“El Niño” is periodic warming of sea-surface temperatures in the Pacific Ocean that carries sometimes drastic climatic and hence ecological implications for most of the globe. When this spike in sea temperatures is particularly high, the resultant effects upon the Earth’s various ecosystems is concordantly large as well. Hence the qualifier “super” for this year’s El Niño event. Some areas of the world, especially the southern hemisphere, will likely experience severe drought. Other regions may be deluged with floods. Many sectors, as witnessed already, will endure excessive heat. Human suffering is sure to follow such extreme weather. What, then, are the implications for our Sky Islands area?
Though scientific opinions vary, the overall, short-term predictions for southeast Arizona based upon this super El Niño is for a very active monsoon season. June saw average to above average precipitation across the borderlands region. Early and mid-July did not disappoint, with anywhere from average to well above average rainfall throughout our region. With the latter stages of monsoon seasons seemingly trending with increased rainfall, perhaps the stage is set for a truly monumental monsoon come August and September. More rain naturally equates to more biodiversity, as witnessed relatively recently in the summer of 2020, when a huge monsoon season made parts of the Sky Islands look like proxies of Costa Rica. This year, be on the lookout for some of the local species mentioned below.
Raven’s Nest Nature Sanctuary serves as a microcosm of monsoonal effects on biodiversity in our Sky Islands region at large. As I pen this article, our 42-acre preserve has received over 4.5 inches of July rain — an excellent start to the monsoon. This set plants off and running — key components to our overall species richness as they furnish food, shelter and nesting sites for area wildlife. With the deep soaking rains of July, the ground sprung to life. Within days, bare soil was transformed by a delicate patina of native vegetation. Leading the way were sprouts of the annual Palmer’s amaranth. With continued rains, these summer specialists will develop into tall plants proffering calorically rich seeds to birds and mammals alike — a vital resource to see them through leaner winter months. Sunflower weed, Bolivian cilantro and various morning glories also initiated their life cycle in July, promising nectar to butterflies and other pollinators as well as forage for deer. Given the swift response of many warm-season plants to soil moisture, some species began to flower soon after the rains began. Perhaps my favorite one, growing along south-facing canyon slopes at our preserve, is mala mujer. For those of you deficient in Spanish, this translates to “bad woman” — a clear allusion to the violently stinging hairs covering this shrubby relative of cassava. Nevertheless, the showy white flowers were heavily visited by many species of butterflies.
Some invertebrate species responded even faster to our July rains. As the first good storm hit us, dry-wood termites filled the air like a squadron of fairies in tenuous flight. Visibly absent for most of the year, they emerged from our velvet mesquite and catclaw acacia trees in a mating frenzy. At ground level, predatory velvet mites began to prowl about for, not coincidentally, the larvae of termites and ants. Female desert firetail damselflies and flame skimmer dragonflies began laying eggs in our wildlife ponds. Butterly diversity also ticked up, including a few telltale sulphur species actually swept in by a few storms. All of these and many other invertebrates are now poised to explode in numbers come August and September, setting up a feast for larger creatures.
Accordingly, a good number of Sky Island bird species time their first or second nests with summer moisture. Evolution has honed them into the plant and animal foods that form a veritable cornucopia during the monsoons. July’s storms initiated the mating songs of Botteri’s and Cassin’s sparrows — close relatives of each other that literally start to sing when they hear thunder! I also spied furtive pairs of varied buntings searching for nest sites in our dense bottomland woodlands. Meanwhile, avian predators such as our pair of gray hawks, as well as red-tailed, zone-tailed, and Cooper’s hawks, prowled the preserve, looking to mug various reptiles, mammals and birds to feed their growing young. A black phoebe — a riparian specialist likely visiting from nearby Sonoita Creek State Natural Area — also began to hawk insects around our wildlife ponds, some of which were filled with the tadpoles of various toad species.
Meanwhile, Palmer agaves truly stole the show, luring in a plethora of birds to their towering flower stalks. Hooded and Bullock’s orioles, pyrrhuloxias, Lucy’s warblers, various hummingbirds, house finches and others partook of this nectar feast. Though spring is rightly touted as a birder’s paradise in the Sky Islands, monsoon birding is also a profoundly enriching experience.
As evidenced by their many mounds and holes, various species of rodents exploded in numbers. In particular, several species of pocket mice — so named for their external, fur-lined cheek pouches that they employ as carrying devices for both food and nesting material — bred and increased as if there were no tomorrow. In a state renowned for its boom-and-bust ecological cycles, it clearly pays to ride the wave of resources while it lasts. On the heels of these mammalian tidbits, expect a spike in snakes, foxes, bobcats, ringtails and other predators.
Thus, while a super El Niño certainly can spell disaster for many parts of the world, including the ocean itself, I feel as if we should not look a gift horse in the mouth if that means a good monsoon and more biodiversity in the Sky Islands. Perhaps the lightning swift response of many of our species to this abundance can also teach us something: Carpe diem, “seize the day”!
Vincent Pinto and his wife, Claudia, run Ravens-Way Wild Journeys LLC, their Nature Adventure & Conservation organization devoted to protecting and promoting the unique biodiversity of the Sky Islands region. RWWJ offers a wide variety of private, custom-made courses, birding & biodiversity tours. Visit: www.ravensnatureschool.org.