DOI: 10.6073/pasta/903b03f348906d325aa045d4a89b5fba
title: SGS-LTER Long-term Monitoring Project: Spotlight Rabbit Count on the Central Plains Experimental Range, Nunn, Colorado, USA 1994-2006, ARS Study Number 98 (Reformatted to a Darwin Core Archive)

description: This data package is formatted as a Darwin Core Archive (DwC-A, event core). For more information on Darwin Core see https://www.tdwg.org/standards/dwc/. This Level 2 data package was derived from the Level 1 data package found here: https://pasta.lternet.edu/package/metadata/eml/edi/327/2, which was derived from the Level 0 data package found here: https://pasta.lternet.edu/package/metadata/eml/knb-lter-sgs/136/17. The abstract below was extracted from the Level 0 data package and is included for context: This data package was produced by researchers working on the Shortgrass Steppe Long Term Ecological Research (SGS-LTER) Project, administered at Colorado State University. Long-term datasets and background information (proposals, reports, photographs, etc.) on the SGS-LTER project are contained in a comprehensive project collection within the Digital Collections of Colorado (http://digitool.library.colostate.edu/R/?func=collections&collection_id=3429). The data table and associated metadata document, which is generated in Ecological Metadata Language, may be available through other repositories serving the ecological research community and represent components of the larger SGS-LTER project collection. Additional information and referenced materials can be found: http://hdl.handle.net/10217/83448. Rabbits are the most important small-mammal herbivores in shortgrass steppe, and may significant influence the physiognomy and population dynamics of herbaceous plants and woody shrubs. Rabbits also are the most important prey of mammalian carnivores such as coyotes and large raptors such as golden eagles and great horned owls. Two hares (Lepus californicus, L. townsendii) and one cottontail rabbit (Sylvilagus audubonii) occur in shortgrass steppe. In 1994, we initiated long-term studies to track changes in relative abundance of rabbits on the Central Plains Experimental Range (CPER). On four nights each year (one night each season, usually on new moon nights in January, April, July, October), we drove a 32-km route consisting of pasture two-track and gravel roads on the CPER. This was the same route as that driven for carnivore scat counts. Surveys began at twilight. Observers with two spotlights sat in the back of a 4WD pick-up driven at &lt;15 mph. We recorded the perpendicular distance (in m) to each rabbit using a meter tape or range finder; the direction of the rabbit relative to the road; and noted if individuals were solitary or in clusters. We also recorded any carnivores or other animals seen during spotlight surveys. Beginning in Spring 1998, we recorded the vegetation type (habitat) and topographic position of each rabbit seen, as well as position relative to human features, eg windmills, cattle guards, on the landscape. We used the number of rabbits of each species spotted per km of route as an index of relative abundance. We used line-transect approaches in DISTANCE to estimate population densities from perpendicular distance data. The Shortgrass Steppe Long Term Ecological Research (SGS-LTER) project was funded by National Science Foundation as one of the first sites in the US LTER Network in 1982. This collaborative, interdisciplinary research project was established in the Natural Resource Ecology Lab at Colorado State University by ecosystem scientists who learned novel approaches to study grassland ecosystems during the International Biome Program (IBP) (1968-1974). The SGS-LTER project was built upon the foundation of data and information obtained during IBP, as scientists sought to identify and follow, and often manipulate in experiments, important ecosystem processes over the long-term. The objectives of the SGS-LTER project were to investigate what mechanisms regulate processes in the shortgrass steppe. Research questions focused on how biotic and abiotic components of the ecosystem are coupled, where and when ecosystem components are most vulnerable to perturbations, disseminating information that would be helpful for rangeland management and assessing impacts of climate change. Scientists explored variations in the structure and function of the ecosystem over space and time and sought to understand how these aspects are governed by climate, natural disturbance, biota, physiography, and human use. Scientists at the SGS-LTER integrated long-term monitoring data, designed experimental studies, performed and advanced modeling techniques, and synthesized data to conduct innovative research, education, and outreach. The core SGS-LTER research site was established on the Central Plains Experimental Range (CPER) in Nunn, Colorado, part of the United States Department of Agriculture’s Agricultural Research Service. The research site sits in the rain shadow of the Rocky Mountains at the western edge of the shortgrass steppe of North America. The shortgrass steppe ecosystem evolved with grazing by the American bison, which has now been replaced by cattle. Grazing by domestic livestock is the primary land use of native grassland, which occupies about 60% of the land area of the shortgrass steppe. Short grasses dominate the vegetation community, which have adapted to grazing and less than 400 mm of annual rainfall. The topography is characterized by gently rolling hills, broad ephemeral stream courses and low flat-topped terraces. Aspects of physiography regulate the shortgrass steppe ecosystem, including landscape position, soil age, water holding capacity, soil depth and surface texture which, in turn, determine such properties as soil moisture storage, net primary productivity and the distribution of small mammals such as prairie dogs and pocket gophers. SGS-LTER scientists have expanded their research studies beyond the CPER to identify similar or different patterns in ecosystem structure and function in North American grasslands; across the Great Plains region and along the latitudinal gradient from Wyoming to Mexico. They also conducted cross-site collaborative research and compared their results and tested theories in grasslands located in South America, Asia and Africa. Funding from NSF for the SGS-LTER project ends in 2014, but over thirty years of research has resulted in a scientific team with diverse expertise, which produced over 1200 journal publications, almost 400 book chapters and over 200 theses. Data, products and other information produced from the SGS-LTER are available through the LTER Network Information System, Digital Collections of Colorado at CSU or upon request through ecodata_nrel@colostate.edu.