Glossary of Ecology (6th ed.) by Krebs (2009)
- the movement of individuals out of an area occupied by the population, typically the site of birth or hatching.
Glossary of "Life (9th ed.)" by Sadava et al. (2011)
- The deliberate and usually oriented departure of an organism from the habitat in which it has been living.
- Krebs, C. J. 2009. Ecology, 6th ed. -xvi + 655 pp. Pearson Benjamin Cummings, San Francisco.
- Sadava, D., Hillis, D. M., Heller, H. C. & Berenbaum, M. R. 2011. Life: The Science of Biology, 9th ed. -xliv + 1266 pp. Sinauer Associates, Inc., Sunderland.