Monarch Butterflies and Mexico


"I understand more and more how population is the problem. I was asking almost every peasant I met how many children they have. They say 'I have 8, 12, 15, 9.' These people are in their 50s. I ask how many children their children have. They say, 'Oh, senor, there are so many that we can't count them.' And most of them are getting their living from the forest. They want to get permits to log in the forest."

- Homero Aridjis, Mexico's foremost authority on Monarch butterflies

The migration predates human existence in the western hemisphere. For thousands of years, millions of Monarch butterflies from the United States and Canada east of the Rocky Mountains have flow up to 3,000 miles to overwinter in a small forest area in central Mexico.

Now, however, the last days of the Monarch may be in sight. The reason: rapid deforestation of Mexico's high-altitude Oyamel fir stands which provide the rare micro-climate necessary to prevent the butterflies from freezing, but keeps them cold enough so that their reproductive systems remain dormant until spring.

The Mexican forest wintering ground of the Monarch was not discovered by scientists until 1975. By the mid-1980s, scientists realized that rapid deforestation in the Oyamel fir forest was not sustainable, and could drive the Eastern Monarch butterfly to extinction. At that time, the Mexican government created a monarch reserve of approximately 62 square miles that consisted of no-logging zones at five known overwintering sites. But local residents have largely ignored the restrictions, saying they are too poor to care about the monarch -- the trees must fall to put food on the table for hungry mouths. "Maybe it wouldn't be such a bad thing if the butterflies didn't come back. At least we could log," said one campesino.

Ultimately, humans and butterflies are competing for the same forest resources. Unless population growth is stemmed and alternative economic opportunities are developed, the fate of the Monarch may be sealed. Aerial photographs of the region 30 years ago show a forest of nearly 2,000 square miles. Today, only a tenth of it remains. The largest tract today is 20 square miles, five times smaller than the largest tract 15 years ago

Familiy Planning Matters

Back in 1970, demographers predicted Mexico's population would rise from 50 to over 132 million by the year 2000.

The good news is that because of an aggressive family planning program, the fertility rate of Mexico has dropped from 6.1 in 1970 to 2.7 today and Mexico's population is 32 million lower than predicted 30 years ago.

The bad news is that demographic momentum is still expected to carry Mexico past the 135 million mark over the course of the next 30 years.