Subscribing to the belief that if you build it, they will come (nod to “Field of Dreams”), fans of monarch butterflies want Arizonans to grow milkweed to help the insects survive migrations between southern Canada and central Mexico.
Arizona isn’t known as a major flyway for the large, black and orange, winged bug, but that perception is changing.
If observations are true that more monarchs come through the Tucson area and Southern Arizona than previously thought, then backyard gardeners can play an important role in the survival of the popular butterfly, whose population has dropped 90 percent since the 1990s.
WHY SAVE MONARCHS
The monarch is what’s called an indicator species, an animal that tells biologists something about the health of an ecosystem.
“Monarchs are sort of the flagship indicator for all pollinators,” says Gary Paul Nabhan, a nature writer and co-facilitator of Make Way for Monarchs.
If loss of monarch habitat — primarily milkweed — is affecting the butterfly population, it’s affecting others that also depend on that habitat, such as bees.
And pollinators are important, says Nabhan, because without them, many foods we eat can’t grow.
There’s also a legacy of delight that people want to preserve. Gail Morris, coordinator of the Glendale-based Southwest Monarch Study, fondly recalls catching and studying monarchs as a child in Michigan. She later learned it is the butterfly that migrates the most miles.
“I want to keep that alive for future generations,” says Morris, who will speak at Tohono Chul Park later this month about her work.
MONARCH SIGHTINGS IN ARIZONA
Tens of millions of monarchs are thought to follow two migration routes. In late fall, monarchs east of the Rocky Mountains swoop into central Mexico after a journey of as many as 3,000 miles that begins in Canada. Butterflies west of the Rockies winter along the California coast. The return migrations happen in spring.
Monarchs aren’t abundant in Arizona, but they do show up, says Morris, who also is the Arizona conservation specialist with the group Monarch Watch.
Every year about 2,500 monarchs are tagged in Arizona, she says. “It’s very heavily in the southeastern part of the state ... all the way up to Phoenix,” Morris says of butterfly sightings. That includes the Canelo Hills in Santa Cruz County, the Tucson area and in sky islands throughout southeast Arizona.
Other hot spots include Arivaca, Willcox, Sierra Vista and Hereford.
Arizona may be a spot where the eastern migration drifts before heading south.
“We used to think all of our monarchs would fly over to California,” she adds. “Through tagging we know most of our monarchs will go down to Mexico.”
The migration through Arizona includes breeding monarchs, whose offspring will complete the journey to Mexico if eggs can be laid on the species’ preferred host or larval plant, milkweed in the Asclepias family.
In an intriguing observation, a tagged monarch at the Arizona-Sonora Desert Museum may have stayed there for weeks, says Morris. That could indicate that some monarchs winter in the Tucson area instead of continuing to Mexican overwintering grounds.
Monarchs need milkweed for food and to lay eggs so that larvae can eat the plant.
Human development, including pesticide use in farming, has destroyed milkweed fields throughout the United States. Strong efforts to bring milkweed back are focused on the Midwest, where most of the loss has occurred.
Arizonans can play a part, insists Nabhan, who’s also a researcher and professor with the University of Arizona’s Southwest Studies Center.
“We’re not part of the problem, but we could be part of the solution,” he says.
He’s working on a national level to restore milkweed habitat through private and government partnerships on both sides of the Mexico-U.S. border.
At the local level, he’s growing milkweed around the orchard at his 5-acre Patagonia farm. It demonstrates what he wants farmers to do — put back milkweed fields around agricultural ones.
City folk can help out, too, says Morris.
“Gardens can act like a natural riparian area,” she adds. “Cities could well make the biggest difference.
“If you create a banquet, they will come.”
Monarch Watch has certified three Tucson-area gardens that it says serve as monarch way stations: Loews Ventana Canyon, Lew Sorensen Community Programs and a residence.
Master gardener Ginny Peterson grows milkweed in her yard, which is not one of the way stations, because she loves butterflies and other pollinators.
“It’s my main interest in gardening,” says Peterson, who is a member of the Southeast Arizona Butterfly Association.
She sees a few monarchs come through to share the milkweed with the similar-looking and more abundant queen butterfly. She admits it’s not “a yardful” of monarchs that come every year, but in any case, the milkweed is doing its job and “it’s still a lovely plant,” she says.