Science finds new cause for migratory birds’ rest stops

Researchers as soon as believed that when birds took breaks on lengthy migration routes, they have been stopping to construct up their fat reserves for the rest of their journey.

New analysis, even so, suggests yet another cause: They’re refreshing their immune systems.

In a study published in Biology Letters, researchers located that migratory birds increase their immune systems in the course of breaks from marathon flights. In fall 2021, they studied prevalent redstart, chaffinch and dunnock on Helgoland, an island off the German coast along the North Sea that is a well-liked stopover for birds on the move each and every autumn.

Researchers captured, tagged and released birds on the island numerous instances a day in the course of the study. They ended up sampling the blood of 96 birds two instances each and every more than the stopovers, which ranged from an hour in some instances to a small more than two weeks.

Blood evaluation revealed that in the course of the birds’ breaks on the island, their immune systems’ potential to attack bacteria and disintegrate pathogens and possible damaging cells in the bloodstream enhanced.

Researchers say the gains weren’t connected to the birds’ fat levels. Rather, they think the immune boosts have been due to a a lot-necessary break from the strains of marathon migrations.

Migrations are “truly intense physical activity,” they create, and aside from the physical exertion expected, birds’ travels take them into new habitats and expose them to a wide variety of pathogens.

In a news release, the researchers evaluate the stopovers to pit stops at service stations — rests that refuel vehicles and refresh their drivers.

“If you see a small bird in your garden or in the park in the course of the autumn and you know that it is heading to southern Europe or Africa, it is fascinating to consider about why it is taking a break,” Arne Hegemann, a biologist at Lund University in Sweden and a co-author of the study, stated in the release. “If they do not get meals or rest, their immune systems can not recover — which is when they danger becoming ill.”