The scientists got new insights into the incredible monarch butterflies and their migration behavior after they carried sequencing of their genome.
According to the scientists, a single flight muscle related gene plays a major role in the mass migration of the monarch butterflies.
During the study, the researchers also identified the gene responsible for the striking orange-and-black coloration of these butterflies.
Marcus Kronforst, a professor of ecology and evolution at the University of Chicago who also participated in the study, said, “It’s really amazing that these little colourful creatures live for months and fly thousands of miles to perform this annual migration.”
For the study to know their migrating behavior, the researchers sequenced genomes of 92 monarch butterflies worldwide including the non-migratory ones. Nine butterflies from closely related species were also included for the study.
The researchers compared the genetic blueprint of migratory monarch butterflies with the non-migratory ones in order find out the genetic basis for their migration.
“One gene really stood out from everything else in the genome,” Kronforst underlined.
According to the researchers, a gene related to collagen which is the main ingredient in connective tissue was responsible for their flight muscle function. It was surprising to note that the gene was found less active in migratory butterflies.
North America’s mass migration of monarch butterflies, covering a long stretch of e 3,000-mile (4,800-km), is one of the fantastic feats of the insects in the world. These little creatures cover millions of kilometers during their arduous journey from as far north as Canada to Mexico or the California coast every autumn season.
“Our study shows that monarchs have been doing this every year for millions of years. There is nothing else like this on the planet,” Kronforst asserted.
According to Kronforst, an estimated one billion monarch butterflies had migrated to Mexico in the year 1996. The number now stands at about 35 million this past winter.
The most probable reasons behind the huge loss in their numbers are loss of habitat, excessive human interference, overuse of pesticides that kill milkweed, and most importantly climate change, experts say.
The monarch butterflies are mainly a North American species but their delightful population can also be seen in Central America and South America. Notably, the insects living outside North America do not migrate.
The findings of the study were published in the journal Nature.