Nancy and I visited Tucson in 2010 in part to see the Colorado Rockies baseball club play a spring training game. It was their last spring in Tucson, as they moved their training operations to Phoenix the next year. We got a rental car at the airport, and driving away from the airport and into Tucson proper, we saw a saguaro (pr.: sah-WAH-row) cactus growing by the side of the road. We were so excited that we almost stopped and took a picture of it.
We needn’t have. We saw a lot more saguaros on that trip. They’re fairly common in the Tucson area, but not as common as they used to be because of land development and agricultural practices. Protecting a forest of saguaro cactus was the impetus behind the establishment of Saguaro National Monument in 1933, and the area was elevated to a national park in 1994.
The national park is divided into two districts, Rincon Mountain on the east and Tucson Mountain on the west, with the city of Tucson in the middle. We visited the Rincon Mountain District in mid-March, and enjoyed a five-mile loop hike (with only 185 feet gain in altitude) on the Loma Verde Trail.
I think this is a fairly typical image that most people see in their minds when they think of Arizona: flat, hot, and not a lot of plants, with some mountains in the background. But there’s a lot of diversity in this photo: several different species of cacti, some grasses, and a palo verde tree on the right side. There are a lot of palo verde (Spanish for “green stick”) trees in and around Tucson. They are the state tree of Arizona, and easily live for 100 years and in some cases 400 years.
During the hike, Nancy and I saw a lot of different kinds of cacti and succulents, some nifty birds, and a group of three German tourists with whom I briefly practiced mein Deutsch. (Me: “Woher kommen sie?” They: “Deutschland.” Me: “Willkommen!” And then we went our separate ways.)
The Loma Verde (“green hill”) Trail allows hikers to walk next to the impressively tall saguaros. The cacti usually grow up to 40 feet in height, and many have eight or more arms branching from their trunks. They are found only in the Sonoran Desert of southwestern Arizona, southeastern California, and northern Mexico.Saguaros grow very slowly: just about an inch to one-and-a-half inches in the first eight years of their lives. At 70 years of age, a saguaro will be about 6 feet tall and can start producing flowers. A 15-foot-tall saguaro is probably 95 to 100 years old, and will only start producing its first arm at that age. The spiral-looking cactus on the right was germinated around 1950 or so, and the ones on the left and center were most likely germinated in the mid- to late 19th century. The tallest saguaro on record, one growing near Cave Creek, Arizona, reached 78 feet into the sky. It was felled by a windstorm in 1986; because the plants’ root systems reach only a few inches into the soil, their great weight makes them susceptible to toppling.The pleated structure of a saguaro allows it to expand during periods of heavy rainfall. Its roots may extend only three or four inches underground, but they draw in a lot of moisture: a 40-foot saguaro that’s full of rainwater can weigh 2,000 pounds, and taller and wider cacti can weigh seven tons.Among the 25 species of cactus in the national park, including saguaro, are seven species of cholla. This specimen of staghorn cholla, spanning about five feet wide, was one of the largest we saw.This is a very common type of cactus in the southwest United States: it’s a fishhook barrel cactus, named so because of its formidable curving thorns.Some cacti say “Stay away,” and others scream it loudly. This strawberry hedgehog cactus is one of the latter.This is desert globe mallow. While they can grow up to 3 feet tall, this particular one was only about 12 inches high.This flowering shrub is called fairy duster. Its blossoms are an important source of nectar for hummingbirds and butterflies.One of the features of the Loma Verde Trail is a very short spur that leads to the top of Pink Hill (where we gained most of that 185 feet in altitude). This is looking west from the top of the hill toward the Tucson Mountains, and you can see part of Tucson at the foot of the mountain range. The Tucson Mountain District of Saguaro National Park is to the right of the mountains.This is a cristate, or crested, saguaro. The scientists aren’t entirely sure what causes the growth pattern at the top, whether it’s a genetic mutation or damage caused by lightning strikes or freezing, but it’s pretty rare: only about 25 saguaros in the park, which has thousands upon thousands of them, have this fan-shaped feature.
Damage from freezing temperatures is a real threat to saguaros. A record cold snap in Tucson in 1937 caused many of the huge cacti to die a few years later. In the 1960s researchers discovered that exposure to 20 straight hours of sub-freezing temperatures can kill a saguaro. As recently as 1980 there were predictions of saguaros being extinct by the 1990s. The cacti have recovered, however: there are now plenty of healthy saguaros in the park.
Many birds make their nests in the protective height of saguaros. The holes are originally made by Gila woodpeckers or gilded flickers, and then when they leave the cavities are occupied by a number of different other birds including owls, finches, and sparrows.Hikes with unexpected surprises are always fun. This is the site of the Loma Verde Mine, a copper and gold venture in the 1880s. It had a 350-feet-deep shaft. Although the copper ore was fairly high-grade, the mine soon closed and the shaft was filled by Civilian Conservation Corps (CCC) crews in the 1930s.
I couldn’t find online why the Loma Verde Mine closed, but I do know that it’s remarkably hot in Tucson. It was in the low 80s in mid-March when we visited the national park. I’m writing this post on April 27, and Tucson recorded its first 100-degree day of 2022 yesterday.
I learned a valuable bird photography lesson while taking this photo. From an eighth-mile away, the object on the right top of this saguaro appeared to look through my telephoto lens to be another bud of cactus growth. However, I took a picture anyway in case it was a bird of some kind. The picture didn’t turn out very well because it was from 700 feet away. From about 150 yards, it still appeared to be a cactus bud, but I took another photo anyway (this one) so that I’d have a better picture of a possible bird. From about 50 yards, it was clear without looking through my telephoto lens that it was only a cactus growth so I didn’t take any more pictures of it (I already had plenty of pictures of cactus from 150 feet away). Then, at about 40 yards, the cactus growth lifted its wings and flew off to the west. It was, in fact, an American kestrel, North America’s smallest raptor and a bird that I have really, really wanted to get a good picture of for several years. This terrible photo will have to do for now.Here we see an intrepid hiker making her way past some saguaros on the Loma Verde Trail. Who knows what she’ll see around the bend of the trail? (It’ll be more saguaros.) Note the large number of bird-nest cavities in the cactus nearest the trail – it’s like a condominium building.This cactus is at least 50 feet tall and looks like it has some stories to tell. Maybe while giving you a big hug …… but you probably wouldn’t want it to. This is a closeup of the top of a three-foot-tall saguaro growing next to the trail. It’s definitely a cactus.This photo gives an idea of the number of saguaros in the park – they’re in good shape for now, but it’s only because of the establishment of the national park that we get to see them in this quantity.
As is the case with all of the national parks and monuments we’ve visited, our experience at Saguaro National Park was fantastic. We’ll likely go to Tucson again in the coming years, and we’ll definitely travel to the other district of the park where we’ll hopefully see … more saguaros!
Tales of The Goddard 