First, everyone wanted the wolves of Yellowstone National Park to be gone so all the grazing animals could flourish and tourism would not have to deal with them. The video below explains how an entire park could not flourish without it's a top-line predator.
By University of British Columbia
A team of researchers has determined the declining caribou population is part of a natural chain reaction from forest harvesting which can attract predators and competition for food
A new study comparing decades of environmental monitoring records (click here) has confirmed that Canada's caribou are not faring as well as other animals like moose and wolves in the same areas—and also teased out why.
The study used 16 years of data to examine changes in vegetation, moose, wolves and caribou. "Caribou are declining across Canada and have been recently lost in the Lower 48 States," says Melanie Dickie, a doctoral student with UBC Okanagan's Irving K. Barber Faculty of Science.
"Understanding why caribou are declining is the first step to effectively managing the species—it tells us which parts of the issue we can target with management actions and how that might help caribou."
Dickie, along with fellow UBCO researchers Dr. Clayton Lamb and Dr. Adam Ford, describe the decline in caribou populations as an ecological puzzle. Typically, there are multiple factors, all changing at once, making it hard to identify how the pieces fit together. Factors such as predation from wolves and other large carnivores, increasing moose and deer populations, and habitat alteration through resource extraction and wildfires all play a part. The study aimed to sort out the roles each of these play in caribou population declines.
Once land is cleared by either wildfire or harvesting, the mature forest transforms into more productive early seral forage. With the tree canopy removed, there is a significant increase in sunlight, allowing understory plants to thrive. These plants provide food that benefits moose, deer and their predators. These predators then have a spillover effect on the rarer caribou, creating apparent competition between moose and caribou.
"Changes in primary productivity have the potential to substantially alter food webs, with positive outcomes for some species and negative outcomes for others," Dickie explains. "Understanding the environmental context and species interactions that give rise to these different outcomes is a major challenge to both theoretical and applied ecology."...
