Organisms and Their Ecosystems. Have you ever heard of the zebra mussel? It was accidentally brought to the Great Lakes from Europe, probably on the bottom of a boat.
If you are a prey, fast leg muscles are useful to help you escape from your predator. A rabbits good hearing helps to warn it. An arctic hare has white fur in winter, in the snow, but brown in the summer, like dirt.
Mice, Snakes, and Hawks escape from your predator. A rabbits good hearing helps to warn it. An arctic hare has white fur in winter, in the snow, but brown in the summer, like dirt.Imagine an ecosystem with mice, snakes and hawks. If a disease kills most of the mice in this ecosystem, the snakes will have less to eat. When they die, there are less snakes reproduced. Then the hawks will have to look elsewhere for food or die, too.
Environmental factors that cause the populations in ecosystems to change are called limiting factors. Water food, space, weather, and pollution are all examples of limiting factors.
EXAMPLES: Drought, construction, polluted soil and water.
Some organisms will die, and their populations will go down.
Fish don’t live in the desert because they need water.
Frogs need moist, warm environments and water to lay eggs.
Reptiles can handle limiting factors of dry, hot habitat
It is important to remember that the living things in an ecosystem are there because their characteristics and needs match what that ecosystem has to offer. If something in that ecosystem changes, then those living things will have to hope that they are able to handle the change. If not, they won’t be found in that ecosystem much longer.
The lynx is a predator to the snowshoe hare. This graph shows the relationship between the lynx and the snowshoe hare populations over many years. In 1855, the number of snowshoe hares started to go up. Maybe something in the ecosystem changed to make it easier for snowshoe hares to find food or reproduce.
What happened to the population of lynx at this same time? It went up, too. Why? Most likely it was because there were more snowshoe hares around and the lynx had more food and could survive better. The reverse happened in 1885. The number of hares started going down for some reason. Maybe hunters killed them, or humans built homes in their habitat. With less food around, the lynx population went down too.