9 resultados para COLORADO SHORTGRASS STEPPE

em DigitalCommons@University of Nebraska - Lincoln


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One hundred forty-five cliff swallows, Petrochelidon pyrrhonota, were examined for cestodes in two separate surveys in Weld County, Colorado. Seven species representing four genera were found. Angularella audubonensis sp. n. is differentiated by the small size of the rostellar hooks (8.4-13.5 μm) and the medial relationship of the cirrus pouch to the osmoregulatory canals. Other species collected were Angularella beema, Anonchotaenia globata, Mayhewia ababili, Vitta magniuncinata, Vitta parvirostris and Vitta riparia. Seven new hosts and geographic distribution records were established for Colorado, and six new records were determined for North America.

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For hundreds of years black-tailed prairie dogs inhabited the Great Plains by the millions, improving the grazing for bison and pronghorn antelope, digging escape holes and homes for burrowing owls and rodents, and serving as prey for badgers, coyotes, hawks, and bobcats. This book by the renowned naturalist and writer Paul A. Johnsgard tells the complex biological and environmental story of the western Great Plains under the prairie dog’s reign—and then under a brief but devastating century of human dominion. An indispensable and highly readable introduction to the ecosystem of the shortgrass prairie, Prairie Dog Empire describes in clear and detailed terms the habitat and habits of black-tailed prairie dogs; their subsistence, seasonal behavior, and the makeup of their vast colonies; and the ways in which their “towns” transform the surrounding terrain—for better or worse. Johnsgard recounts how this terrain was in turn transformed over the past century by the destruction of prairie dogs and their grassland habitats, together with the removal of the bison and their replacement with domestic livestock. A disturbing look at profound ecological alterations in the environment, this book also offers a rare and invaluable close-up view of the rich history and threatened future of the creature once considered the “keystone” species of the western plains. Included are maps, drawings, and listings of more than two hundred natural grassland preserves where many of the region’s native plants and animals may still be seen and studied. This excerpt includes the Preface and Chapter 1, "The Western Shortgrass Prairie: A Brief History."

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In 1984 and 1985 seasonal changes in phytoplankton were studied in a system of three lakes in Loch Vale, Rocky Mountain National Park, Colorado. Three periods were evident: (1) A spring bloom, during snowmelt, of the planktonic diatom Asterionella Formosa, (2) a mid- summer period of minimal algal abundance, and (3) a fall bloom of the blue-green alga Oscillatoria limnetica. Seasonal phytoplankton dynamics in these lakes are controlled partially by the rapid flushing rate during snowmelt and the transport of phytoplankton from the highest lake to the lower lakes by the stream, Icy Brook. During snowmelt, the A. formosa population in the most downstream lake has a net rate of increase of 0.34 d-1, which is calculated from the flushing rate and from the A. formosa abundance in the inflow from the upstream lake and in the downstream lake. Measurement of photosynthetic rates at different depths during the three periods confirmed the rapid growth of A. formosa during the spring. The decline in A. formosa after snowmelt may be related to grazing by developing zooplankton populations. The possible importance of the seasonal variations in nitrate concentrations were evaluated in situ enrichment experiments. For A. formosa and O. limnetica populations, growth stimulation resulted from 8- or 16-micromolar amendments of calcium nitrate and sulfuric acid, but the reason for this stimulation could not be determined from these experiments.

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Irrigation is vital to the economic activity of the west-central Great Plains. The crops grown, the distribution of center-pivot irrigation systems, and the basic transportation infrastructure is the same in northwest Kansas, northeast Colorado, and southwest Nebraska. But buyers of agricultural land face a different price for irrigated cropland in each of the states, even when the production characteristics of the land are similar. After accounting for factors like productivity and local property tax differences, we argue that it is the difference in water marketing rights between the three states that explains the price difference. The link between land values and water marketing rights is statistically developed by using Ordinary Least Squared (OLS) regression techniques. After adjusting for differences in property taxes, the analysis reveals that the implicit value of full water-marketing rights in the region is approximately $1,026 per acre. This valuation is within the range of estimates provided by other comparable studies across the country.

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New and improved strategies are needed for managing overabundant blackbird (Icteridae spp.) populations in some areas of the United States. From 2004 to 2007, we evaluated sodium lauryl sulfate (SLS) as a wetting agent during controlled outdoor cage and flight pen tests in Colorado and small-scale field tests at urban blackbird roosts in Missouri. In the outdoor cage tests (ambient temperature -5 to 2° C), mortality of male red-winged blackbirds (Agelaius phoeniceus) sprayed with 1, 2, and 5 ml of SLS on the back feathers only, on the breast feathers only, or on both breast and back feathers ranged from 25% to 100%. A SLS spray on male red-winged blackbirds at 2° C ambient temperature with 1 ml of SLS sprayed on breast feathers and back feathers resulted in 90% mortality in less than 60 minutes. In a flight pen test (-12 to -5° C ambient temperature ), SLS sprayed at 20 l per 3,400 l of water with a single ground-based sprinkler-head system over 35 male red-winged blackbirds roosting in cedar trees (Juniperus virginiana) resulted in 53% mortality. There was no mortality in the control group exposed to the same treatment without the SLS. Small-scale field tests conducted in Missouri at 6 sites with a single ground-based sprinkler-head spray system and at 2 sites with 4 sprinkler-head spray systems resulted in mortality that ranged from 0 to 4,750 and 4,500 to 15,000 blackbirds and starlings, respectively. Spray operations lasted from 28 to 208 minutes. Each spray covered about 200 m2 . At all sites, mortality of blackbirds sprayed with the SLS occurred as soon as 30 minutes post-SLS application. Mortality at two sites where pump problems precluded completing the spray ranged from 0 to 800 birds. Air leaving the system as the system was activated caused birds to flush from the roost trees. Poor water quality and pump durability were problems at some sites.

