They're abundant in this area, but hard to count reliably. We outline a procedure for estimating the population sizes so that we can determine whether they're increasing or dwindling. We must both listen for their calls and visually confirm them.
Previous analysis showed this area to have reduced macroinvertebrate biodiversity, an important measure of ecosystem health. New observations indicate that conditions have improved; report includes methods and results of sampling.
A web-enabled database that provides for the capture, curation, integration, and delivery of bioassessment data collected by USGS, principally macroinvertebrate, algae, fish, and supporting habitat data from rivers and streams.
Manual for research program on the nesting habits of sea turtles of the Virgin Islands, with descriptions of species, nesting behavior, observation methods, record keeping, tagging, and tissue sample collection. (PDF file, 121 pp.)
Population size, foaling, deaths, age structure, sex ratio, age-specific survival rates, and more over a 14 year time span. This information will help land and wildlife managers find the best maintenance and conservation strategies.
Sixty-five sampling sites, selected by a statistical design to represent lengths of perennial streams in North Dakota, were chosen to be sampled for water chemistry and mercury in fish tissue to establish unbiased baseline data.
Sixty-five sampling sites, selected by a statistical design to represent lengths of perennial streams in North Dakota, were chosen to be sampled for fish and aquatic insects (macroinvertebrates) to establish unbiased baseline data.
Explains how we assessed the quality of a wetland as indicated by its plant species composition and abundance for marsh and swamp sites, to summarize the effectiveness of restoration projects in Louisiana.
Macroinvertebrate data collected by USGS or USFS from 73 sites from 2000 to 2007 and algal data collected from up to 26 sites between 2000 and 2001 in the Eagle River watershed, with emphasis on methods of sample collection and data processing.
North American Breeding Bird Survey (BBS) is a cooperative program that monitors the status and trends of North American bird populations. Includes files of results, analyses, route collection maps and raw data.
One of the greatest challenges for conserving grassland, prairie scrub, and shrub-steppe ecosystems is maintaining prairie dog populations across the landscape. Of the four species of prairie dogs found in the United States, the Utah prairie dog (Cynomys
Here we study effects of climate and groundwater on surface-water levels, the hydrological effects on wetland water chemistry, and the combined effects of climate, hydrology, and water chemistry on plant and animal communities of prairie pothole wetlands.
Complex interactions among hydrologic events initiated by people and the behaviors and characteristics of animal species (both native and introduced) lead to important scientific and management problems.
Concerted effort to monitor, analyze, and record sightings of non-native (introduced) aquatic species throughout the United States. Explains characteristics of the database that is compiled by this program.