Following the monarch butterflies 2008.09.10

Written by David Green.

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By DAVID GREEN

Tagging monarch butterflies began more than 70 years ago, said Pat Hayes of the Kelley’s Island Audubon Club, but it wasn’t until the 1970s that researchers began to solve the mystery.

Eventually it became known that the monarch is the champion of the insect world when it comes to winter migration. The popular orange and black butterfly can travel more than 2,000 miles on its way to fir forests northwest of Mexico City.mon.pat.hayes.jpg

Tagging efforts have ebbed and flowed over the decades, Hayes said, and it’s currently at a strong point. Across southern Canada and throughout the United States, monarchs are caught, tagged and released with the hope that reports will be filed about their progress to Mexico.

“Prior to 1975, we had no idea where they went,” Hayes told an audience Sunday afternoon.

Hayes led a tagging project at land owned by Ed and Carol Nofziger northwest of Pettisville.

Tagging studies help researchers continue to learn about the paths taken to Mexico, the time needed to make the trip, mortality factors, population estimates, etc.

In Mexico, monarchs by the millions cluster for warmth as they pass the winter in the Sierra Madre mountains. When the temperature warms in the spring, the butterflies mate and fly back to the north.

Scientists also migrate south in search of tagged monarchs, but now much of the work is done by Mexican residents who learned they could make money helping out.mon.cage.jpg

“Peasants go looking for the monarchs and sell them for $5 each, beating out the scientists,” Hayes said.

The going rate is now $25 in some areas.

Threats

Many residents of the area continue to engage in logging of the oyamel fir tree  and acreage is shrinking dramatically.

Protected forests are watched over by armed guards, Hayes said, but they often look away when a family member comes calling with a chain saw.

It’s more than diminishing winter territory that’s threatening monarch populations.

According to organization Monarch Watch, habitat for milkweeds—the only plant used by the monarch to lay eggs—and for nectar-producing plants to nourish butterflies is disappearing at a rate of about 6,000 acres a day.

The use of genetically-modified corn and soybeans is greatly reducing milkweed populations through repeated application of glysphosate herbicides.

Frequent mowing of roadsides, along with herbicide use, also reduces the presence of milkweed.

Monarch Watch encourages “waystations” to support the butterfly population.

“They need milkweed to survive,” said Hayes, a 28-year veteran of tagging efforts. “What we’d like to see is a ribbon of fields along the way to Mexico.”

Monarchs also suffer from natural predation—attacks by birds—but birds soon learn their mistake. A poison from milkweed is taken into the developing monarch’s body when it’s in the chrysalis stage and causes the hungry bird to gag. Monarch eggs are often attacked by a parasite that causes the chrysalis to die.mon.tag.jpg

Populations tend to vary from year to year due to weather conditions and 2008 is a year of decline. Hayes collected 500 monarchs a year ago from a large shrub in his yard. This year he counted only 25. The decline has been observed in many locations around the country, he said.

If the reason is due to weather, the monarch will recover in another year. If other factors are at work, then the future of the species could be threatened.

Whatever the reason, Hayes and other like-minded friends of the monarch will do their best to ensure the butterfly has a future.

 

Learn more and follow tagged monarchs at Monarch Watch

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