Zoology · Ch 11 — Organisms and Population
Population Interactions
Population Interactions
Individuals belonging to different populations rarely live in isolation; they interact constantly with one another over food, shelter, mating opportunities and other necessities of life. These interactions are classed as intraspecific, occurring among members of the same species (covering everyday livelihood processes such as feeding, territoriality, breeding and mutual protection), or interspecific, occurring between members of different species. Interspecific interactions are further sorted by their effect on each partner: neutral interactions, where two species live alongside each other without affecting one another at all; positive interactions, a form of symbiosis in which no partner is harmed and at least one — sometimes both — benefits, covering both mutualism and commensalism; and negative interactions, in which one or both partners are adversely affected, covering competition, predation and parasitism. Together these six interaction types — amensalism, mutualism, commensalism, competition, parasitism and preda …
| SN. NO. | TYPES OF INTERACTION | SPECIES 1 | SPECIES 2 | GENERAL NATURE OF INTERACTION | EXAMPLES |
|---|---|---|---|---|---|
| 1 | Amensalism | -- | 0 | The most powerful animal or large organisms inhibits the growth of other lower organisms | Cat and Rat |
| 2 | Mutualism | + | + | Interaction favorable to both and obligatory | Between crocodile and bird |
| 3 | Commensalism | + | 0 | Population 1, the commensal benefits, while 2 the host is not affected | Sucker fish on shark |
| 4 | Competition | -- | -- | Direct inhibition of each species by the other | Birds compete with squirrels for nuts and seeds. |