A Eurasian chaffinch.(iStock)Researchers once thought that when birds took breaks on long migration routes, they were stopping to build up their fat reserves for the rest of their journey.New research, however, suggests another reason: They're refreshing their immune systems.In a study published in Biology Letters, researchers found that migratory birds boost their immune systems during breaks from marathon flights.
[
add
]
[
|
|
...
]