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Evolution is considered a work in progress in a constantly shifting landscape. Today, that landscape now includes cars, highways and traffic. A recent study indicates that birds may be evolving to avoid the fate of becoming roadkill.

The team of researchers were led by a man, Charles Brown, who is an amateur taxidermist. Every day, for 30 years, Brown and his colleagues have traveled down the same road to collect swallows that had been killed by traffic. The birds, which spend their winters in South America but breed in North America, live in clusters of nests on walls under bridges, overpasses and railroad tracks, according to Health Day.

Over the three decades, Brown and his colleagues discovered that there was a sharp decrease in the number of birds killed by automobiles. This decrease occurred at the same that there was an increase in the population of the swallows, Nature reports. The team compared birds who had been killed on the road with birds who has been killed accidentally by nets. They found that, while net-killed birds' wingspans had decreased over the years, birds killed by cars had longer wingspans. The researchers theorize that the larger population of birds have evolved to have shorter wingspans.

Shorter wingspans would have an immense benefit for the birds. The birds would be able to turn more rapidly, allowing them to efficiently dodge traffic. That, in turn, would give them greater opportunity to survive and pass on the gene to their offspring.

Researchers tried to account for other factors, like predators, diseases and changes in traffic patterns. They also noted that birds learn from others. Still, the fact that birds are adapting to avoid being killed by traffic is good news for other animals, like turtles and snakes, who also often find themselves the victims of motorists.

The study was published in the journal Current Biology.