The wolves of Yellowstone
Fifteen grey wolves were introduced into the Yellowstone ecosystem in 1995. At that time, there was only one beaver colony there. This spring, a slap echoed throughout Yellowstone national park, a beaver slapping its tail on water which served as a warning to other beavers. This sound is growing more common by the day. As of present, there are now nine colonies of beavers, which indicates how introducing wolves into the ecosystem has changed the national park drastically. The change has been welcoming and thriving.
The change has astounded biologists who have been doing multi-fold research to understand and comprehend this change. The presence of wolves triggered a series of drastic changes in both animals and plant communities. To one of the biologists, “It is like kicking a pebble down a mountain slope where conditions were just right that a falling pebble could trigger an avalanche of change.”
In the 1930s, the wolf was killed off in Yellowstone, and the elk population grew tremendously. Although they were still preyed upon by grizzly bears, cougars, and events, the absence of wolves took much predatory pressure off the elk. As a result, the elk pushed the carrying capacities of the national park, and they did not migrate in winter, which further damaged the ecosystem. Young willow, aspen, and cottonwood plants were heavily consumed by the elk, which disrupted the ecosystem.
Beavers survived on willow, and their absence was tough on their colonies. The willow stands along the streams were in bad shape when elk were the third of what they are today. However, the elk today are significantly in numbers, but the willow stands are thriving. Why? Because the wolves provided the necessary predatory pressure on the elk, so they remained on the move constantly and never settled.
And when the willow stands thrived, they provided an abundant food source to the beavers, and they grew in numbers. As the beavers spread and built new dams and ponds, the cascade effect continued.
Biologists rarely get a chance to research the effects of what happens when a key specie is introduced back into the ecosystem. It is the most natural phenomenon. Initially, it was feared that wolves might wipe out the elk population altogether; however, the return of the grey wolves has proved to be more of a stabilized force. Wolves reduced populations and thinned out weak and sick animals, which eventually led to the creation of more resilient elk herds. Wolves primarily kill older elk as they are the easiest to prey upon.
Since the reintroduction of wolves in 1995 in Yellowstone national park, the impact on plant and animal life has been quantified and studied. The wolves ended up stabilizing the ecosystem of the national park. The data derived from this research will further help biologists in providing valuable lessons in the reintroduction of animal species in an environment.
Today there are almost 500 wolves present, all of whom are descendants of the 41 wolves
introduced between 1995 to 1997. There are 30 different packs, and 18 are being extensively
monitored. The wolves are being studied by VHF (very high frequency) radio collars around
Researchers argue that with fewer elk populations and the added worry about the wolves, elk
tend to stay away from tree species like willow and aspen. Moreover, they create fewer
disturbances in the habitats of the animals. Less trampling and feeding in certain areas even
changed the physical geography of Yellowstone. The stabilized ground minimizes erosion and enables
the vegetation to grow in different places.
This change has been fruitful in many ways and is known as the ‘trophic cascade,’
essentially the modifications brought by animal and plant species. The park is now healthier for animals and more ecologically diverse. The data provides a lot of helpful knowledge
for the future reintroduction of animals in several different ecosystems. Given the positive
benefits of this ecosystem, scientists are now reintroducing wolves in other areas, such as in
Europe where wolves have been gone for a hundred years.
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