Reviews of Yellowstone Park records and other data showed that artificial food altered the natural habits of grizzly bears (Ursus arctos) and was basically responsible for most bear injuries to humans. A management program was implemented to (1) restore grizzlies to using natural foods entirely, and (2) reduce injuries from the relatively high levels attained during the 1960s. The program involved eliminating artificial food sources and selectively removing certain bears from the population. These were mainly animals that habitually visited campgrounds to obtain food and returned from transplants. The preliminary 1970 and 1971 results from the program suggested that initial trends were occurring in restoring a more natural grizzly population and reducing injuries to humans. The numbers of bears removed from the population each year were less than the production of cubs. Considerations of the logistic growth equation suggested that these removals could temporarily reduce emigrations, but were not of sufficient magnitude to prevent the park?s grizzly population from either maintaining or rapidly reestablishing its numbers at carrying capacity levels.

A management program to reduce grizzly bear (Ursus arctos horribilis) injuries to humans and maintain bears under more natural conditions is evaluated. Tests of collected data against hypotheses permitted the initial conclusions that from 1970-1973 management significantly reduced injuries from previous levels, made measurable progress toward restoring a grizzly population that lived under more natural conditions and did not prevent the population from replenishing its numbers by its yearly production of young. -- Abstract from unpublished report.