Which of the following examples poses the greatest potential threat to an ecosystem’s biodiversity? a) Abandoned farmland is allowed to go fallow and begins to fill in with weeds, shrubs, and saplings.
b) A nonnative species of bee is introduced to prey on the introduced species of fire ants in the Southern United States.
c) A monoculture of fir trees is planted on land that was once clear cut from deforestation.
d) The trapping and relocating of wolves poses a threat as they move into areas of high human population.

Monarch butterflies have brightly colored orange wings with black patterns on them, making them easily visible to birds that eat butterflies and moths, yet birds rarely eat the monarchs. likewise, the monarch caterpillars are brightly striped yellow and white and black, and they also are rarely eaten by birds, although some wasps will attack them and feed them to their young. what can be inferred from these observations? monarchs must threaten and attack birds, but not wasps. monarchs have a way of discouraging bird predation that does not involve hiding. monarchs’ wings are so colorful that most birds must find them difficult to eat. monarchs lay more eggs than other less conspicuous butterflies.