Glossary of "Ecology (6th ed.)" by Krebs (2009)
- occurs when a number of organisms of the same or different species utilize common resources that are in short supply (exploitation) or when the organisms harm one another in the process of acquiring these resources (interference).
Glossary of "Evolution (4th ed.)" by Futuyma & Kirkpatrick (2017)
- An interaction between individuals of the same species or different species whereby resources used by one are made unavailable to others.
Glossary of "Environmental Science: Earth as a Living Planet (2nd ed.)" by Botkin & Keller (1998)
- The situation that exists when different individuals, populations, or species compete for the same resource(s) and the presence of one has a detrimental effect on the other. Sheep and cows eating grass in the same field are competitors.
- Botkin, D. B. & Keller, E. A. 1998. Environmental Science: Earth as a Living Planet, 2nd ed. -xxxxii + 649 pp. John Wiley & Sons, Inc., New York.
- Krebs, C. J. 2009. Ecology, 6th ed. -xvi + 655 pp. Pearson Benjamin Cummings, San Francisco.
- Futuyma, D. J. & Kirkpatrick, M. 2017. Evolution, 4th ed. -xviii + 602 pp. Sinauer Associates, Inc., Sunderland.