A reproductive strategy where survival of a species is optimised by explosive increases in numbers of animals whenever environmental circumstances are favorable; typically seen with small animals that reach sexual maturity quickly, which reproduce just once but with many progeny, and which do not need to tend to their progeny for very long (if at all) after birth. In extreme cases (seen in many lower animals such as insects), death of the father follows impregnation and death of the mother follows parturition (or giving birth). The opposite reproductive strategy to K-selection.

Natural selection in situations that favor a high reproductive rate (r). This results in a species that survives by producing many young with minimal (or zero) individual resource investment by the parents; eggs or newborns are often abandoned. (r-selected, adj.)

A form of natural selection in which individuals are short-lived, reproduce early and have many offspring that get little care. Density-independent factors regulate these populations. 845