But still, there is the anxiety that we have so much to do, look forward to, or even dread in some cases. We have to take the fans down, take out the woolens from the closets, and start up the heaters in our homes. Some of us even prepare for the next season by getting out our shovels from the storage shed to get ready for the big snowstorm that will occur in winter. All of these questions are fascinating to many biologists, including neurobiologists. Animals, such as birds, marine mammals, salamanders, fish, and even certain species of insects, rely on numerous environmental cues as well as internal cues in order to be able to know which way to migrate.
Migratory birds use a combination of methods to navigate.
There has been much evidence that magnetic fields play an important role in navigation. A study done by Wolfgang Wiltschko showed that when European robins were exposed to an altered magnetic field in a laboratory, the birds oriented themselves to the artificial field. The scientists concluded that the earth's magnetic field serves as a primary guidance source for navigation. Research suggests that cells in the bird's brain contain magnetite, an iron oxide crystal that aligns with magnetic north similar to a compass needle. Scientists suggest that these cells may serve as receptors that send directional information to the brain.