Hunting has an obvious—and direct—effect on the population of the targeted species. But scientists are increasingly interested in hunting’s indirect effects. For instance, hunted mule deer are known to move into less desirable habitats, and their poorer diet can affect their ability to successfully reproduce. Now, a team of scientists studying Scandinavian brown bears (Ursus arctos) reveals that hunting disrupts the bears’ society, leading to more deaths. Over a 21-year period, from 1990 to 2011, a team of scientists tracked 180 female bears and their cubs in a 13,000-square-kilometer area of boreal forest in south-central Sweden. Hunting here is the primary cause of mortality for bears that are 1 year old or older. During the bear hunting season, which begins in late August and runs through mid-October, people are allowed to kill any solitary bear they encounter, male or female. Only females with cubs are not targeted. But this does not mean that the cubs will survive, the scientists report online today in the Proceedings of the Royal Society B. That’s because male Scandinavian brown bears are territorial and infanticidal. When a resident male that fathered cubs is killed, he is usually replaced by an unrelated male. If he can, the new male will kill these youngsters so that the females in his area become sexually receptive. Nearly 81% of all cub mortality occurred during the mating season of the study period, the scientists say, and “most, if not all” of these deaths were due to infanticide. These indirect effects should be considered when wildlife managers are establishing hunting quotas and policies, the scientists say.