Definition for K-selected species
From Biology Forums Dictionary
1) A type of life history strategy, where species have a low rate of per capita population growth but good competitive ability.
2) They are populations of a roughly constant size whose members have low reproductive rates. The offspring produced require extensive postnatal care until they have sufficiently matured. They are very limited in resourses therefore they are a very competitive species. Humans are examples of a k-selected species.
Compare with R-selected species