It has been found by the new researchers that those butterflies which are raised in captivity are at times not able to migrate, some because of the lack of required genes and others for the need of suitable environmental signs.
This genetic shortfall was discovered by a graduate student who after buying numerous of Monarch butterflies tethered them to a small pole, which is the most common method employed to check what direction an insect wants to head over. Tied wild-caught butterflies constantly headed towards south i.e. the similar direction they fly during their yearly flights from the Canada & US to Mexico. But neither the local butterflies which were raised indoors nor the commercially sourced ones did. They appeared to head towards random directions.
To find out the reason why the monarchs did not try to fly to the south, DNA was extracted from some of the butterflies by the researchers and comparison was made with the already sequenced genomes of the monarch. It was discovered that there were various differences but there was no pinning down of any specific gene. Even those with the right genes were not able to head in the right direction. Hence, it was concluded that those who were raised outdoors headed towards the south, but the ones indoor-raised could not because they were unable to catch the environmental cues which would notify them to fly south.
The butterflies in the colder climate like those in North America cannot survive the winter unless they migrate. Whereas, those who reside in the mild local conditions such as Australia, Central America, Africa, and South have stopped to migrate since they don’t have any need to move anywhere else.
Hence, the researchers say, the latest request to the government of the United States to list the species as endangered may be necessary.