Biology In Your Backyard
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When thinking about plants and animals that inhabit hot arid lands of the southwestern United States, fish are easily overlooked by most people. However, these desert lands often contain isolated springs or cienegas (a Spanish term referring to permanently saturated "seep wetlands") and streams supporting native fishes that occur no where else in the world. (more...) In the semi-arid interior of western North America, riparian cottonwood, willow, and other native species are being replaced by exotic shrubs and trees such as saltcedar and Russian-olive, which now dominate many riparian systems throughout the western United States, including Nevada. These changes in riparian woody plant composition have been associated with loss of plant diversity, degradation of habitat, decreased channel conveyance, increased water loss, and loss of aesthetic and recreational opportunities. Investigators at the Fort Collins Science Center (CO) are examining how environmental factors influence the susceptibility of a river to invasion, especially by saltcedar and Russian-olive. Land managers need this information to identify which systems are most susceptible to invasion by exotics and which are most likely to respond positively to restoration efforts.  seGreater Sage-Grouse currently inhabit 56% of their historic range, leaving some populations isolated from each other. Questions remain about the genetic viability of and distinctions between different populations of this bird. Scientists from the Fort Collins Science Center (CO) are completing DNA analysis of Greater Sage-Grouse sampled across their entire range of 11 states (including Nevada) and two Canadian provinces. These data will provide information to help understand gene flow, genetic diversity, and evolutionary history between many populations of grouse and enable comparisons between all surveyed populations. With this information, managers can develop species-wide management strategies that take into account the entire "genetic landscape" of this species. The Department of the Interior needs information about the size of golden eagle (Aquila chrysaetos) population(s) in the western United States as a basis for evaluating the potential effects of harvest of golden eagles by Native Americans. (more...) Approximately 45 percent of the sagebrush region, or 45-68 million acres, is public land managed by the U.S. Bureau of Land Management and the U.S. Forest Service. Consequently, these agencies share the primary responsibility for managing land use and detecting habitat change, maintaining wildlife diversity and abundance, and restoring degraded habitats over a large portion of the Intermountain West. (more...) During the Comstock mining era of the late 1800s, liquid mercury was used to process gold and silver ore mined from Virginia City, Nevada and nearby areas. Along with the waste rock, known as tailings, 7,500 tons of mercury are believed to have been released into the Carson River watershed. (more...) Rapid population growth in the Western United States over the last century has placed increasing strains on our water supplies and aquatic ecosystems. (more...)  ishFish biologists at the Fort Collins Science Center (CO) are conducting studies on the Lower Colorado River documenting spawning requirements for native razorback suckers and bonytail, both of which are federally endangered, and evaluating the use of predator-free, off-channel rearing ponds for their young. Wild fish larvae are collected at spawning sites and relocated to these "refugia," where juvenile fish can grow to more than 30 cm (about 14 inches) in length. Then, when these larger fish are restocked to the main channel, losses to non-native fish predators are greatly reduced, and surviving fish will live to reproduce. In addition, biologists are working with U.S. Fish and Wildlife Service hatcheries to determine whether exercise and predator-exposure techniques will further improve the post-stocking survival of these fish. Studies and predation trials are being conducted at Achii Hanyo Fish Facility near Parker, Arizona. Riparian areas in the western United States, which comprise only 1% of the landscape but support a higher diversity of breeding songbirds than any other habitat, have been severely impacted by human activities, particularly livestock grazing. (more...). Expansion of exotic weeds such as cheatgrass (Bromus tectorum) is the major factor that contributes most to the decline of arid sagebrush communities in the Intermountain Region. Exotic annual grasses have become dominant and threaten much of the more arid portions of the sagebrush biome, with mean fire return intervals shifting from >50 years to <10 years. (more...)  chWild horse populations increase at a constant high rate on western rangelands, creating a management challenge for the Bureau of Land Management (BLM). What's more, they're hard to count, and accurate estimations of population size are critical in management decisions. Scientists from the Fort Collins Science Center (CO) are working with the BLM and state agencies to conduct the research needed to inform science-based management decisions. In wild horse management areas in Nevada, scientists are testing combinations of population estimation techniques to generate more accurate herd counts. |
U.S. Department of the Interior | U.S. Geological Survey
URL: http://biology.usgs.gov/wro/backyard/nv.html
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Page Last Modified:
Monday, 23-Oct-2006 14:51:11 MDT
