Resource Availability in Ecosystems

Hawks and brown bears live together in the same habitat. There will be competition between the hawks and the brown bears only if which of the following is true?

• Brown bears hibernate during the winter while hawks remain active.

• Pesticides in the fish population affect hawks’ eggs and decrease their population.

• Both brown bears and hawks feed on the same species of fish.

• Both Shanna and Savanna feed on the same species of snakes.

The population of deer in a certain area is monitored over a period of six years. The data is represented in the graph provided. Which of the following is the most likely explanation for the change in population in 2009?

• Wild dogs, which prey on deer, were being hunted more than usual.

• Snowfall in the previous spring was higher than the yearly average.

• Humans introduced grazing animals that feed on the same plants as the deer.

• More insects that pollinate flowering plants move into the ecosystem.

An increase in which of the following factors is likely to contribute to competition between two members of the same species living in a certain habitat?

• Available food resources

• Population of the species

• Annual snowfall

• Overall size of the habitat

A simple food chain includes hawks, lizards, and insects. Which will MOST likely happen to the lizard and hawk populations if a pesticide is sprayed to kill the insects, and the lizard and hawk populations cannot find other food in this ecosystem?

• Both the lizard population and the hawk population will decrease

• Both the lizard population and the hawk population will increase.

• The lizard population will increase, but the hawk population will decrease

• The lizard population will decrease, but the hawk population will increase

What happens to the population of wolves if the population of rabbits increase?

• The population of rabbits will keep increasing.

• An environmental factor that puts limits on organism's population

• The relationship of two species that live in close with each other

• The population of wolves will increase.

What happens to the population of bats if we cut down all the trees?

• One organism benefits and the other is harmed

• The relationship of two species that live in close with each other

• The population decreases.

• Living factors like plants and animals

If a species survival rate is high, how does that affect population and reproduction rates?

• Reproduction rates would increase causing population to increase

• Reproduction rates would increase causing population to decrease

• Reproduction rates would decrease causing population to increase

• Reproduction rates would decrease causing population to decrease

If a species survival rate is low, how does that affect population and reproduction rates?

• Reproduction rates would increase causing population to increase

• Reproduction rates would increase causing population to decrease

• Reproduction rates would decrease causing population to increase

• Reproduction rates would decrease causing population to decrease

If resource availability is high, how does that affect competition and population?

• Competition will increase while population increases

• Competition will increase while population decreases

• Competition will decrease while population increases

• Competition will decrease while population decreases

If resource availability is low, how does that affect competition and population?

• Competition will increase while population increases

• Competition will increase while population decreases

• Competition will decrease while population increases

• Competition will decrease while population decreases