Competition is an interaction between organisms or species in which the fitness of one is lowered by the presence of another. According to evolutionary theory, this competition within and between species for resources plays a role in natural selection.
Two species in competition often continue long-term in the same environment. This suggests they each have an "edge" which the other does not. In may cases being there first is a big edge. For example, plants consume nitrogen by absorbing it into their roots, making nitrogen unavailable to nearby plants.
Species in competition may directly interfere with each other. An example of this can be seen between the ant Novomessor cockerelli and red harvester ants, where the first interferes with the ability of the second to forage. It does this by plugging the entrances to their rival's colonies with small rocks.
- Pocheville, Arnaud 2015. The ecological niche: history and recent controversies. In Heams, Thomas; Huneman, Philippe; Lecointre, Guillaume; (eds) Handbook of Evolutionary Thinking in the Sciences. Dordrecht: Springer. pp. 547–586. ISBN 978-94-017-9014-7
- Barton, Kasey E.; Sanders, Nathan J.; Gordon, Deborah M. (2002). "The effects of proximity and colony age on interspecific interference competition between the desert ants Pogonomyrmex barbatus and Aphaenogaster cockerelli". American Midland Naturalist. 148 (2): 376–382. doi:10.1674/0003-0031(2002)148[0376:TEOPAC]2.0.CO;2. S2CID 7668877.
- Gordon, Deborah M. (February 1988). "Nest-plugging: interference competition in desert ants (Novomessor cockerelli and Pogonomyrmex barbatus)". Oecologia. 75 (1): 114–118. Bibcode:1988Oecol..75..114G. doi:10.1007/bf00378823. ISSN 0029-8549. PMID 28311843. S2CID 18989762.