Sci 275 - Population Size

Population Size

Axia College

SCI 275

Teacher:

Date:

Four factors for a high population rate of nutria are: suitability to the habitat, the expansive food supply, high breeding rate, and low death rate. Nutria have webbed feet which make them excellent swimmers and their sensory organs like the mouth, ears, and nose are lined up on the top of their head which allows them to be submerged under the water line. Because nutria eat almost a fourth of their total body weight a day, they eat almost anything green. Louisiana marshes are covered with green vegetation allowing them a large food supply. They can produce up to 40 offspring in three years time. Six months after birth those offspring can multiple themselves. It is normal for a male to have two or three mates which share the same burrow. The females give birth about twice a year. They usually start mating again two days after giving birth (Krause, 2005, ¶ 3). And because they were brought in from South America they have may have fewer natural predators which would keep their population in check. Current predators include alligators, cottonmouth moccasins, hawks, owls and eagles (Krause, 2005, ¶ 12). These factors cause the population of Nutria to increase exponentially over time. That is, until something falls.

The future of Nutria rests on its food supply. Favored foods for nutria include rushes, reeds, cattails, arrowhead, square-stem spike rush and sawgrass. But because of such a large population and a ravenous hunger they eat almost all vegetation causing the production of less favored foods for themselves and other wildlife species (Krause, 2005, ¶ 5). This will eventually cause the habitat in which they live to currently fail. So either the Nutria will slowly die off as the food supply shortens or they will spread out in such of other food stuffs. So either way the amount of Nutria will die down significantly along with many other species. But if they leave the current area and do find another food supply, it is possible that the process starts again. They reproduce, and deplete the land of the natural resources needed to survive. Although it is always possible they could move into an area which is unable to support them or has a predator which will keep the population down even further. Unless something significant changes, Nutria will be here to stay and will probably move to other areas to which are able to sustain them.

References:

Krause, T. (2005). National Trapper Association. In Nutria.