On Friday, investigators said that monarch butterflies have made a big return in their wintering grounds in Mexico, after witnessing severe declines in recent years. Scientific community and media raised awareness about declining numbers of Monarch butterflies.

This season, the region covered by the orange-and-black butterflies in the mountains west of Mexico City was over three and a half times greater in comparison to last winter. The butterflies clump so heavily in forests they are counted by the area covered by them to estimate their number.

In recent years, before recovering in 2015, the number of monarchs that migrate covering a distance of 3,400-mile from the United States and Canada fell steadily. The most recent winter was even better.

In December, the butterflies spanned over a total of 10 acres, in comparison to 2.8 acres in 2014 and recorded very low with 1.66 acres in a year before. Though the news was good, the monarchs are still facing issues, because two decades back the butterflies used to cover as much as 44 acres.

Some communities in the United States are looking forward to reintroduce milkweed, a plant important to the migration of butterflies, on nearly 1,160 square miles within a time period of five years by planting and designating pesticide-free regions.

The butterflies feed and lay their eggs on milkweed plant however it has suffered due to herbicide use and decrease of open land in the United States.

Meanwhile, in Mexico in 2014, the practice of illegal logging has more than tripled in the wintering grounds of monarch butterflies, reversing many years of steady improvements. In 2012, illegal logging fell to nearly zero.

According to authorities, the reserve's buffer area has lost over 20 acres last year because of illegal logging in an area, however they mentioned that the tree cutting was sensed and many arrests were made.

Omar Vidal, director of the World Wildlife Fund in Mexico, said, “Now more than ever, Mexico, the United States, and Canada should increase their conservation efforts to protect and restore the habitat of this butterfly along its migratory route”.