The bird and beaver population increased when the wolves returned because it scared the deer off into certain places, letting places regenerate, allowing vegetation to regrow, attracting birds because of the nice environment, as well as the beavers because they like to eat trees.

The population of grass in the park was so drastically reduced in the absence of the wolves because the deer population grew too quickly due to there being no predators, so then the large amount of deer needed a lot of food, so they grazed away almost all the vegetation, and the population of grass was reduced drastically.

One reason for the increase in the populations of hawks, weasels, foxes, and badgers after the wolves returned to the park is that the wolves killed the coyotes, attracting rabbits and mice to live there, then attracting hawks, weasels, foxes, and badgers, increasing their population.

The rivers meandered less, there was less erosion, and more pools and riffle sections formed, all changed in response to the presence of wolves. This is because the wolves scared away the deer to certain places, letting many forests regenerate, and those forests stabilized the banks so that they collapsed less often and so that there was less soil erosion.

The populations of rabbits and mice started to increase after the wolves returned to the park because the wolves killed coyotes, which fed on the rabbits and mice. So with fewer coyotes appearing, the populations of rabbits and mice increased.

Q2. This is because the deers didn’t have predators, therefore their population increased severely having more deers feed on grass.

Q3. This is because the mice were introduced to the environment because there is grass to eat causing the increase in population of hawks, weasels and foxes.

Q4. This is because due to the wolves, therefore their population beavers got to build dams without being bothered.

Q5. This is because the food supply was increased.

The wolves helped drive the deer away from the places they could get cornered which led to shrubs and trees growing there to thrive. As the video said, the beavers could eat the trees and the trees also act as a home to build nests.

Q2: Explain why the population of grass in the park was so drastically reduced in the absence of the wolves.

The population of deer was not balanced in Yellowstone National Park, the deer's diet is grass so as the population of deer increased, the population of grass reduced as it was eaten by the deer.

Q3: Give a reason for the increase in the populations of hawks, weasels, foxes and badgers after the wolves returned to the park.

After the wolves returned to the park, the population of rabbits and mice grew in the park which led to predators such as hawks, weasels, foxes and badgers increasing in population.

Q4: Interactions between the living and the physical factors in an environment--> Why did the rivers change in response to the presence of the wolves?

As the forest thrived, the banks were stabilised and were more fixed on their course.

Q5: Why did the populations of rabbits and mice start to increase after the wolves returned to the park?

The wolves killed the mice's and rabbits predators such as coyotes which led to their growth in population.

because there are no predators of the deers, therefore they will just keep on eating the grass, causing a decrease.

As there are more mice and prey for the hawks.

There were more dams built by beavers, therefore it changed the river's course.

The wolfs helped kill one of the predators of rabbits and mice which increased the population of the rabbit and mice.

Question 2: The deer population went out of bounds and they kept on eating and eating the grass and other vegetation that there were too many deers and not enough time to spread, therefore the grass drastically reduced before the wolves came back.

Question 3: The deers avoided the parts where they can be easily hunted down, and later, other predators started hunting them down too, and vegetation regenerated, therefore the beavers that like to eat them started moving in, and then there was also more habitat for foxes, mice and other small animals came back and the hawks came to hunt them to eat, and weasels made use of the habitat the beavers builds for them that are also dams.

Question 4: The vegetation returned, therefore more plants stabilized the soil so there was less soil erosion, and the rivers then went back to normal as there was less loose soil, hence the rivers changed in response of the presence of wolves. (chain reaction)

Question 5: The more plants and trees gave the small animals more space to get a good habitat, parts of the park became suitable for them to settle, and therefore there were Moore burrows they can create and reproduce, as the surrounding food increased as the deers’ population reduce.