Commensalism

Commensalism is when one organism benefits, but the other is unaffected. An example is cattle and birds. When cattle graze, they stir up insects, which makes it easier for birds to eat them. The cattle is unaffected, but it provides a beneficial relationship for the birds.

In the next video, you will an example of commensalism and mutualism. Certain small fish like to travel with sharks because the sharks provide them with cover from predators looking to make a meal of the fish. Also, one type of small fish eats the parasites off the sharks - this provides the fish with food and the sharks get rid of the parasites - both species benefit from this mutualistic relationship!



Sources: http://nre509.wikidot.com/lecture-14-notes and Teachers' Domain, Unlikely Travel Companions, published November 18, 2008, retrieved on July 15, 2010, http://www.teachersdomain.org/resource/nat08.living.eco.ecos.travcom/