monarch butterfly on purple mistflower
A Monarch butterfly on purple mistflower. Credit: Courtesy / Lee Marlowe

An uncertain climate awaits monarch butterflies as they head south for their annual migration this fall. Hurricanes, wildfires, and unpredictable weather will test their resilience. And on the conservation front, the U.S. Fish and Wildlife Service must rule by Dec. 15 whether the orange-and-black insects will be listed as “threatened” under the Endangered Species Act.

Local butterfly followers have been spotting the butterflies in small numbers around San Antonio following the rains of recent weeks.

“I’ve noticed quite a few in our newest pollinator garden in the River Walk South Channel next to the flood gate by Nueva St. on the east side,” said Juan Guerra, senior horticulturist for the City of San Antonio.

Laura Jarvis, events coordinator and butterfly steward at Rainbow Gardens nursery, said for the second year in a row she’s seeing “very few” monarchs. “We usually have lots in our home waystation starting in middle September,” she said.

Peak migration for San Antonio’s latitude occurs from Oct. 10 to Oct. 22. While monarch butterfly sightings should increase in Texas over the coming weeks, monarch scientists anticipate the 2020 migration to be smaller than usual.

Karen Oberhauser, director of the University of Wisconsin-Madison Arboretum and a longtime monarch butterfly expert, said data collected via the Monarch Larvae Monitoring Project, a citizen science initiative that monitors monarchs’ breeding behavior, indicates “we’re sending slightly fewer monarchs your way than we did last year.”

Chip Taylor, founder of Monarch Watch, a monarch butterfly conservation organization based at the University of Kansas at Lawrence that tracks migrating monarchs by tagging them in the fall, also speculated that this year’s population would be small.

“Not a big migration, much lower than the last several years,” he said.

“The weather’s been a factor,” said Taylor, adding that news of recent rains in the San Antonio area after a dry summer are “a good thing.”

A dramatic drop in butterfly numbers, from a high of 1 billion in 1996 to an estimated 33 million in 2013, precipitated the potential Endangered Species Act listing.

Industrial agriculture, habitat loss, genetically modified crops, wildfires, hurricanes, and incidents of aerial pesticide spraying like this one that occurred in Fargo, North Dakota and resulted in a “monarch massacre,” have combined to take their toll on the species.

In 2014, the monarch butterfly was submitted for consideration as “threatened” under the Endangered Species Act. The U.S. Fish and Wildlife Service (USFWS) found such a listing might be warranted and initiated a status review of the species. But the agency failed to rule on the petition by the statutory 12-month deadline, and in July 2016, a Washington, D.C., court gave it three more years. In June 2019, USFWS delayed the decision another 18 months. Now a decision must be rendered by Dec.15.

Today, the eastern migratory monarch butterfly population numbers about 60 million, according to the most recent estimates. The California monarch population totaled 4.5 million in the 1980s. Last year, they numbered an estimated 29,000

“The western monarch population is in dire trouble, with less than 1 percent of the population remaining compared to the 1980s,” said Emma Pelton, a senior conservation biologist at the Xerces Society, one of several parties seeking to have the monarch protected under the Endangered Species Act. She added that some scientists believe the California population may be nearing extinction.

The potential listing inspires mixed feelings among those dedicated to the species’ study and protection.

If the USFWS lists the monarch as “threatened,” the agency could impose restrictions on handling the species, which could severely limit community science efforts like caterpillar monitoring and monarch tagging, said Wendy Caldwell, director of Monarch Joint Venture, a conservation group.

“We will not know what these restrictions are – or are not – until the decision is made,” said Caldwell.

“In my experience, especially on something like this, states and organizations can go after a broadly focused permit for a region or area that can authorize those who go through a training to tag monarch,” said Beryl Armstrong, a partner in Austin-based Plateau Land and Wildlife Management who has worked with private landowners on conservation of rare and endangered species for decades.

Armstrong and others believe the fate of the monarchs’ Endangered Species Act listing depends on who wins the presidential race.

“Just knowing what the politics are, the likelihood will depend entirely on the outcome of the election,” he said.

David Wolfe, a 30-year veteran of conservation biology and director of conservation strategy at the Environmental Defense Fund, agreed. “If Biden is elected, I think there’s a better than 50 percent chance the monarch will be listed and less than 50 percent chance if Trump is re-elected,” he said.

San Antonio Report co-founder Monika Maeckle writes about pollinators, native plants, and the ecosystems that sustain them at the Texas Butterfly Ranch website. She is also the founder and director of...