Texas mulberry fruit. Photo courtesy Western New Mexico University 

Our much-anticipated monsoon season has at long last arrived. With excellent early July rainfall totals in many Sky Island locations come equally strong expectations of much-needed habitat recovery. The daunting truth is that we are still officially in an “exceptional drought.” This sobering state of affairs is something that even an abundant monsoon may do little to remedy in the long term. 

Still, we can celebrate the seasonal rejuvenation of native plants and wildlife. One of my favorite plant species in monsoon season is Texas mulberry (Morus celtidifolia). This rather uncommon Sky Islands denizen not only harbors the potential of a good monsoon, but also forewarns us of the long-term effects of drought. Further, it serves as a window into the past and perhaps future of our region. 

The leaves of this species are palpably rough to the touch, so much so that it’s easy to listen to a raspy mulberry leaf symphony while rubbing one. In stature this mulberry rarely tops 25 feet tall, often with multiple, small trunks rather than a dominant central one. 

Texas mulberry ranges sporadically from the Mogollon Rim of Arizona and Gila region of New Mexico, as well as central and western Texas, into northern Mexico. While it grows most robustly along or near water sources, such as streams, rivers, and lakes, it also colonizes rocky outcrops that naturally funnel extra water to its roots. Both habitats provide insight into its drought sensitivity. Having seen hundreds of specimens of Texas mulberry over my many years in the southwest, I can attest to its mercurial nature. Good levels of precipitation engender astonishingly rapid summer growth, while drought conditions produce a rapid dieback of branches and even trunks. 

Given that most suitable habitat in Arizona only seems to support mere dozens of mulberry trees at best, a mega-drought may well spell local doom for this species. Thus, Texas mulberry may well be one our better barometers for quantifying climate change in the Sky islands. A long-term study of it and other drought-sensitive species in our region would be a worthy endeavor.

Texas mulberry uniquely flowers during the heat of May and produces fruit in June – a time when few, if any, other fruits are available to wildlife. Nor does it discriminate in proffering its abundance. Mulberry fruits are equally relished by birds and mammals alike. The cast of consuming characters includes northern mockingbirds, thrashers, bluebirds, white-nosed coatis, common gray fox, and many others. Of course, the end game for the mulberry tree is seed dispersal, which mammals and birds effect both near and far. I have devoured my fair share of mulberries over time and rate them as my favorite wild fruit. In a word they are sublime. If you are fortunate enough to beat the wildlife to a few or to hit a banner year, then you too may partake. So good are mulberries that once, having avidly picked those within easy reach, I accidentally ate four mulberry-bird-scat bundles before realizing my error! 

Historically, many (if not all) southwest native nations also ate mulberry fruit. The Havasupai of the Grand Canyon region even seem to have introduced mulberry trees to their realm in an effort to harvest its fruit. Most historic caloric gains were made via the wood of the species, however. Properly harvested and tillered, TX mulberry makes a deadly hunting bow and was often considered the premier bow wood of the region. No surprise, then, that it is related to the more famous archer’s wood, Osage orange. Many a deer or smaller game were “put upon the fire” thanks to Texas mulberry bows. The inner bark also makes a strong cordage when suitably processed. 

Ironically, one threat to our native mulberry is nonnative white mulberry from Asia. Originally introduced to New England in a failed silk industry start-up attempt, this fast-spreading species may usurp the Texas mulberries that manage to escape any climatic gauntlet. 

As drought likely will continue to cast its dark specter over our area, think back to the droughts endured by native people in centuries gone by. It was then that a Texas mulberry bow might mean death to other humans during battle. As our mulberry trees decline, I hope that their meager skeletons do not portend an analogous, contemporary death for our Sky Islands ecosystems. 

Vincent Pinto & his wife, Claudia Campos run RAVENS-WAY WILD 

JOURNEYS LLC, their Nature Adventure and Conservation organization – devoted to protecting and promoting the unique biodiversity of Sky Islands region. RWWJ offers a wide variety of private, custom-made courses including Birding and Biodiversity Tours. Visit: www.ravensnatureschool.com