After years of worrying decline, the population of monarch butterflies soared in their winter sanctuary in Mexico. The US Fish and Wildlife Service announced that population of the orange and black butterfly grew by an estimated 255% in a reserve created for their protection in Mexico. The US, Mexican, and Canadian officials said the monarch butterflies covered 9.9 acres of forest in December 2015, up from 2.8 acres in the previous year.
Joint effort by the US, Mexico and Canada
Though researchers measure the creature’s population by the area it covers, the study estimates that there were about 140 million butterflies in the mountains of central Mexico. It clearly indicates the revival of the threatened species. But officials warned that the progress may be reversed if the efforts are not sustained.
The colorful butterflies make a long flight every year from Canada and the United States to spend winter in the forests of Mexico. After traveling nearly 2800 miles, they arrive at their nesting ground between October and November, and head back north sometime in March. Mexico has created the Monarch Butterfly Biosphere Reserve to conserve the species.
Alejandro del Mazo, the chief of Mexico’s Office for Protected Areas, said the recovery was mainly due to the joint actions of the US, Mexican and Canadian governments. The US government has initiated a Pollinator Health Task Force, which aims to increase the area to 15 acres by 2020. The number of monarch butterflies is estimated to jump to 250 million by 2020.
Why was the population of monarch butterflies declining?
That would still be a far cry from about 500 million butterflies and 45 acres of the area recorded in 1996-97. The monarch butterfly population had been declining for years due to illegal logging in Mexico. Officials have also blamed the use of pesticides in the United States and Canada, which causes a decline in milkweed that the butterflies feed.
The US Fish and Wildlife Service said the country had restored more than 100,000 hectares of fields since last year without using pesticides. It has urged people across North America to plant milkweed in order to help the butterfly thrive.