Unformatted text preview: The four factors that produce changes in population size includes on a global scale, the change in population is due to the number of births and deaths. However, in the local populations, like in the United States, the number of births, deaths, immigrants, and emigrants will affect the population size. The factors that affect population size in the video include but not limited to when the importation of the animals like the Nutria (Myocastor coypus) which are actually native to South America. Brought to the Americas as a potential fur-bearer in the 1930's then in turn, as the fur market declined the overpopulation began. In addition to importation, the adult female Nutria in an average three-year span will have 30 to well over 30 babies; those babies will breed and have babies. Nutria weighs an average of 12.0 pounds (5.4 kg). Females have four pairs of mammary glands that are located on the side of the body, rather than on the belly. Presumably, this positioning of the mammary glands allows the young to body, rather than on the belly....
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- Fall '10
- Americas, population size, adult female Nutria