THE BEARS

Black bears currently being studied in the Wisconsin Black Bear Research Project are located in three main areas; The Chequamegon-Nicolet National Forest in the Clam Lake area, the Hanson Forest area, and the Ashland area. Research from the past two decades has included other areas in northern Wisconsin.

In the Clam Lake Area, there are 4 adult sows and 5 sub-adult females who will be 2-years-old in 2003. There is one remaining adult sow on the Hanson Forest who should have 2 female yearlings and 1 male yearling, an orphan from 2002.

One bear in the Ashland High School project�Bear No. 184--was originally part of Ray Anderson's reproduction/productivity research.  She had 4 cubs last year. There are several other bears being studied in the Ashland project.

Black bears are mature at 3 years of age. Females breed every other year from then on, giving birth to two to three cubs while still in the winter den. The cubs first leave the den with their mother late in March. The family stays together through the summer and the following winter denning. In the spring, the sow will chase the cubs off so she can breed again.

HOW THE BEARS ARE STUDIED

Researchers and volunteers collect data on bears primarily in two ways. The first is to sedate denned or captured bears. It is not necessary to sedate cubs since they are not aggressive.. Bears are weighed, monitored for heart and respiration rate and temperature.  The sex of each bear is determined. Chest girth, total length, neck girth, and footpads are measured.  Cubs of the year are also sexed and weighed.  A first premolar tooth is extracted from all bears of unknown age, and sent to a lab for age determination.  The bears are marked with button ear tags and tattooed inside the lower lip with a permanent ID number.   

The second way bears are studied is through radio transmission technology. Radio-transmitter collars equipped with a motion-sensor device that signals inactivity and possible death are attached to most sedated bears. There are two collar sizes: one for adults and one for yearlings. Collars are equipped with leather spacers designed to break away after 18 months to preclude injury in the event that researchers wouldn�t be able to gain access to a bear before the bear outgrows the collar. In the first den visit after transmitter placement the leather spacer is replaced; the second winter a new transmitter is attached and den characteristics are also described and measured.

Monitoring of radio-collared bears is done every other weekend during the summer. The bears are monitored more closely during den emergence and later in spring when yearlings separate from their mamas. After the gun deer season is over, more defined locations are taken to determine winter den locations.  After the Christmas holidays, dens are located and marked. Researchers determine whether cubs are present by listening for cub vocalizations.

Hunters help the study by turning in collars and tags from bears they harvest. In turn, project volunteers  provide hunters with a history of the tagged bear.

 

Scientists and volunteers in the Wisconsin Black Bear Research Project have gathered some interesting facts from the bears they study.
  One adult sow took a liking to her winter digs and used the same den 5 out of 7 years.
  Typically, only 4% of dens are reused and only a small percentage used by the     same bear.
  Another den revealed an adult sow, two 2-year-olds, and a cub.
  The largest boar in this research was 678 pounds at the ripe age of 21or 22.
  One sow bred at age 2-1/2 (24% breed this early) and     her cub was the only cub in the research with a silver color phase.
  A Stockton Island MacArthur boar (from early research) boarded a sailboat and went in the Ranger Quarters. The Park Service trapped him in a culvert trap and moved him to the mainland where he wandered around for a while before heading NE back to Stockton Island.  The next year he came to the mainland on his own.

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