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Chelydra serpentine serpentine (Common Snapping Turtle). Nesting Behavior and Site Selection. On May 31, 2008, we observed a ca. 36 cm CL Chelydra serpentine serpentine in unexpected nesting circumstances. Observations were made from 0908 to 1027 h on clear day with ambient temp ca 24° C. The nest site near Longmont, Colorado, USA (40.1599528°N, 105.1259861°W; WGS84) was 4.3 m from a seasonal ditch running north-south to connect two lakes, one on either side of a busy road. The intriguing aspect of the nest location was that it was immediately adjacent to a heavily traveled concrete sidewalk that bordered a road with a high volume of traffic. The frequent foot traffic on the sidewalk and virtually constant vehicle traffic on the adjacent road did not deter the turtle from the particular nest location, even though virtually identical soils, gradients, and directional aspects were available equidistant from the ditch, but away from constant human activity.

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Rhodamine B is a dye that when ingested results in fluorescent bands in growing hair and whiskers of many mammals. Previous research at Wildlife Services’ (WS) National Wildlife Research Center (NWRC) found that rhodamine B is a successful biomarker in raccoon whiskers and that raccoons do not have a taste aversion to the dye when it comprises ≤ 3% of a bait. Our study assessed the ease of bait distribution, whisker collection, and evaluation of the biomarker for potential use in the Oral Rabies Vaccination (ORV) program administered by the WS National Rabies Management Program (NRMP). In collaboration with WS operations personnel from Ohio and Michigan, 750 fishmeal polymer baits each containing 150 mg of rhodamine B were hand distributed at NASA’s Plum Brook Station, Sandusky, Ohio in the summer of 2008. Four weeks after baits were distributed whiskers from 162 raccoons were collected. Wildlife Services biologists and technicians evaluated the whiskers for fluorescence using a handheld UV magnifying lamp. Biologists then sent the whiskers to the NWRC, Ft. Collins, Colorado for confirmation of fluorescence under a UV microscope. Results suggest a high level of agreement between the two methods of evaluation. Surveys completed by biologists confirmed that the ease of use, less invasive sampling techniques and promptness of results obtained through the use of rhodamine B are advantageous to the tetracycline biomarker presently used by the ORV program. All participants recommended further evaluation of rhodamine B for its inclusion in future efforts requiring biomarker evaluation.

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The Wildlife Master (WM) Program in Colorado was modeled after the highly successful Master Gardener volunteer program. In 10 highly populated suburban counties with large rural areas surrounding the Denver Metro Area, Colorado State University (CSU) Cooperative Extension Natural Resources agents train, supervise and manage these volunteers in the identification, referral, and resolution of wildlife damage issues. High quality, research-based training is provided by university faculty and other professionals in public health, animal damage control, wildlife management and animal behavior. Inquiries are responded to mainly via telephone. Calls by concerned residents are forwarded to WMs who provide general information about human-wildlife conflicts and possible ways to resolve complaints. Each volunteer serves a minimum of 14 days on phone duty annually, calling in from a remote location to a voice mail system from which phone messages can be conveniently retrieved. Response time per call is generally less than 24 hours. During 2004, more than 2,000 phone calls, e-mail messages and walk-in requests for assistance were fielded by 100 cooperative extension WMs. Calls fielded by volunteers in one county increased five-fold during the past five years, from 100 calls to over 500 calls annually. Valued at the rate of approximately $18.00 per volunteer hour, the leveraged value of each WM was about $450 in 2005, based on 25 hours of service and training. The estimated value of the program to Colorado in 2004 was over $45,000 of in-kind service, or about one full-time equivalent faculty member. This paper describes components of Colorado’s WM Program, with guides to the set-up of similar programs in other states.

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Abstract The goal of this study was to conduct a comparative analysis of three university recycling programs. This study looked at several aspects of the programs that included the diversion rates, per capita ratios of materials recycled and disposed, and the average net costs of waste disposal and waste diversion. The universities included in this study were the University of Nebraska-Lincoln, the University of Colorado at Boulder, and the University of Oregon. To gather the information necessary for this analysis, I contacted each of the university’s recycling coordinators. To determine the average net costs of waste disposal and waste diversion I requested both the recycling budget and solid waste budget from each university for the fiscal years of interest which included: 2006-2007, 2007-2008, and 2008-2009. To calculate the diversion rates and per capita ratios, I requested performance records from each university listing the tonnage of materials recycled and disposed for the same years. This study’s findings reported that the average net costs for waste diversion in all three universities were $22-$122 less per ton than costs for waste collection and disposal. This study also indicated that the universities with the highest diversion and recycling rates were the University of Colorado at Boulder and the University of Oregon. The university with the lowest waste generated per capita was the University of Oregon followed by the University of Nebraska-Lincoln.