Karels, T.

11 items:

The role of red squirrels and arctic ground squirrels Categories: Publication; Types: Citation; Tags: M1-Mammals
The role of red squirrels and arctic ground squirrels Categories: Data, Publication; Types: Citation, Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: Mammals, Monitoring 1-Changes in Plant and Animal Distribution: Fauna
Concurrent density dependence and independence in populations of arctic ground squirrels No population increases without limit. The processes that prevent this can operate in either a density-dependent way (acting with increasing severity to increase mortality rates or decrease reproductive rates as density increases), a density-independent way, or in both ways simultaneously. However, ecologists disagree for two main reasons about the relative roles and influences that density-dependent and density-independent processes have in determining population size. First, empirical studies showing both processes operating simultaneously are rare. Second, time-series analyses of long-term census data sometimes overestimate dependence. By using a density-perturbation experiment on arctic ground squirrels, we... Categories: Publication; Types: Citation; Tags: Mammals, Monitoring 1-Changes in Plant and Animal Distribution: Fauna
Concurrent density dependence and independence in populations of arctic ground squirrels No population increases without limit. The processes that prevent this can operate in either a density-dependent way (acting with increasing severity to increase mortality rates or decrease reproductive rates as density increases), a density-independent way, or in both ways simultaneously. However, ecologists disagree for two main reasons about the relative roles and influences that density-dependent and density-independent processes have in determining population size. First, empirical studies showing both processes operating simultaneously are rare. Second, time-series analyses of long-term census data sometimes overestimate dependence. By using a density-perturbation experiment on arctic ground squirrels, we... Categories: Publication; Types: Citation; Tags: M1-Changes in Plant and Animal Distributon, M1-Mammals
Concurrent density dependence and independence in populations of arctic ground squirrels No population increases without limit. The processes that prevent this can operate in either a density-dependent way (acting with increasing severity to increase mortality rates or decrease reproductive rates as density increases), a density-independent way, or in both ways simultaneously. However, ecologists disagree for two main reasons about the relative roles and influences that density-dependent and density-independent processes have in determining population size. First, empirical studies showing both processes operating simultaneously are rare. Second, time-series analyses of long-term census data sometimes overestimate dependence. By using a density-perturbation experiment on arctic ground squirrels, we... Categories: Publication; Types: Citation; Tags: M1-Changes in Plant and Animal Distributon, M1-Mammals

ScienceBase brings together the best information it can find about USGS researchers and offices to show connections to publications, projects, and data. We are still working to improve this process and information is by no means complete. If you don't see everything you know is associated with you, a colleague, or your office, please be patient while we work to connect the dots. Feel free to contact sciencebase@usgs.gov.