Kstrategieën

K-strategieën, in ecology and evolutionary biology, describe a set of life-history traits that favor persistence near the environmental carrying capacity (K). The concept arises from the r/K selection framework, which contrasts strategies that maximize reproductive output in unstable environments (r-strategists) with those that optimize competitive success at high population density (K-strategists). The idea, developed and refined by ecologists such as MacArthur and Wilson, serves as a useful heuristic for understanding how species allocate energy to growth, reproduction, and survival.

Typical characteristics of K-strategists include relatively large body size, late maturity, long lifespans, and a low reproductive rate. They often invest heavily in offspring, providing substantial parental care or social support, and they tend to be territorial or have limited dispersal. K-strategists are adapted to stable or predictably changing environments where competition for finite resources is intense. Population sizes of K-strategists tend to hover near the carrying capacity, with fluctuations dampened by density-dependent factors rather than by explosive growth.

Examples commonly cited as K-strategists include elephants, whales, many primates, and other long-lived species that reproduce infrequently and invest substantially in each offspring. In contrast, r-strategists produce many offspring with relatively little parental care to exploit unpredictable conditions.

Criticism and modern perspective: the r/K framework is a simplification and not a strict dichotomy. Many species exhibit mixed or context-dependent strategies, and contemporary life-history theory emphasizes continua of traits and trade-offs rather than a binary classification. Environmental variability, age structure, and ecological interactions influence strategy selection in ways that extend beyond a simple r versus K label.