photo: learner.org
Monarch butterflies are some of the most mysterious and beautiful insects on earth. It took scientists nearly a century to discover where they went to winter after a migration that takes them on a 3000 mile journey.
They go to winter and gather in a small microclimate habitat in a Mexican forest, the oyamel fir forest, a habitat that is endangered even as laws have been passed to protect it from illegal logging.
Last year marked the third straight year in which significant declines in population have been recorded. This sudden decrease is worrisome and has scientists scrambling to find out why the butterflies are dying.
Experts are agreed that today's population represents only 1/15 of the total butterfly population that existed before 1997.
The causes for such a rapid and persistent decline are cause for disagreement however. Some think that logging of the natural habitat is a cause, although lately it has been greatly reduced by protection efforts and legislation.
Others blame pesticides and climate change. But many suspect that herbicides are the primary culprit since it kills its preferred food source, milkweed.
Because the habitats of the Monarch butterfly span many countries and even more regions, the effort to save them must be shared by all the countries that the butterflies migrate to.
Mexico has done its part. Now Canada and the US must step up efforts to safeguard the insect.
The destruction of milkweed from herbicides in the United States and other regions where the butterfly migrate to, must be addressed, because the plant is also where they lay their eggs, and for the hatchlings to feed and mature.
Other causes of disruption in the life cycle of the Monarch are eccessive cold, lack of water or tree cover in Mexico. If the microclimate they winter in has a cold spell, a large number of the insect can die in one winter season.
Source: Al Jazerra 3.14.13
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