Entering June, southern Arizona lives up to its infamous reputation as a veritable furnace, with daytime temperatures frequently breaching the 100-degree mark at lower elevations, creating uncomfortable conditions for humans and other species alike. The old adage “at least it’s a dry heat” seems a cruel joke, as we all bake in the oven-like conditions of fore-summer.
Keep in mind, however, that the same heat that drives us to distraction now also serves to lure in monsoon moisture. We might then say “cool June, no monsoon!” The National Oceanic and Atmospheric Administration has forecast a good possibility of an average to above average monsoon this year. If that vague prediction proves true, then get ready for the cavalcade of species that emerge early in the monsoon. Even isolated June precipitation can bring forth various flora, fauna and fungi that are reliant upon wet conditions and high levels of humidity—monsoon specialists, one and all, to varying degrees.
Among our rain-dependent species is the Sonoran tiger salamander—Arizona’s only species of salamander. This endangered subspecies, confined to far-eastern Santa Cruz and adjoining far western Cochise Counties, is heavily reliant upon vernal pools formed during the monsoon. No pools, no breeding. Remnant populations survive in and near the San Rafael Valley, even extending up into the higher reaches of both the Huachuca and Patagonia Mountains.
Fungi can be lightning-swift in their monsoonal response. Witness inky cap mushrooms, including Coprinus atramentarius. This species of club fungi seems to come out overnight, soon forming parasol-shaped tops that bear the reproductive spores. This species lives up to its billing, the top dissolving into a liquid, black goo that was once used to make both writing and culinary ink. Mmm, mmm good!
Some plants also rush out of the starting gates thanks to early monsoon storms. Two of my favorites at Raven’s Nest Nature Sanctuary are trailing windmills in the four-o’clock family and silverleaf morning glory in its namesake family. Both are warm-season perennials that poke out when moisture soaks their roots. The windmills are a deep magenta, recalling bougainvilleas, which are also in the same family of plants. The morning glories are small, but attractively sky-blue affairs—they’re outliers of most morning glories, which prefer conditions later in summer. Each of these two native wildflowers tends to hug the ground where humidity levels are higher and drying breezes more attenuated.
All manner of invertebrates are essentially monsoon specialists. Paper wasps in the genus Polistes are so tied to moisture that I often use them as examples of species that can lead desperate souls to water in a wilderness survival situation. Have you ever noticed one of these dangly-legged, painfully stinging wasps flying perilously close to your sunglasses or other shiny paraphernalia? They are not out to sting you, they’re simply trying to slake their thirst. Mind you, if you see a number of wasps approaching your face, then run like @#%&!!
Pulling the graveyard shift among insects are several species of bombardier beetles. In a world rife with misleading names—witness “silk” flowers made from synthetic materials—these beetles are aptly dubbed. They are able to produce a chemical explosion in their abdomen that reaches 100 degrees C. This proves no small deterrent to would-be predators. The pyrotechnics produce a puff of smoke, created with an audible pop which discolors human skin if you are foolish enough to touch one.
The onslaught of monsoon invertebrates proves a tasty boon for white-backed hog-nosed skunks, one of four skunk species in the Madrean Archipelago. Employing their extremely long claws they often root around in soil and decaying wood, searching for beetle larvae and other toothsome treats. In drier times, they can dig up rodents, lizards and other fossorial fare to make ends meet.
Among our reptiles, the endangered Mexican garter snake persists in some riparian areas. They have been ravaged by introduced and rapacious bullfrogs, placing their future in great jeopardy. Monsoon storms can help these small snakes to recolonize otherwise dry stretches of streams and rivers as each expands with ample rains.
We end with a bird so synonymous with precipitation that it bears the confusing name “rain crow.” In the Sky Islands, western yellow-billed cuckoos migrate back from their winter haunts in June—the latest-arriving neotropical migrant in our area. This endangered relative of our greater roadrunner sets up shop in riparian areas in order to breed. Come late August or September, they head south to warmer, wetter climes.
In a world dealing with catastrophic climate change, only time will tell what will happen to our monsoons. Will they become more erratic? Might they swell in force, threatening floods and local destruction? What if they dry up altogether? At this juncture, all possibilities seem on the table. One thing is for sure: I truly treasure all of the monsoon specialists—they are testaments to resiliency that none of us should take for granted.