“Modern man’s difficulties, dangerous beliefs and feelings ... are caused by his illusions about, and separation from, the natural world” — Benjamin Hoff

One positive outcome of the necessary isolation, keeping myself and all those I care about safe and healthy during this pandemic, is that I have been able to gain a deeper appreciation of my backyard. Our home looks out upon the Santa Rosa Mountains, the northern extent of the Peninsular Mountain Range, mountains that reach their northern terminus here, otherwise extending south, forming the backbone of the Baja California peninsula. My home office looks out upon an arguably tiny backyard, a space that I have populated with plants native to “Baja." As I talk on Zoom, dabble on an art project, type reports, analyze data, and try to construct intelligible descriptions of those data for (hopeful) publications, I look out upon this small desert oasis and watch the comings and goings of birds, lizards, and insects, and how they interact with these plants.

Lizards, side-blotched and desert spiny lizards, emerge onto rock piles as the temperatures become just right. The rock piles give the lizards a chance against their primary predator here, the greater roadrunner, who makes daily visits to see if any of the lizards are not being sufficiently vigilant. The smaller side-blotched lizards emerge first as that smaller size (greater surface-to-volume-ratio) allows them to warm faster, and then later in the day the larger desert spiny lizards appear. The birds have a clear preference for one plant, Palo Adan (Adam’s tree), Fouquieria diguetii. Named after Léon Diguet, a French chemical engineer turned naturalist, who, while working for a French mining company in Baja California during the late 19^th Century, collected many plant species previously undescribed and named by western science. He sent his specimens back to museums in France where they were often christened with Léon’s last name.

Palo Adan is one of 11 species of plants in the genus Fouquieria, all of which are restricted to the deserts of North America and is one of three which are endemic to the Baja Peninsula. Only one of these 11 are native to the deserts of the U.S., F. splendens, the ocotillo. Ocotillo can be found in the Chihuahua, Sonora, and Colorado Deserts. They along with all Fouquieria, are superbly adapted to desert life by being drought deciduous — they drop their leaves every time it gets too dry to support them. Leaves are where plants usually maintain their food production factories that pull in carbon dioxide and convert it to sugars for the plant to use as chemical building blocks for all their growth and reproduction. The CO₂ enters the plant through pores in the leaves and those same pores emit the waste product of these sugar factories, water vapor.  Losing water in a region where water is in short supply is not conducive to the longevity of a plant, so they have evolved adaptations to limit water loss: no leaves (i.e. cacti), small waxy leaves to limit water loss (i.e. creosote bushes), or they are drought deciduous. Ocotillo are often used as accent plants in desert landscaping, but property owners are often frustrated that the ocotillo look like they are dead, no leaves or flowers for so much of the year, or for years on end, even when being irrigated. The problem is that ocotillo are fussy about how much water they receive, too little or too much and they shut down. They do not like daily irrigation any more than they like drought. The “Goldilocks” level is to keep them dry for a month or two and then soak them for a day or two. Healthy ocotillo will then leaf out and flower for a month or two before once again dropping their leaves. You can repeat this cycle as much as three times a year.

Palo Adan are different. First, unlike the typically straight, up-right canes of an ocotillo, Palo Adan canes are branching and spreading in many directions. For that reason, rather than an accent plant, they are better used as a focal element in desert landscaping. Another difference is that Palo Adan, at least the one in my backyard, bloom every day, all year long. Hence their popularity with birds and insects. Their flowers, like ocotillos, are bright red and tubular — clearly an advertisement to be pollenated by hummingbirds. The Costa’s hummingbirds in my yard love them. I never need to set out hummingbird feeders, the Palo Adan take care of that for me; there are typically three to six hummingbirds calling my yard home all year round. Other birds are attracted as well, mainly to the abundant insect pollinators that are also attracted to the year-round blooms. I almost never water my plant, although I suspect its roots might be trespassing under the wall and gaining access to my neighbor’s daily watering. 

In my Palo Adan this spring, during the northward migration of birds, I observed Nashville, Townsend’s, Wilson’s, and Orange-crowned warblers daily. There were also western tanagers, black-headed grosbeaks, hooded orioles, and one lazuli bunting. I have a lot of plants in my yard, but the birds were always in the Palo Adan. There were also year-round residents, including mockingbirds, house finches, and verdins. 

Verdins are diminutive, endearing birds, the only western hemisphere member of a family of birds, Remizidae. Verdins, exclusively found here in our deserts, have a yellow head, chestnut-colored epaulets, and are otherwise gray colored. Verdins construct spherical nests with an entrance-exit tunnel near the bottom of the softball-sized sphere. Such a nest protects the verdins from the weather extremes in deserts, apparently such an important function that verdins sleep in them all year long, regardless of whether they are nesting or not. When they are nesting and rearing young, these spheres of sticks probably serve to protect their hatchlings from predators, at least most of the time.

In preparation for nesting, this year the verdins built their nest in the Palo Adan. Given that it was such a busy tree, with the comings and goings of birds all day long, I questioned their choice, but they did not listen to me. Most birds nest in hidden locations, away from the eyes of potential nest marauders. I watched the verdins bring sticks in and expertly fit them into place, and the sphere quickly took shape. When ready, the verdins copulated on a branch immediately outside their nest entrance, again and again. Then the female would once a day disappear into the nest where I assumed she was laying her egg and then emerge sometime later. Eventually she spent more time in the nest which I interpreted as the beginning of incubation. A couple of days later I watched as house sparrows, tore open the top for the nest sphere and consumed the verdin’s eggs. House sparrows are European birds introduced to North America by human immigrants who thought they would cleverly bring with them each of the bird species mentioned in William Shakespeare’s plays and sonnets. Starlings and house sparrows were the two species that survived and spread across North America. The verdins disappeared for two weeks. I hoped they might regroup and nest elsewhere, and perhaps they did. Then the verdins returned and sat on that same branch were the consummated their bond so many times before, but this time, in front of the tattered remains of their nest, they emitted a mournful, prolonged chatter like none I had ever heard before. 

Of course, I have no way of knowing for certain what the verdins were communicating. However, it caused me to think of how we humans try so hard to elevate ourselves as separate and above the other species we share this planet with. “It's just a cow, a lizard, or a chicken, or a verdin” and so could not have the same sense of loss, of a future and a past. In her book, “The Genius of Birds," Jennifer Ackerman showed us how birds can be problem solvers and tool users at levels far in excess of human children (and probably some adults). Every time we draw a line and say “that’s what makes humans above other animals,” we then find some animal capable of crossing that line. Instead of looking for those differences, it is far easier to identify what joins us together, and perhaps by not discounting those other species, their ability to have responses that would be similar to ours if or situations were reversed, we would then better stewards of this planet.

Nullius in verba

Go outside, tip your hat to a chuckwalla (and a cactus), and be safe.