Science/Tech

Why Do Monarch Butterflies Raised In Captivity Refuse To Migrate?

For lack of a better option and process, endangered species of insects and animals are often raised in captivity, which makes perfect sense. There, the animals can freely roam and grow without any dangers in an environment that was made specifically for them.

However, in what can be considered as a cautionary tale, it seems as if North America’s monarch butterflies that are raised and bred in captivity are not capable of migration, which may come as a result of either missing genes or the lack of right environmental cues.

A clear genetic shortfall, this does not bode well, especially for citizen scientists that are trying to save the iconic butterfly that’s currently endangered. The eastern North American population of the butterfly is particularly notable for its annual late-summer to autumn migration characteristic, covering thousands of miles from North America to southern Canada, finishing its route in Mexico. And it’s not just instinctual migration either, as doing so lets them escape the harsh winters of North America.

However, seeing as the butterfly’s population has decreased by more than 80 percent in the last decade, efforts to bolster their numbers are made, including hand-rearing them in captivity. The new study however, shows that this may not always be fruitful.

Losing the way

The discovery was made by a graduate student, who tested the butterflies by tethering them to a short pole. Wild-caught monarchs went south, as it should be, while commercially sourced ones tended to fly in random directions, making them terrible migrators.

To understand this phenomenon, researchers then tested the DNA of indoor-grown monarchs and compared it with those caught from the wild. Per the results, there are many differences in the genes, pinning it down the factors such as lack of environmental cues that would orient them to start flying south.

As a result, the researchers have now requested to list the species as threatened. Furthermore, the study also encourages hobbyists and school groups to source them locally, as well as raise them outdoors, as it might help counter the unwarranted genetic shortfall.

gran-canaria-171555_960_720 A monarch butterfly. Photo by Pixabay (CC0)

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