Hunters wiped wolves out of the Yellowstone National Park years back. However, they were reintroduced in 1995, and their impact on the park is remarkable. According to the video, the wolves created a trophic cascade—an ecological process that starts at the top of the food chain and trickles down to its bottom (Sustainable Human, 2014). All the trophic levels were affected, beginning with the decline in consumers such as coyotes and Wapiti deer to the increase of others like birds. Consumers are all the animals that feed on other animals or plants for energy. Wolves were introduced as consumers at the highest trophic level of the park. As they fed on other consumers, mainly the deer and coyotes, their population and behavior changed (Sustainable Human, 2014). Large grazers such as the Wapiti deer feed on producers around the park.
Producers use abiotic factors, including sunlight, water, and air, to create their food in terms of organic molecules. The Yellowstone National Park producers include trees, shrubs, and grass. Wolves reduced the population of deer and coyotes, leaving fewer grazers in the park (Sustainable Human, 2014). In addition, the deer’s behavior of grazing and movement around the valleys changed as they hid from wolves. Therefore, the riverbanks and vegetation in the valleys grew as trees also became taller. The growth of the vegetation led to a succession in the park, which attracted new species and animals, including birds. Increased vegetation also reduced soil erosion around the riverbanks, leading to less meandering, deepening of channels, and formation of small pools (Sustainable Human, 2014). In addition, the river provided shelter to amphibians, fish, and reptiles. Therefore, the wolves transformed the park’s physical geography, biodiversity, and entire ecosystem.
Reference
Sustainable Human. (2014). How wolves change rivers [Video]. YouTube. Web.