The Courier-Journal, January 28, 2015

Monarch butterfly numbers up in Mexico
By James Bruggers

There's some good news for monarch butterflies and their fans -- the area occupied by these iconic insects wintering in Mexico has rebounded about 70 percent from last year's record low population count, marking a significant increase in their numbers.

But conservation groups and scientists say the population that reached its wintering grounds in Mexico is still very small, by historical standards.

And that's not good.

The Associated press reports that last year, the monarchs gathering at their common wintering ground covered only 1.65 acres, the smallest area since record-keeping began in 1993. This year, the butterflies covered 2.79 acres, Mexican environmental authorities and scientists announced Tuesday.

That's a 69 percent increase.

At their peak in 1996, by comparison, the monarchs covered more than 44.5 acres in the mountains west of Mexico City.

This year's population increase was probably largely due to "good monarch breeding weather" last summer in the upper Midwest, Karen Oberhauser, a conservation biologist at the University of Minnesota, Twin Cities, told the Science magazine.

The Center for Biological Diversity, which advocates that the butterfly should be federal protected as a threatened species, said this year's tally amounts to about 56.5 million butterflies, up from 33.5 million the year before:

But the 56.5 million monarchs currently gathered in Mexico for the winter still represents a population decline of 82 percent from the 20-year average — and a decline of 95 percent from the population highs in the mid-1990s. This year's population was expected to be much larger due to nearly perfect climate conditions during the breeding season.

"The population increase is welcome news, but the monarch must reach a much larger population size to be able to bounce back from ups and downs, so this much-loved butterfly still needs Endangered Species Act protection to ensure that it's around for future generations," said Tierra Curry, a senior scientist at the center.

I covered the plight of the monarch in a front-page feature story earlier this month, noting that the U.S. Fish and Wildlife Service had agreed to study whether it should consider protection under the powerful Endangered Species Act. One of the big issues is the role of agriculture in wiping out milkweed plants, the monarch caterpillar's sole source of food:

Any eventual listing could bring more conservation of the butterfly's habitat, putting a pinch on farmers and St. Louis-based company Monsanto, whose Roundup herbicide and genetically engineered crops such as corn and soybeans were cited in the petition as a leading cause in the butterfly's decline. Herbicide tolerant varieties comprise 94 percent of soybeans and 89 percent of all corn grown in the United States, and herbicides used on them have been wiping out milkweed, the monarch caterpillar's sole food source, according to the petition.

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