The monarch butterfly appears to be experiencing a massive population crash, the likes of which hasn't been seen before. The butterflies, which migrate to Mexico in the fall, have been appearing there in shockingly low numbers. Last year there were 60 million, a record low that that seems enormous compared with the fewer than three million that have shown up so far this year.
From the New York Times:
“There’s no question that the loss of habitat is huge,” said Douglas Tallamy, a professor of entomology at the University of Delaware, who has long warned of the perils of disappearing insects. “We notice the monarch and bees because they are iconic insects,” he said. “But what do you think is happening to everything else?”
Monarch habitat loss has accelerated in recent years due to the proliferation of corn and soybean fields in the Midwest, which have popped up in response to federal ethanol subsidies. The converted land includes millions of acres of land once reserved in a federal conservation program. Milkweed, on which monarchs lay their eggs, is removed from these row crops. Meanwhile, difficult weather conditions for the past two years have further limited monarch reproduction rates.
What is there to be done? In a nutshell, we need to reverse the loss of habitat to give the monarchs a chance to recover.
"The really good thing about monarch butterflies is they have a very robust reproductive capacity and that means if conditions are favorable they can recover very fast," says Chip Taylor, the head of the citizen-scientist group Monarch Watch. "The conditions can't be like this forever and they will turn around, we will see favorable conditions for reproduction sometime in the future. The question is whern."
Illustration by Micah Lidberg (via NYTimes)