Competition in Ecosystems

Hawks and owls eat the same type of food and struggle with one another to get their food. What is this an example of?

• Competition

• Biotic factor

• Symbiosis

• Population

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A graph shows a forest ecosystem where gray squirrel population declined after red squirrels were introduced, both competing for acorns. Which evidence best evaluates interspecific competition as the primary cause over intraspecific competition?

• Red squirrels have broader diets, reducing acorn dependence for grays

• Gray squirrel numbers dropped sharply while red numbers rose, indicating resource overlap

• Acorn production increased that year due to favorable weather

• Both species nests were similar, but predation was unchanged

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Synthesize a model predicting competition outcomes in a pond: Ducks and fish both consume aquatic insects (limited). Design the best intervention to reduce competition while maintaining ecosystem balance.

• Add more plants to increase insect production via habitat

• Remove all ducks to favor fish growth

• Introduce a predator only for ducks

• Stock more insects artificially every month

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A desert ecosystem has cacti and shrubs competing for scarce water. Synthesize a prediction model for population changes if rainfall halves: Which factor integrates competition type and outcome?

• Cacti (deeper roots) outcompete shrubs via interference, leading to shrub decline

• Both shift to mutualism, sharing water equally

• Shrubs evolve new leaves for less water use

• Predators increase, ignoring water competition

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Evaluate this claim: "Intraspecific competition is always more intense than interspecific in ecosystems." Which scenario best refutes it using resource data?

• Deer herd overcrowding limits grass for all equally (intraspecific)

• Invasive kudzu vines outcompete native plants for sunlight despite less niche overlap (interspecific)

• Lion prides defend territories fiercely (intraspecific)

• Oak trees drop acorns yearly, sustaining squirrels (no competition)

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Data: In a lake, algae bloom reduces oxygen; fish population crashes while Daphnia (plankton-eaters) thrive temporarily. Evaluate why competition intensified post-bloom.

• Fish and Daphnia competed intraspecifically for remaining oxygen

• Algae competed with fish for space, but Daphnia adapted

• Reduced oxygen limited fish more (higher demand), favoring Daphnia via interspecific exploitative

• Bloom increased predators, unrelated to resources

An organism that gets its energy by feeding on producers in the food chain

• Primary Consumer

• Secondary Consumer

• Apex predator

• A lion

Synthesize a grassland management plan combining intraspecific and interspecific competition to sustain bison and prairie dogs sharing burrows/grass. What key strategy balances both?

• Rotate grazing to limit grass overuse by bison, reducing pressure on prairie dog food

• Remove prairie dogs to eliminate all competition

• Fence burrows for prairie dogs only

• Add wolves to prey on both equally

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Evaluate invasive zebra mussels' impact in a river: They filter plankton faster than native clams, causing clam decline. Which criterion heavily weights interspecific competition over predation?

• Mussels reproduce faster, outpacing clams naturally

• Shared resource (plankton) depletion shows exploitative overlap, not direct killing

• River flow changes unrelated to mussels

• Birds eat more clams post-invasion

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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.

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