Young urban newcomers snapping up apartments around the Pearl and the San Antonio Museum Reach are not the only recent arrivals to call downtown San Antonio home. Monarch butterflies, the storied insects who migrate from the mountains of Michoacan, Mexico through Texas to Canada and back each year are taking up permanent residence here, too.

Monarch butterflies are taking up residence at the San Antonio Museum Reach
Monarch butterflies are taking up residence at the San Antonio Museum Reach

The much-studied butterfly is famous for moving through San Antonio and the “Texas Funnel” en masse in late March and mid October on its annual migration.   But now, a triangular 1200-square-foot milkweed garden planted in 2009 by the San Antonio River Authority (SARA) as part of their $72 million Museum Reach renovation has resulted in an apparent year-round local colony.

Located between Schiller and Quincy streets just a five-minute walk south of the vibrant Pearl Brewery, the “Milkweed Patch” hosts about 60 Asclepias curassavica, or Tropical Milkweed plants, host to the Monarch butterfly.   Milkweed species, excellent nectar magnets for all types of butterflies, are the only plants on which the orange-and-black butterflies will lay their eggs, and thus reproduce.

Milkweed Patch on the San Antonio River Museum Reach
Park at the Pearl and Walk five minutes or at the deadend of  Myrtle near Quincy Streets to access the Milkweed Patch;  the Patch is on the west side of the River

On February 11, the Monarch Larvae Monitoring Project (MLMP), a citizen scientist program based at the University of Minnesota, added the Museum Reach Milkweed Patch to it roster of 15 sites monitored by citizen scientists in Texas. Because of its protected situation on an urban riverbank, The Milkweed Patch holds the distinction as the first Texas site to be monitored in 2012.  Most other Texas locations don’t have milkweed or Monarchs yet.

“Its historic,” says Mary Kennedy of Boerne, explaining that local Monarch butterfly communities are common along the Gulf Coast, Louisiana and Florida, but have been unheard of in San Antonio–until now.   Climate change and the advantageous conditions of a protected, well-kept milkweed garden get credit for attracting the creatures that have captivated observers for millennia.  Aztecs and other indigenous peoples associated Monarchs’ annual return to Michoacan with yearly visits by the spirits of their ancestors.  The butterfly is an icon of early November’s Day of the Dead celebrations.

Mary Kennedy, Monarch Larvae Monitoring Project
Mary Kennedy, Monarch Larvae Monitoring Project

“This is not a place they would normally be this time of year,” says Kennedy, a retired teacher who used Monarch butterflies in her science classroom at  the Texas Military Institute.  Kennedy has been monitoring Monarch butterflies for MLMP for a decade at Mitchell Lake and Cibolo Nature Center, where milkweed typically dies back during the winter.   She will lead volunteers on a monitoring effort each Saturday at 10 AM at the Milkweed Patch.

“A man-made canal bank garden, along a popular walkway, with an exotic milkweed species planted by a city government in an urban area….I’m sure you’ll be unique! ” says Dr. Karen Oberhauser, a renown butterfly biologist from the University of Minnesota and founder of the Monarch Larvae Monitoring Project.

Texas holds strategic interest to those who study Monarch butterflies, since the flying insects must pass through the Lone Star State on their migratory journey to and from Mexico.  The Milkweed Patch already has a set of scientist fans. Just in the past two months, three separate graduate students have visited the site for dissertation research.

Kelly Nail, from the University of Minnesota, is exploring the impact of climate change on the Monarch butterfly migration.  Dara Satterfield, a PhD candidate at the University of Georgia, is researching Monarch butterfly parasites.  And San Antonio’s Terry Matiella of UTSA is doing her dissertation on how climate change effects chemical levels of milkweed.

UTSA Graduate Student Terri Matiella is researching chemical properties of milkweed
UTSA Graduate Student Terri Matiella is researching chemical properties of milkweed

With its high profile location on the much trafficked San Antonio River, the Museum Reach may be one of the nation’s most easy-access urban settings in which to see Monarch butterflies in all their stages.

“We have known that numerous species were coming back to the Museum and Mission reaches since their restoration, but not about this butterfly colony in particular,” says Sara Gruber of the San Antonio Convention and Visitors Bureau (CAVB).

As Monarch butterflies start to stream through San Antonio in the coming weeks and increase the Monarch butterfly volume at the Milkweed Patch, the CAVB might consider promoting the natural attraction.  A recent Wednesday afternoon yielded a dreamy stroll embellished by Monarchs and other butterflies flitting on purple lantana and milkweeds.   Even a few caterpillars were spotted, noshing on milkweed leaves, fueling up for their chrysalis conversion.

As one pair of Monarchs locked into a courtship flight, we couldn’t help but wonder if the Milkweed Patch should be added to the CAVB’s list of Top 10 Most Romantic Spots in San Antonio.

Still curious about Monarchs and the Monarch Larvae Monitoring Project?  Check out the slideshow of Milkweed Patch monitoring at the Texas Butterfly Ranch.

Story and photos by Monika Maeckle;  Map by Google

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...