A study published Wednesday in the journal Nature reveals surprising new insights into the genetics of the monarch butterfly, well known around the world for its distinctive black and orange wings and annual mass migration across North America.

Researchers of the study, led by Marcus Kronforst of the University of Chicago, sequenced and compared the genomes of 101 butterflies from around the globe, including migratory North American monarchs, non-migratory monarchs, and a few closely related species. The study uncovered a number of details about the monarch butterfly, Danaus plexippus, such as history of evolutionary origin, genetic basis of warning coloration, and the genes and pathways involved with migratory behavior.

Researchers discovered that migratory butterflies expressed reduced levels of collagen IV a-1, which is a gene involved in flight muscle formation. “Migration is regarded as a complex behavior, but every time that the butterflies have lost migration, they change in exactly the same way, in this one gene involved in flight muscle efficiency,” said Kronforst in a recent statement. “In populations that have lost migration, efficiency goes down, suggesting there is a benefit to flying fast and hard when they don’t need to migrate.”

According to the statement, more research needs to be done to fully understand the butterfly’s evolutionary history. “In order to clearly resolve the history of monarch butterflies, we still need additional fossil, archaeological and genetic data, as well as more advanced technology, becoming available in the future,” said co-author Shuai Zhan of the Shanghai Institutes for Biological Sciences.

Researchers of the study also highlight the need for conservation efforts to preserve the migration patterns of the monarch butterfly. One possible reason for the recent decline in monarch migration is the loss of milkweed, the butterfly’s primary habitat, due to agricultural herbicide use. “You used to see huge numbers of monarchs, clouds of them passing by,” said Kronforst. “Now it looks quite possible that in the not too distant future, this annual migration won’t happen.”