MigrationMigration is the movements or journeys made by animals to places outside their natural environment for an extended period of time (Dingle 2007). Typically, when migrating, animals look for a sustainable location that has plenty of necessary resources. Some animals migrate between the same areas while others avoid returning to the same area. A general rule when discussing where animals migrate is to look at the lifespan of the animal. Animals with longer lifespans tend to return to their original locations over time, while animals with shorter lifespans tend to continue to new locations over time. At least one organism within each of the five vertebrate classes has been documented as participating in migration. Later the migration of fish (especially salmon) and birds will be discussed in more depth, but first a basic knowledge of migration and what it all in the tails should appear. There are many ways to track animal migration and track them. the methods have been improved over time. American naturalist John James Audubon, in 1803, was the first recorded person to question and somehow track bird migration. He wondered whether or not a group of migratory birds that left for the winter returned in the summer. To test this, he tied a string around the leg of one of the birds in question and waited. Much to his satisfaction, the bird with the string around its leg did indeed return north for the summer. For obvious reasons, this was not considered the most accurate form of tracking, but it was a start. Another method used to track animals is called radio tracking. Radio tracking involved two elements: the transmitter and the receiver. The transmitter was...... middle of paper ...... to a decrease in the overall salmon population, which in turn can affect the fishing industry and more so the economy. ConclusionIn conclusion, not all migrations happen in the same way or are even triggered by the same things. While some migrations are triggered by genetics, others can be learned over time or may be forced to occur due to a need for resources. The resources that can fuel this movement of animals are not only food, water, and shelter, but also the need for reproductive advantages. Whether through internal compasses or biological clocks, something contributes to an individual's need for movement and survival. As the comparison of salmon and birds shows; both animals must migrate. Although the reasons for why and how are different, the overall need is still there, making it a very important aspect when studying animal movements and behaviors..