How the Wolves Change the Forest
Literally get down on our hands and knees and starts slowly sifting through the leaf litter looking for bissett hair or a little chunk of bill. Tom gabel is tracking predator. In fact he's tracking pack of them. Oh it's very much like a crime scene investigation since twenty fifteen the university of minnesota conservation. Biologists has used gps collars to track thirty wolves inside voyageurs national park. Those callers lead gable and his team to kill sites and they're amid the leaf litter were bloodied bits of fern bone clues about how wolves the ecosystems they live and hunt and kill in. The long-term study is in a way. A quest to broaden a science story that goes back twenty five years for wildlife ecologists the story of the reintroduction of wolves to the greater yellowstone ecosystem on january twelfth. Nineteen ninety-five has become canonical. The story goes something like this. As the elk grew to fear the wolves they changed where and how they foraged that gave willows cottonwoods and aspens a better chance to grow near streams it also meant more riverside berries for foraging grizzly bears and lead to alterations in the flow of those streams. Sending water in new directions. Wolves out compete coyotes for access to pray so coyote populations plummeted which led to a rise in fox rabbit and ground nesting bird numbers and so on ecologists called this row of biological domino's a trophic cascade regard with your inclination. I think it's hard not to be like. Wow this is amazing right if that is true. That's really incredible. New findings cast some doubt on the idea that wolves primarily regulate the greater yellowstone ecosystem through fear and intimidation and regardless of the situation. They're very little. Research has been conducted on this question. In ecosystems that don't resemble the mountains and grasslands of yellowstone which brings us back to the boreal forests of northern minnesota. The ground that tom gabel and his team have been crawling over the last few years during the winter. Wolves work together to kill large prey. Like dear but gable found than in warmer ice free months wolves focus on smaller prey like newborn dear funds and especially beavers and. That's where things get really interesting for the ecosystem. Wolves by trading on dispersing beavers alter where wetlands are created. If a young beaver gets killed after leaving home it will never have a chance to build a new dam even if it had started construction before becoming a wolf lunch. The damn will remain unfinished. End fall into disrepair beavers are ecosystem engineers so when a wolf kills one it can have a big impact because they prevent beavers from converting a forest into a wetland and in that regard wolves are unconnected to all of the ecological processes that are associated with wetlands and beaver ponds. Ecologists have long assumed that predators can influence their ecosystems in two main ways one is through fear and intimidation like in the yellowstone story. The second is through direct. Killing the voyagers will offer up a third possibility. The park and the forest surrounding it have more than seven thousand beaver. Ponds gable estimates that wolves have a direct impact each year on around eighty eight of them. That's a mere one and a quarter percent affected so it's hard to argue that wolves responsible for reshaping the ecosystem in the broadest sense. But it's equally hard to deny that. They helped to maintain a diversity of habitats landscape.