More on the impacts of hunting trophy male predators as it relates to population declines --when dominant males in a territory are killed by hunters, the result is that younger males move into the territory and kill the offspring of the previous resident dominant male

Unintended results of killing older male predators

Rob Wielgus
Rob Wielgus, a wildlife ecologist, started monitoring grizzly bears while in graduate school in Idaho in the early 1980s. He determined that when older males were hunted and removed from the ecological system, a social disorder resulted that threatened the survival of the remaining bears.
It didn't take him long to realize the same notion might apply to other large predators. "It looked like it was any solitary carnivore that had extended parental care," he says. He widened his focus to include cougars, black bear, and lynx.
Studying cougars in a specific area from the late 1990s until the early 2000s, Wielgus and his team of students found that while cougar sightings had steadily increased, the population, in fact, had declined at a rate of more than 10 percent per year. Hunters were going after the senior males and causing social disorder.
Wielgus's findings contradicted the common notion that increased sightings meant an increasing population. In fact, says Wielgus, it's the opposite. An older male will protect his territory, do his best to stay out of view, and preserve a social order that provides his mates the years they need to raise their kittens. If he's gone, juvenile males will move in and kill his kittens, further reducing the population, particularly damaging the female population. Without an older male to keep them in check, in their new territory the juveniles will also chance more human and livestock encounters.
This work has changed hunting and wildlife management policies in the United States and Canada. At one time governments allowed for more hunting when there was an increase in human-cougar or human-bear encounters. Now in Washington, Oregon, and British Columbia the hunting of these large predators has been restricted. Based on Wielgus's findings, British Columbia has created seven grizzly bear preserves.
Wielgus directs the Large Carnivore Conservation Lab at WSU with the mission of helping maintain healthy predator/prey communities in the Pacific Northwest and around the world. He and his students and post-docs have studied cougars in the Washington, grizzlies in British Columbia, and brown bears in Europe. Now his students and other researchers who have studied his work are noting how this same behavior applies to large predators world-wide, including leopards, tigers, and cheetahs.