Decision Making in a Changing Climate - World Resources Institute

Bear density appeared to be higher on the NSA (17.0/100km 2 ) than theSSA (9.4/100km 2 ), but the sex-age composition was very similar for the 2 studyareas. Adult females constituted approximately 30% of study populations andadult males accounted for 15-19%. Annually, relative proportions of yearlingsand subadult males appeared to vary the most.Using the habitat model, we predicted suitable black bear habitat acrossapproximately 58,939 km 2 (14.6 million acres), of which 75% was comprised ofprimary cover types. Nearly 50% of the predicted suitable bear habitat wasmanaged by the U. S. Forest Service, 33% was under private ownership, andtribal lands comprised about 10% of the area. Statewide, 17% of predicted bearhabitat was within 5 km of human-populated areas. Although currently based onrelatively coarse data, the model was constructed so that future, more resolvedinformation can be easily incorporated to update model predictions.Extrapolating observed density estimates to areas of primary habitatyielded a statewide population estimate of 5,947 bears 1 year old. Thisestimate was similar to the independent estimate of 5,200 derived frompopulation modeling for the state (excluding the Zuni, Mt. Taylor,Sandia/Manzano, and Chuska regions). These estimates refute the previousestimate of 3,000 bears used by the NMDGF, however they do not suggest adoubling of the bear population in the past decade. Rather, these estimates arebased on better information and, as such, are more reliable.Analyses of harvest data from 1985-1999 indicated bear hunters in NewMexico consistently harvested more males than females. The female proportionof annual statewide harvest ranged from 29 to 46%. Total annual bear kill byhunters was affected by many factors including season timing, hunter effort,hunter method, and mast production, as well as underlying populationcomposition. Hunters aided with dogs had higher success rates and harvested 4times as many female bears per hunter as those not using dogs. Later fallseasons were associated with lower total harvest and lower proportions offemales in the harvest, compared to earlier fall seasons and spring seasons.Failures in oak production were associated with increases in hunter effort, huntersuccess, and the proportion of females in the kill.Accuracy and consistency of the cementum annuli aging techniqueappeared adequate for assessing the age composition of annual hunter-killedbears and reporting of sex appeared to be accurate. However, analysesindicated harvest data were incomplete, underestimating the annual bear kill byas much as 7%.The bear population model was designed to simulate a black bearpopulation through time, with biological realism, hunting, and environmentalinfluences. Using observed reproductive and survival rates, modeling indicatedstudy populations were either stable or slightly increasing. Future utility of theBlack Bear Study in New Mexico v Final Report - 2001