 This involves the use of electronic tags that emit sound in order for the researchers to track and monitor an animal within three dimensions, which is helpful in instances when large quantities of a species are being tracked at a time.Stable isotopes are one of the intrinsic markers used for studying migration of animals.One of the benefits of intrinsic markers in general, including stable isotope analysis, is that it does not require an organism to be capture and tagged and then recaptured at a later time.