For the migrating monarch butterflies, there is no place quite like the Lone Star State
Millions of tiny visitors from the north are starting to flutter into Texas, ready to treat the state as an all-you-can-eat buffet, building up fat levels that sustain them all winter in the cool mountains of Mexico.
And if all goes well, they’ll flutter back to Texas in the spring to finish one final task — a few frantic moments of romance creating the next generation of monarchs.
For the migrating monarch butterflies, there is no place quite like the Lone Star State.
“Texas has more milkweed types than any other state, including the green antelope horn milkweed, which is probably the second most important plant in the country for these butterflies. It’s the plant most of the eggs are laid on to produce the new generation of monarchs,” said Dr. Orley R. “Chip” Taylor, founder and director of Monarch Watch at the University of Kansas.
Though monarchs are very particular about that — caterpillars won’t eat anything but milkweed — adults will sip nectar from just about any flowering plant they find, Taylor said.
So among the sights at the State Fair of Texas, you might find swarms of butterflies gorging on frostweed and other flowering plants.
“Frostweed blooms right when they come through,” said John Watts, entomologist at the Texas Discovery Gardens in Fair Park. “It’s almost like the two have evolved together, with the plants blooming when the monarchs arrive.”
The butterflies seem to like Mexican sunflowers as well — a bright orange version of the usual yellow and a great source of nectar for the butterflies.
More and more monarchs are showing up each day, said Watts, who ventures into the gardens every morning and afternoon to tag them.
“They aren’t happy when I catch them,” he said, “but the tags we use are pretty small — smaller than your pinkie fingernail — and they’re made of a thinner paper so they don’t have much weight.”
The exodus of butterflies picks up as the weather cools, experts say, and they need a good cold front with a north wind to help push them south. When that happens, high-rise dwellers in downtown Dallas can watch them sail past 20 stories up, Taylor said.
“We get emails from people who watch the monarchs flying by their windows,” he said. “They love to connect like that.”
Joanne Pospisil of Carrollton watches the monarchs from ground level — her yard is a monarch way station, with plenty of treats for the traveling butterflies. And each fall, she’s on the lookout for that first flash of orange and black.
“It’s very exciting — it’s almost magical,” she said. “It makes you feel more connected with the spirit world or something. They’re the only insect that migrates both ways like that, and we’re so lucky to live on the migration trail.
“There are a lot of people who might never see a monarch in their lifetime.”
The monarchs that funnel through Texas over the next week or two are bound for a few mountain peaks in Mexico they’ve never seen. Many, Taylor said, are four generations removed from the last batch of butterflies to make the trip. How they accomplish it remains a mystery.
“The whole migration pattern is not fully resolved,” said Taylor, a professor in the department of ecology and evolutionary biology at KU. “There are still lots of issues that have to be worked out.”
And butterflies aren’t really designed for long flights against contrary winds.
So cold fronts that drop down over the Plains are critical.
“Let’s say the monarchs have 140 milligrams of fat to begin with,” said Elizabeth Howard, director of Journey North, an Internet-based program focused on wildlife migration. “They could soar for 1,000 hours on that amount of fat. But if they have to flap, they might only go for 40 hours. That’s how efficient it is for them to soar and glide.”
And with the right wind, monarchs can travel more than 200 miles in a day.
Still, the journey to Mexico from their summer homes can take about two months, Taylor said — far longer than the typical monarch’s life cycle.
And when the temperature begins to warm in early spring, the monarchs fly north to Texas and Oklahoma, mate, lay their eggs and die, she said. Their offspring will continue the trip north.
Twenty years ago, a billion or more monarchs from east of the Continental Divide might make the journey to the mountains. But loss of habitat and year-to-year weather variations reduced the eastern population to anywhere from 30 million to 60 million in recent years.
“This year, conditions have been better for the population,” Taylor said. “It could be the best year in four or five years.”
But monarchs still face a difficult future.
Perhaps the biggest issue is loss of habitat, particularly milkweed. With farmers putting more land into production, powerful herbicides have wiped out native milkweed plants through much of the Midwest.
The National Fish and Wildlife Foundation recently approved 22 projects, including three in Texas, to plant milkweed and restore habitat, Taylor said. And he’s working with American Indian tribes in Oklahoma to restore milkweed habitats on tribal lands, and with Texas officials and the Texas Native Plant Society to plant milkweed along highways, ranchland “and all sorts of marginal landscapes.”
