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Obtaining reliable estimates of absolute and relative reproductive rates is challenging for avian species whose nests are difficult to observe, such as the burrowing owl (Athene cunicularia). We compared methods for estimating reproductive rates of burrowing owls, defined as the number of 21- to 28-day-old young per Successful nest. We compared observations using (1) the mean and (2) the maximum number of young observed during 5 30-min observation periods, and (3) the maximum number of voting videotaped during 2-hr video surveillance. We evaluated the reliability of these methods with the known number of young present in nest boxes. All 3 methods performed poorly as estimators of absolute reproductive rates (absolute...
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This thematic map illustrates the projected annual compound population growth rate in the United States from 2010 to 2015. Total Population is the total number of residents in an area. Residence refers to the "usual place" where a person lives. This data variable is included in Esri's Updated Demographics (2010/2015). This map shows Esri's 2010 estimates using Census 2000 geographies. The map is designed to be displayed with 30–50 percent semi-transparency for overlay on other basemaps as noted in the map legend. A basemap with relatively few colors, such as Terrain, works well with this map when transparency is used. A web map that combines this service with the Terrain basemap and a reference overlay for...


    map background search result map search result map USA Projected Population Growth 2010-2015 USA Projected Population Growth 2010-2015