Question

prairie dogs are burrowing rodents that live in grasslands. what makes the prairie dog a keystone species in the ecosystem? 2 points a) prairie dogs are the main source of food for wolves and coyotes in the grassland. b) prairie dogs are the species with the largest number of individuals in the grassland ecosystem. c) they successfully compete with the other herbivores for grass and are a major threat to these species. d) their tunnels act as conduits for rain water to seep into the ground, thereby promoting the growth of grass.

Explanation:

A keystone species has a disproportionately large impact on its ecosystem relative to its abundance. Let's analyze each option:

• Option A: While prairie dogs are prey, being a main food source doesn't define a keystone species (keystone species impact ecosystem structure, not just food web as prey).
• Option B: Having the largest number of individuals makes them a dominant species, not necessarily a keystone species.
• Option C: Competing with herbivores negatively doesn't show a positive/structural impact of a keystone species.
• Option D: Their tunnels (a unique behavior) help water seep into the ground, promoting grass growth. This affects the ecosystem's physical structure and plant growth, which is a keystone - like impact (modifying the environment for other species).

Answer:

D) Their tunnels act as conduits for rain water to seep into the ground, thereby promoting the growth of grass.