Day in Saguaro National Park surpasses day in school

SaguaroI am standing on the patio of the visitor center at the Saguaro National Park, looking upon a forest of cacti stretching toward the Red Hills and Wasson Peak to the east. If there is a single plant that, to me, says desert, it’s the iconic image of this stately, branched cactus. I came here to see and learn about the saguaro cactus. I wasn’t disappointed.

The saguaro is the keystone plant of the intricate eco-system we call the Sonora Desert, which covers more than 100,000 square miles in the American Southwest and Mexico’s western state of Sonora as far south as Guaymas on the mainland and La Paz on the Baja Peninsula. The Saguaro National Park near Tucson, Arizona, is at the extreme northern and eastern range of the cactus.

The growth — and survival — of the saguaro depends on being within a relatively narrow microclimate. Besides the composition of the soil, which provides nourishment, it requires specific temperature and humidity conditions. Frost can kill it, so it’s restricted to lower elevations and sheltering valleys, which is why I didn’t see them everywhere during my trip. Tucson’s mean elevation is 2,600 feet above sea level. By comparison, Las Cruces is more than a thousand feet higher, so the saguaro doesn’t grow here (except for those tenderly cared for by gardeners).

This cactus is the giant among Cactaceae. That’s the scientific name for the family that includes cacti. The saguaro’s scientific name is Carnegiea gigantea. The first word was given in honor of Andrew Carnegie, although I could not find out why he was so honored. The second word speaks for itself. The largest cacti in the United States, saguaros can reach heights of more than 50 feet and weigh 16,000 pounds. But getting there is a constant struggle.

Life begins as a black seed no bigger than a pinhead. It is one of nearly 40 million seeds the cactus will produce over its lifespan of 150 to 200 years. If it germinates in the shelter of a “nurse” tree — palo verde or mesquite — it will attain a height of a quarter inch during its first year of life. A very slow grower, the saguaro may be a foot tall after 15 years. It may sprout its first arms or branches after 75 years. As a centenarian, it may reach 25 feet and need another 100 years to reach its maximum height.

A collared peccary — the javelina — hangs around the visitor center. (Below) From its configuration, you can tell this is a mature saguaro. Note the white at tops of branches, where flowers will blossom in another month.
Like all living organisms, the saguaro requires water, absorbed through a shallow root system that extends in circumference three times its height. It has a corrugated, waxy skin, with pleats that expand by 25 percent of its girth to hold water. During the rainy season, it can soak up to 200 gallons, enough to sustain it for a year.

It doesn’t produce its first flowers until it is 30 years old. Then, from April until June, the creamy white blossoms open after sunset, but wilt by dawn. The spectacle repeats itself night after night for a month, during which time as many as 100 flowers bloom. While the blossoms are open, insects, nocturnal birds, bats, and other fliers seek the flower’s nectar, conveniently cross-pollinating the plant.

The resulting fruit is bright red, its pulp infused with more than 2,000 seeds. Harvester ants, birds, javelinas, coyotes, foxes, squirrels, and other rodents feast on the fruit, distributing seeds that pass through their digestive systems.

Humans have impacted the saguaro for centuries. The Tohono O’odham people (called the Papago by the Spanish) have harvested the fruit to make jam and ceremonial wine. Livestock grazing devastated some cactus forests. Seeds could not find suitable places to grow from compacted ground. Seedlings were trampled, and nurse trees killed.

Protecting critical habitat by eliminating grazing has allowed the saguaro to recover. But, the “Monarch of the Desert” continues to be threatened from invasive species and “black-market” poaching of saguaros for use in landscaping.

This was the story I learned in the national park, but there was more. I expanded my knowledge of an animal I have encountered — although rarely — in solo desert hikes around Las Cruces. That animal is the javelina, and there is a herd that hangs around the Saguaro National Park.

The javelina may looks something like a pig. It’s not. It’s a peccary, although it’s listed as an omnivorous, non-ruminant, artiodactyl mammal among the family of new-world pigs. That a hefty phrase for an animal. It means it eats plants and animals, doesn’t chew a cud, and it related to cows, sheep, and pigs. It’s about three feet long and weighs about 40 pounds. My neighbor’s dog is bigger than that.

The park ranger explained this is a herding animal not just for social interaction but for defense. He showed a picture of three javelina sharing a prickly pear cactus with a coyote, its principal predator. The javelinas were safe; there’s strength in numbers. No single coyote could overpower a group of javelinas.

He also showed us a picture of a sow with her off-spring, called a “red” — and not a piglet — because of its red hair. Females can breed year around, producing one to three reds with each pregnancy.

I also learned, if I threatened or excited a javelina, even if I hadn’t yet seen it, I’d know from its rank odor. They’re not called the skunk pig for nothing, having a scent gland that secretes a distinctive musk.

The javelina is an omnivore, dining on agave, mesquite, and prickly pear, as well as roots, tubers, and other greens. When opportunity arises, they will eat lizards, rodents, and dead birds.

I waited in the park to see its resident herd, but it was too early in the afternoon — and too hot. Like any smart desert critter — not including me — the javelina is active in early morning and at dusk. They likely hang around the visitor center because there’s an abundance of plant food and the human presence and commotion keeps wary predators at bay. Perhaps next time, I’ll get to hear them click their two-inch-long incisors together, making a distinctive sound that communicates like a wolf ’s howl and helping keep track of individuals while warning against threats. A herd all clicking together can be quite formidable.

You can hike in Saguaro National Park 24 hours a day, although the visitor center is only open from 9 a.m. until 5 p.m. daily except Christmas Day. There is a $15 individual weekly pass for one car and all its passengers.