Concentration Definitions.

*Concentration Area Definitions*	*BLM Land Status Map Legend*


Resident Population An area used year-round by a population of elk. Individuals could be found in any part of the area at any time of the year; the area cannot be subdivided into seasonal ranges. It is most likely included within the overall range of the larger population. Not all units have a resident population. Summer Concentration Those areas where elk concentrate from mid-June through mid-August. High quality forage, security, and lack of disturbance are characteristics of these areas to meet the high energy demands of lactation, calf rearing, antler growth, and general preparation for the rigors of fall and winter. Summer Range That part of the range of a species where 90% of the individuals are located between spring green-up and the first heavy snowfall. Summer range is not necessarily exclusive of winter range; in some areas winter range and summer range may overlap. Winter Range That part of the overall range of a species where 90 percent of the individuals are located during the average five winters out of ten from the first heavy snowfall to spring green-up. Winter Concentrations That part of the winter range of a species where densities are at least 200% greater than the surrounding winter range density during the same period used to define winter range in the average five winters out of ten. Severe Winter Range That part of the range of a species where 90 percent of the individuals are located when the annual snowpack is at its maximum and/or temperatures are at a minimum in the two worst winters out of ten. The winter of 1983-84 is a good example of a severe winter. Migration Corridor A specific area through which large numbers of animals migrate and loss of which would change migration routes. Production Area That part of the overall range of elk occupied by the females from May 15 to June 15 for calving. Where did the map data come from? The Natural Diversity Information Source, NDIS, a Division of the Colorado Division of Natural Resources. NDIS has an ongoing study with over 12 years of continuous monitoring and tracking wildlife. The concentration maps are updated on a 5 year cycle.