July 1 marks start of summer deer observation period

July 1 marks start of summer deer observation period

Weekly News Article Published: July 7, 2009 by the Central Office

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.

Farmland Regions

To people living in and traveling around Wisconsin it is not a surprise that there are ecological and climate differences between the southern farmlands and the northern forests.
In most years, winter weather simply doesn’t have the impact on southern deer in the way it does in the north. So in farmland regions biologists don’t adjust the fawn-doe ratio yearly like in the north, but they do analyze summer deer observations for trends that suggest a change in reproductive success in the herd. Also the population groupings contain more DMUs compared to the northern and central forests.

“Summer deer observations are important to hunters because the number of fawns per doe are one factor that is included in the population model,” explained Warnke, “that is why we collect this information. They are also an important factor in overall population management as deer management units approach established population goals.”

Wildlife managers emphasize that deer populations vary across the state with some areas heavily populated and others less so. Local population swings are not always predictable in the space of a single season and can result in lowered viewing opportunity in a given hunting area. Having a flexible hunting plan can be an important factor in a successful hunt.

“In areas where deer are at healthy levels, fewer deer may be seen than in the past when populations were out of balance with their habitats,” says Warnke. “The traditional hunter’s skills and strategies of scouting, patience, knowledge of deer behavior and woodsmanship are worthy of practice and perfection.”

FOR MORE INFORMATION CONTACT: Keith Warnke (608) 264-6023 or Bob Manwell - (608) 264-9248
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