THESE BIRDS ARE RACING TO THEIR MATING GROUNDS. IT’S EXHAUSTING.

Geese have a problem. Some are arriving at their Arctic mating grounds so exhausted they’re not in the mood anymore.

Shifting environmental signals caused by global warming are making the birds race northward on their spring migration, flying faster and skipping the stops they normally use to rest and refuel, according to a study published recently in the journal Current Biology.

Scientists said the finding was important because it gives new insight into the way climate change is altering the calculus of

animal migration.

“This is the first one I know of where a long distance migrant is increasing its travel speed,” said Matthew P. Ayres, a professor of biology at Dartmouth College who was not involved in this study.

The birds in the study, barnacle geese, spend their summers in the Arctic, where warmer temperatures transform the snowy landscape into an all-you-can-eat buffet of grasses, roots and mosses.

Their migration is triggered by changes in daylight. As days grow longer in spring, the geese take sunlight as a cue to head north. The goal is to arrive early enough in the spring to take advantage of the tender spring greens that are especially beneficial for chicks.

But as human-caused climate change shifts weather patterns, spring arrives earlier in the Arctic some years. The birds don’t know that. And, critically, they don’t know that they should get an early start.

Once the birds are en route, environmental cues like lots of make them realize that spring has arrived early in the north. The barnacle geese change their behavior, increasing airspeed and skipping the avian rest stops that they ordinarily use to fuel their travel and to fatten themselves up for the egg-laying ahead.

The geese take the time to rebuild their strength when they arrive, but that means nesting is delayed.

As a result, their chicks are born when the food supply is past its prime. They “hatch while the vegetation is already not optimal, and they grow less and they survive less,” said Bart Nolet, a professor at the Netherlands Institute of Ecology and an author of the study.

The Arctic is warming faster than any other region on Earth, and eventually spring may come much, much earlier. Farther ahead of schedule than birds have ever dealt with.