While most research on language acquisition continues to consider the individual primarily in closed-system terms, Ecology of LanguageAcquisition emphasizes the emergence of linguistic development through children's and learners' interactions with their environment - spatial, social, cultural, educational, and so on - bringing to light commonalities between primary language development, child and adult second-language learning, and language acquisition by robots. Such a situated, context-responsive perspective on acquisition is able to interrelate insights from a variety of paradigms and disciplines while avoiding unjustifiable appeals to normativity. The theoretical and empirical studies presented here challenge a number of dominant ideas in language acquisition theory and mark an important new research orientati on. This work should be of interest to language acquisition researchers and professionals in a wide range of specialisms.