跨洋跨洲迁徙的物种最容易受到威胁，因为如此长的迁徙过程中充满了危险，它们因此成为能让科学家了解它们的行为的技术的受益者。
Because species that migrate across oceans and continents tend to be the most endangered, owing to the threats that such long journeys involve, they benefit from any technologies that allow scientists to learn about their behavior.