NEW YORK — The next time you see birds flying in a V, consider this: A new study says they choreograph the flapping of their wings with exquisite precision to help them on their way.

That’s what scientists concluded after tracking a group of large black birds — each equipped with a tiny GPS device — that had been trained to follow an ultralight aircraft. One expert in animal flight said just gathering the data, which included every wing flap, was a remarkable accomplishment.

Scientists have long theorized that many birds like the rare northern bald ibises adopt a V formation for aerodynamic reasons.

When a bird flies, it leaves a wake. The idea is that another bird can get a boost from an updraft of air in that wake by flying behind the first bird and off to the side. When a bunch of birds use this trick, they form a V.

It’s been difficult to study this in the wild, but researchers from the University of London’s Royal Veterinary College and elsewhere met that challenge by partnering with a conservation program that is trying to reintroduce the endangered wading bird in Europe.

For about a decade, the program has hand-reared ibises from zoos and taught them their migration route by leading the way with a piloted ultralight craft. Normally, the leader of a V-formation would be a parent bird.

With the program’s help, the researchers tracked 14 juvenile ibises as they migrated between Austria and Italy.

An analysis of a seven-minute period showed that when the ibises flew in a V, they positioned themselves in just the right places to exploit the updraft in another bird’s wake, which lets them conserve their energy.