BLACK MOUNTAIN’S SPECIAL PLANTS AND WILDLIFE: LESSONS IN SURVIVAL
LIVING WITH DROUGHT
The plants on Black Mountain rely on two basic strategies to survive for many months without water: water conservation and dormancy.
The leaves of the bushy creosote shrub are the secret to its survival: they have a varnish-like coating that slows down evaporation, and when times are very dry, the plants shed their leaves and don’t grow new ones until after sufficient rainfall. Rainfall has another benefit: moisture causes the creosotes to release a pungent, musky fragrance that permeates the mountain air.
The tiny leaves on the palo verde conserve water because they have very little surface area through which water can evaporate. Cacti lose no water to evaporation, because they have no leaves. Cacti are unmatchable when it comes to water gathering and water conservation. Their roots absorb large amounts of water in a short amount of time, and they store the water in their flesh.
The largest cactus in the United States thrives in Black Mountain’s desert environment. It is the saguaro, the Sonoran Desert’s signature plant and the source of Arizona’s state flower. A mature saguaro has a widespread, shallow root system that soaks as much as 200 gallons of water when it rains. As the roots drink up the rain, the saguaro fills with water and expands like an accordion. During dry spells its body deflates as it relies on the fluid inside for survival.
Plants like the triangle-leaf bursage live through drought by dropping their leaves and becoming dormant. They actually look dead, but they revive once again after it rains.
THRIVING ON INTERDEPENDENCE
Black Mountain’s ecosystem consists of a fascinating balance of plants and animals that rely on one another for sustenance and protection.
Deer, rabbits, javelinas, and even humans eat the red fruit produced by the prickly pear cactus. Called tunas, the fruit develops after the bright yellow, orange or red flowers drop from the plant’s fleshy, prickly, pear-shaped pads, which javelinas also like to munch.
The palo verde’s seed husks and pods feed wildlife, and its yellow flowers attract bees and other insects.
The saguaro’s pulp and seeds feed birds and rodents, plus ants and other insects. Scorpions create homes in fallen saguaros. Woodpeckers drill holes in live saguaros to create nests, which owls and other birds inhabit later on.
Infant saguaros might not survive without the protection of Black Mountain’s “nurse plants,” such as the palo verde, creosote and bursage, which protect tiny saguaros from the sun and from being trampled by animals and humans. It’s difficult to imagine that saguaros, which can reach a height of 50 feet or more and live for 200 years, ever need protection. But after one year of life they reach a mere 1/2 inch in height. It takes another 14 years to reach one foot in height. It takes 40 to 50 years to reach ten feet, and 75 to 100 years to reach 12 to 20 feet.
SOME INTRIGUING CURIOSITIES
Among the desert plant curiosities you’ll find on Black Mountain is the barrel cactus, which acts as a compass because it always leans to the south. Shaped like a barrel, it can grow up to 10 feet tall and live more than 300 years.
The desert plant most feared by humans is at home on Black Mountain. It’s called chain fruit cholla or jumping cholla. Its spines penetrate clothing and shoes upon the slightest contact, as though they jumped at you. Although people avoid it like the dickens, it doesn’t deter some animals from eating its fruit and making it their home. For example, cactus wrens build their nests in cholla, and white-throated wood rats (aka pack rats) use the cholla’s sharp spines to build mounds around their nests to discourage predators.
MULTI-PURPOSE PLANTS
Like the animals that live on the mountain, people also enjoy the cacti’s and trees’ edible and utilitarian qualities. The saguaro’s sweet fruit may be eaten raw or dried, boiled into syrup, and fermented into wine. Prickly pear fruit is made into jellies, dressings, syrups and candy.
People have used the ribs of dead saguaros to build shelters, fences and corrals, and to make hiking sticks and knick-knacks. (However, Arizona law forbids the removal of the dead plants.)
We can make red dye, face cream and itching powder, and even purify water with the prickly pear. Indians use parts of the creosote to make medicine and glue.
ABOUT THE ANIMALS AND INSECTS
Although you will no longer see the wolves, jaguars, ocelots, or bighorn sheep that were plentiful 100 years ago, Black Mountain still supports a diverse population of wildlife. Javelina, coyotes, bobcats, mountain lions, great horned owls, raccoons, fox, kangaroo rats, skunks, squirrels, chipmunks, gophers, black-tailed jackrabbits, desert cottontails, Harris antelope squirrels, Townsend's big-eared bats, desert mule deer, Gila monsters, rattlesnakes, roadrunners, Gambel’s quail, mourning doves, curve-billed thrasher, lizards, toads, spiders, Gila woodpeckers, roadrunners, rock wrens, cactus wrens, black-throated sparrows, cardinals, hawks, eagles, hummingbirds, mockingbirds, house finches, rodents, scorpions, tarantulas, centipedes, crickets, and the Hualapai tiger beetle still reside on the mountain.
LIVING WITH DROUGHT
Like Black Mountain’s plants, its wild creatures have adapted to the dry conditions of the Sonoran Desert. Desert toads retain water by burrowing into moist soil. To ward off the midday heat, kangaroo rats retreat to sealed underground dens, where they recycle the moisture from their own breath. Reptiles and birds retain water in their bodies by excreting a dry form of urine.
Predatory and scavenging animals like the Turkey Vulture obtain moisture from their food. Leaf-eating animals get their water from the moisture in green leaves. Birds, bats and lizards that eat insects benefit from the water that the insects consumed.
LIVING WITH HEAT
Many of the wild creatures you’ll find on Black Mountain survive the heat by sleeping in caves or underground during the day, and foraging when it’s cooler, at night. These species include rattlesnakes, Gila monsters and bats. Some desert animals avoid the heat altogether by hibernating during summer months.
Owls cool off by fluttering their throat region to evaporate water from their mouth cavities. The blood vessels in jackrabbits’ long ears release heat when the animal rests in cool locations. Vultures excrete urine on their legs to cool themselves through evaporation. They also beat the heat by soaring on thermals of cooler air. Lizards move like lightning over hot surfaces to avoid as much heat as possible as they make their way to cooler crevices.
LIVING WITH HUMANS
Even with all of their adaptive mechanisms, the number of wild creatures on Black Mountain is dwindling at an alarming rate, due to a recent growth spurt along the mountain’s lower elevations. Year after year, dozens of new homes and condominiums replace the animals’ protective brush and natural habitats. Practices that seem insignificant to people harm Black Mountain’s wildlife. Birds and snakes become trapped in the wire and nylon mesh that we use to encase our trees and gardens. Unthinking residents who use rat poison to kill pack rats indirectly kill coyotes and other animals that eat the poisoned rats. And drought is compounding our plant and creature losses.
Black Mountain’s creatures are essential to its mystique. The chuckling quail, the howling coyotes; the melodious cardinals, the snorting javelinas; the stealthy bobcats, the scurrying insects; the bouncing bunnies, the soaring eagles; the shy deer, the assertive thrashers: they all make Black Mountain pulsate with life, and they charm everyone who has the privilege to observe them.
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