Songbirds use build-in GPS to migrate across USA

the older songbirds immediately found the right course, whereas the younger birds had more trouble because they ”only” had their natural build-in compass to navigate from. But that wasn’t sensitive enough to find the way home. The young birds did have a sense of the passage, but they couldn’t adjust for the wrong course. Su they probably never reached home. However, the older birds have an almost global navigation system, which makes it possible for them to find their destination and to adjust the course on the way where needed, says Kasper Thorup.