Mexico City – As many as 200 million monarch butterflies may migrate to Mexico this year – nearly nine times the number in 2004, when unfavorable weather, pollution and deforestation caused a drastic decline in the population, environmental officials said Tuesday.
Last year, fewer than 23 million butterflies survived long enough to leave habitats in the United States and Canada for sanctuaries in the state of Mexico, which borders Mexico City, and neighboring Michoacan state. That was at least 75 percent lower than expected but should usher in a monarch resurgence this year, officials said.
“In the past, very low numbers have recuperated and produced surprisingly high populations,” Jose Bernal, director of inspection for Mexico’s environmental-protection agency, said after a news conference to kick off Mexico’s monarch butterfly season.
After especially cold weather reduced the butterfly population to 28 million during the 2000-01 migration, the number of monarchs grew to 93 million the following year, he said.
No one knows for sure how many butterflies make the annual migration south, but Bernal said 2005 estimates will be aided by a new counting system that better determines the tens of thousands of butterflies on each acre of territory.
The monarchs’ annual 3,400- mile journey from the forests of eastern Canada and parts of the U.S. to the central Mexican mountains is an aesthetic and scientific wonder. The butterflies began reaching Mexico last week and usually continue to stream south until early December.
