Monarch butterflies in decline; genetically engineered crops blamed
As many as 50 people could attend the monarch
butterfly tagging event in Moraine State Park in Portersville,
Pennsylvania. Yet the group will be lucky if it tags a single one, park
officials say.
"They are just not around the
way they used to be. I have probably only seen five this year, and I
look for them all the time. Years ago, there were so many more," said
Stephanie Taylor, an educator at the park.
The population of monarch butterflies has
declined 90 percent in the past two decades, according to the Center for
Biological Diversity, an environmental group that blames the decline on
herbicides and the planting of genetically engineered crops in the
Midwest, where monarchs once thrived. The butterfly is a pollinator,
though not as important as honeybees, whose numbers are falling sharply
as well.
Last month, the biodiversity center,
the Center for Food Safety, the Xerces Society — another environmental
group — and monarch scientist Lincoln Brower petitioned the federal Fish
and Wildlife Service to declare monarch butterflies an endangered
species.
The groups say the butterfly's population has fallen from a high of 1 billion in the mid-1990s to about 35 million last year.
"Monarchs
are in a deadly free fall, and the threats they face are now so large
in scale that Endangered Species Act protection is needed sooner rather
than later, while there is still time to reverse the severe decline in
the heart of their range," said Brower, a professor at Sweet Briar
College in Virginia who has studied the monarch for 60 years.
It's
estimated that the orange and black butterflies may have lost more than
165 million acres of habitat, an area the size of Texas, including
nearly a third of their summer breeding grounds.
In
the space of a month, monarchs lay eggs on milkweed leaves that hatch
into caterpillars, morph into chrysalises and transform into
butterflies.
The butterfly's dramatic decline
is being driven by widespread planting of genetically engineered crops
in the Midwest, where most monarchs are born, according to the petition
filed with the federal government.
Among the
most easily recognizable of butterflies in North America, a single
monarch can travel thousands of miles from Canada to the same spot in
Central Mexico every winter.
"It's such an
unusual and magnificent migration," said June Bernard of Hampton, an
educator at the Pittsburgh Zoo who raises and tags monarchs.
"I
have not seen as many this year. I have friends and have talked to
people who said they have not seen them either," said Bernard, whose
first recovered tagged Monarch flew 1,872 miles to Mexico in 2003.
Bernard has tagged 125 monarchs this year.
Not everyone is a proponent of classifying monarchs as endangered.
"That
could take 10 years. We want to concentrate on restoration, which can
be done now," said Chip Taylor, a professor of ecology and evolutionary
biology at the University of Kansas and the founder of Monarch Watch.
Genetically
modified crops and the corn ethanol mandate have all but eliminated
milkweed, the monarch caterpillar's only food, in many farming areas,
Taylor said.
Most genetically engineered crops
are resistant to Monsanto's Roundup herbicide, which the petition says
kills milkweed. Requiring corn ethanol in gasoline has resulted in fewer
acres of uncultivated land for milkweed.
A
Monsanto spokeswoman said the issue is that farmers have to limit weeds,
such as milkweed, to grow crops. The company is working with experts to
establish more habitats for monarchs outside farmland, spokeswoman
Charla Lord said in an email.
Without
milkweeds, monarchs are not able to produce successive generations that
result in the yearly fall migration. Without nectar from flowers, the
monarchs are unable to make their long journey to Mexico.
"It's symbolic of a bigger problem. Many pollinators are in decline," Taylor said.
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