Populations - Research Article from Macmillan Science Library: Animal Sciences

This encyclopedia article consists of approximately 7 pages of information about Populations.
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Environmental Variables

All populations are ultimately controlled by the carrying capacity of their environment. The carrying capacity is the sum of all resources needed by a specific species in order to survive. The abundance of food is a major control. When food is short, young, old, and unfit members will die.

If two or more species are competing for one food source, additional pressure is placed on both populations. If two species of birds rely heavily on a certain insect for protein and nutrition, the availability and abundance of that insect is crucial. Any reduction in the population of insects will result in a loss of species from either bird population. There may not be enough food to feed and rear the young. Older birds unable to fly long distances for alternate food will also perish.

Food is not the only limiting factor that affects carrying capacity. Shelter and...

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This section contains 1,883 words
(approx. 7 pages at 300 words per page)
Buy the Populations Encyclopedia Article
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Macmillan Science Library: Animal Sciences
Populations from Macmillan Science Library: Animal Sciences. Copyright © 2001-2006 by Macmillan Reference USA, an imprint of the Gale Group. All rights reserved.
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