捕食者と被捕食者の相互作用

All organisms need energy to survive. For example, gazelles are herbivores that feed on plants. On the other hand, cheetahs are carnivores that hunt gazelles. This predator–prey interaction is called predation, in which the cheetah acts as the predator and gains energy by consuming the gazelle, its prey.

A predator uses a range of sensory adaptations to detect prey, depending on the species. These may include sight, smell, and hearing. Specialized physical features, such as teeth or claws in cheetahs, allow the predator to capture and consume the prey.

As prey evolve traits to avoid predation, predators also evolve traits that improve hunting success, such as the cheetah’s increased speed.

For example, some birds have evolved exceptional eyesight, including color vision, which helps them locate and hunt prey. A defense called crypsis helps prey avoid visual detection by blending into their environment. For example, peppered moths have colors and patterns that match the bark and branches of their host trees.

In other cases, prey do not hide. For example, monarch butterflies show their toxicity with bright, patterned wings. This warning coloration, called aposematism, acts as a visual cue to predators that the butterfly is harmful or inedible. Birds that ignore this warning experience a bad taste or nausea and later avoid similar butterflies.

When a species’ warning coloration works well, other species that face the same predators may evolve to copy its appearance.

One such pattern is Müllerian mimicry, in which species that are toxic or unpalatable to predators evolve similar warning signals and both benefit as predators learn to avoid them. Viceroy butterflies, for example, are toxic and closely resemble monarch butterflies. When predators try one species, they learn to avoid the other species rather than risk another unpleasant feeding experience.

Alternatively, Batesian mimicry happens when a harmless species mimics a harmful species. For instance, predators avoid the bright, tricolor banded pattern of venomous coral snakes. Nonvenomous king snakes benefit from this pattern by mimicking the coral snake’s appearance.

Predator-prey interactions resemble an evolutionary arms race, driving the evolution of adaptations in both predators and prey. This mutual evolutionary change between interacting species is called coevolution.