Brown bear conservation and the ghost of persecution past

Large carnivores, such as brown bears, are focal species for conservation efforts. Historically, brown bears were persecuted in Europe for centuries before their gradual elimination from much of Western Europe. In contrast, large carnivore populations in North America were eradicated within two centuries in the east and within a few decades in the west. After a change towards conservation-oriented management in the 20th century, many bear populations are again increasing on both continents. Europe is seemingly less suited (i.e. higher human densities, greater habitat alteration and landscape fragmentation) than in North America, however bears seem to respond faster to conservation measures in Europe. We analyzed ecological and historical factors that may affect differences in reproductive allocation (mean litter size in relation to mean adult female body mass) and help explain why different brown bear populations react differently to conservation measures. The results indicated that mean litter size increased significantly with mean adult female body mass and a long persecution history. Our results suggest that high and long-term rates of nonselective harvesting can change life-history traits of large mammals, as has also been shown by modeling, but only has been documented for morphological traits. Incidentally, this “ghost of persecution past” may have helped some brown bear populations to be more productive and therefore to respond more positively to protective management policies than populations with short exploitation histories.

► We model ecological and historical factors affecting reproductive allocation in bears.
► Bears in Europe were intensively persecuted for >500 years.
► Bears in North America were persecuted intensively for <150 years.
► European bear populations had larger litters than populations in North America.
► This suggests that long-term harvesting can change life-history traits of mammals.
► Long-term persecution may help bears to respond positively to protective management.