1836 What Were Learning About Black Bears in - webapps8

What We're LearningAbout Black Bearsin MinnesotaBears in north-central Minnesota producemore robust cubs than those in northeasternMinnesota. Why is this so? Two DNR wildlifebiologists report on black bears they havestudied over the past three yearsKaren Noyce and Dave GarshelisPICKING OUR way through winterbrittlealder and squeakingsnow, we approached the den with acertain anticipation. Twenty feetfrom the mound of dirt marking theden entrance, we stopped. Last yearthis bear, female #400. was alert inher den, making it difficult to getclose enough to administer the immobilizingdrug. But last year shehad year-old cubs. This Decembershe should be pregnant with a newlitter. Based on previous experiencewith pregnant females, we expectedher to be soundly asleep.We were still 10 feet away whenwe heard the telltale pop-pop of herjaws and the heavy breathing characteristicof a not-too-pleased bear.There she was, head up, staring usstraight in the eye, and looking notthe least bit groggy from her eightweeks of rest. So much for ourtheory about pregnant females.It has taken three winters ol visitingbear dens to learn a simple lesson:Some bears sleep soundly,whereas others are more wary intheir dens, regardless of sex, age, orreproductive status. It will requiremany more years to answer importantquestions: How many cubs areborn each winter? How many surviveto adulthood? What factors influencerates of reproduction andAbove: In spotter plane, observer Karen Noyce locates radio-collared bearsby telemetry. Directional antenna is on wing strut at right. Left: Branchholds jaw of drug-immobilized bear open. (Color photo by Tim Smalley, DNR.)37