MADISON July 1 marks the beginning of the three-month summer deer observation (pdf) period during which DNR biologists, foresters, property managers and staff, wardens and staff from the U.S. Departments of Agriculture and Forest Service record the deer they see as they go about their daily duties. The observations are one of many factors biologists use in developing deer population estimates and monitoring herd health.
Summer deer observations are one of many factors biologists use in developing deer population estimates.
Direct observations from the field are vital information for deer managers, especially in northern and central forest deer management units (DMU) where harsh winter weather can have a much greater impact on fawn production the following spring. In the northern and central forest regions observations are bunched into "population modeling" groups of 3 to 4 DMUs each and plugged into the department's deer population estimating model. Each summer fresh observation data are put into the population estimation.
"Wildlife populations are estimated by blending science, hunter harvest, history and observation," said Keith Warnke, DNR deer and bear ecologist. "Variations in local habitat and conditions, and nature's whims make this challenging and it's important to keep in mind that these are estimates. Deer movement and location are influenced by many factors beyond population numbers."
In addition to DNR staff summer field observations, the department also mails a summer wildlife inquiry (pdf) to about 5,000 rural landowners across the state. The landowner survey is not incorporated directly into population models but is compared to previous years as a signal of broad population trends.
The summer wildlife survey asks respondents to report observations of nine species of wildlife including coyote, red fox, skunk, bobcat, wild turkey, gray partridge, ring-necked pheasant, ruffed grouse and deer.