrog is the only amphibian game species. Two other native frog species, the relict leopard frog (Rana onca), and the Columbia spotted frog (Rana luteinventris) are classified as protected by state law.
The Amargosa toad (Bufo nelsoni) is one of nine native toad species. It is the only one classified as state protected. The toad is endemic to a small area in the Oasis Valley in the midst of the Amargosa Desert (southern Nye County).
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| The relict leopard frog, similar to the Amargosa toad, inhabits wetland patches in the Mojave Desert that contracted as the climate warmed and dried during recent millennia. More currently, water diversions and dams have impaired remaining habitat patches. Early records indicated the relict leopard frog lived in 64 locations. The species was thought to be extinct for 40 years until the 1990's, when eight populations were found. Two have been lost since then. Surviving populations are located at springs on the Lake Mead National Recreation Area. Agencies, such as NNHP, provide current information on the status, biology, and threats to sensitive species populations, an important step in conserving the state's biodiversity and avoiding strict regulations. Photo by Ross Hayley, NPS. |
While springs and ponds are essential habitat for young toads, adults can
tolerate drier habitat patches. Adults find shelter under bushes, woody structures, rocks, and rodent burrows. In the past, the limited habitat for this species was subjected to a variety of land disturbances that threatened its existence. A cooperative planning process involving federal and state agencies, Nye County, The Nature Conservancy (TNC), ranch owners and others produced a species conservation agreement. The Agreement sets specific conservation actions for the long-term survival of the toad. TNC also acquired a Wetland Reserve Program easement from a ranch owner, in concert with the Nevada NRCS. Other native toads occupy a variety of habitats, some relatively common and widely distributed, and others rare with narrow ranges.
The state's desert habitats are well suited to the 54 native reptile species. Thirty-six species are allowed to be collected commercially with a permit from NDOW. Commercial collectors provide reports on the number of reptiles collected. In the period 1992-1997, 138,871 individuals were collected; an amount 10 times greater than the quantity taken between 1986-1991 (10,679 individuals). Ninety percent of the collected reptiles consisted of four species that occur in northwestern Nevada. Baseline population and distribution data are lacking for most reptile species, so the long term effects of commercial collecting and unlimited reptile harvesting are unclear.
Two fully protected reptiles are the desert tortoise (Gopherus agassizii) and the banded Gila monster (Heloderma suspectum cinctum). The desert tortoise is the state reptile. It is federally listed as a threatened species. Special adaptations have enabled the tortoise to live in the extreme heat and dryness of the Mojave Desert ecoregion, such as being diurnal (i.e., an early bird and night owl), a thick shell to conserve water, and the ability to excavate their own burrow in order to beat the heat of the day. The Clark County Multi-species Habitat Conservation Plan is intended to protect desert tortoise and other special status species of the Mojave Desert at risk from rapid development, off-highway vehicle use, and other urban related threats.
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