Researchers found that a monarch butterfly's wing design could determine whether or not they will successfully reach their migration destination.
Every year millions of monarchs migrate from North America to Mexico, but not all of them make it, a De Gruyter news release reported.
A research team fund that butterflies with "less-than-ideal" wing designs tend to fall behind during the migratory period.
The team looked at how wing "size, shape and color" differ between migratory monarch butterflies using an advanced computer program.
The researchers were looking for answers as to why some butterflies survived the perilous migration and others do not.
The team captured monarch butterflies that were migration through Georgia in the U.S. on their way to Mexico.
In the past, studies have looked at how wing size affects migration, but has never taken factors into account such as wing shape.
The team compared the wing structures of butterflies in early migration with those at the end of the season.
The study results show that the earlier migrants tended to have larger wings that were "more elongated." These butterflies that were captured in early migration also tended to have redder wings. The researchers believe wing redness is an indicator of flight ability.
The monarchs that migrated later in the season tended to have smaller, lighter wings. Some of these butterflies took so long to migrate that they failed to reach their destination.
"This paper provides evidence of the importance of optimal wing characteristics for migration. This trait has so far been demonstrated in connection with migratory birds, but as far the monarch butterflies are concerned, it appears to be novel. According to the authors, the earliest migrants have the highest chance of success in reaching the winter home, and these monarchs should be prioritized for scientific studies and for conservation purposes," the news release reported.
