R/K selection theory

In nature, animals have different strategies to survive and reproduce. R/K selection theory is a way of describing these strategies. In R/K selection theory, the letters R and K refer to how much an animal is able to reproduce. R stands for "R-selected species," which are animals that reproduce quickly and often, but usually don't live very long. K stands for "K-selected species," which are animals that reproduce more slowly but live longer.