Top-down control begins with predators and can cascade to lower trophic levels. Bottom-up control begins with producers or resources and affects higher trophic levels. Use food-web evidence to trace these changes.
Humans have persecuted predators such as coyotes (Canis latrans), causing severe reduction in the number of large carnivores throughout the world. The diagram represents part of a food web in Texas, USA.
What is a possible outcome for the lagomorph population in this ecosystem if coyote numbers were controlled by killing them to reduce losses of domestic livestock?
Decrease because there are fewer predators
Increase because there are fewer foxes to eat them
Decrease because there are more rodents for foxes to eat
Increase because, although there are more foxes, there are also more rodents