How wolves
changed Yellowstone National Park
In 1995,
wolves where reintroduced to Yellowstone National Park. They had been absent
for 70 years. The elk and deer population was big since no other animals where
there to cut it down. The deer ate all the grass in the valleys and gorges so
no grass or flowers lived there.
When the
wolves arrived, they didn’t just kill some deer, the deer moved away from those
valleys which lead to the growth of grass and flowers. The trees became taller
which brang in plenty of different species of birds. Beavers came in to live
there since they ate the trees. They created dams and niches which allowed other species such as muskrates and
otters to live in. The wolves killed the coyotes so the number of rabits and
mice went up, which gave life to more hawks and eagles.
The wolves
didn’t just change the Yellowstone National Parks ecosystem but also its
physical appearence; the wolves changed the rivers. More trees started to grow
close to the river banks, reinforcing the banks. The banks stopped collapsing
so the river was healthier and wider.
The wolves
kept the Yellowstone National Park alive by changing the ecosystem and its
physical appearance.
Questions:
1. Do you know another animal that
changed the ecosystem or physical appearance of an area?
2. How do you think the wolves kept the
park alive in a way?
