"Somewhere, something incredible is waiting to be known." — Carl Sagan 

By DR. CAMERON BARROWS

My love affair with California deserts and their sky island mountains began the moment I arrived here in December 1985. I had grown up in coastal southern California, but spent no time in our deserts, accepting the conventional wisdom that they were just a hot, dry, wastelands.

Growing up I found myself increasingly repulsed with the obsessive, rampant conversion of open space into stucco homes and manicured lawns, beginning on the coast in the 1950s, 1960s and 1970s, on any relatively flat land west of the Peninsular and Transverse Mountain ranges. When I turned 18 years old, I escaped north, spending a couple years at Humbolt State University (recently unnecessarily re-christened “Cal Poly Humboldt University”) in the far northwestern corner of the state, and finally settling (for a while) at the University of California Davis.

It was there I had my eyes opened to the scientific discipline called natural history. It was also where I met my life-long partner, Katie, in a class called the “Natural History of the Sacramento Valley” taught by David Gaines. David later successfully spearheaded the protection of Mono Lake, a body of water on the east side of the Sierra Nevada that was being wrung dry by the Los Angeles water authorities in their insatiable drive to secure (steal) water so that southern California could continue to support its housing growth and manicured lawns. David showed us how we could do good science and be an advocate for the protection of nature. The class, like any good natural history course, was mostly field trips. One of those field trips brought us to a Coast Redwood Forest in the California Coast Range. David instilled excitement with every bird, lizard, bug, and plant we discovered, but there in the redwoods he was especially thrilled with a sighting of a spotted owl, Strix occidentalis. He explained that it was an exceptionally rare sighting and that nothing was known about them.

My major at Davis was “Conservation of Natural Resources,” while Katie’s was “Wildlife Biology.” While my major allowed me to take and receive graduation credits for any class remotely related to the study of wildlife and plants, Katie’s was much more rigorous and prescribed. Her major also required a senior project. She could have done her senior project on a month-long summer retreat at Honey Lake in the Great Basin Desert east of the Sierra Nevada Mountains, or come up with her own independent study. We remembered that spotted owl sighting and opted to learn something about a species that was otherwise unknown. It also meant spending the summer together, so an easy choice.

What little that was then known about spotted owls could have fit on a single page of our field notebooks. When found, they showed no interest, fear or otherwise, in humans. Earlier naturalists, whose objectives were to collect museum specimens, admonished others from wasting a bullet on a spotted owl as they could easily be caught by hand. That, and they appeared to be restricted to old growth, never-been-logged forests filled with centuries-old conifers and hardwoods. That observation caught the attention of the logging industry, which began to caution that any restrictions on their activity would doom the source of lumber feeding the housing boom and put thousands of their workers out of work. The reality was that those old growth forests were a finite, irreplaceable resource and such forests that were not already in State or National Parks were quickly disappearing whether or not anyone cared about spotted owls. Sawmills were already re-tooling to focus on cutting smaller second and third growth trees. Serendipitously, the industry also disseminated tongue-in-cheek “how to cook and eat a spotted owl” recipes. That was the backdrop for our first summer with spotted owls. David helped us find a study site, a forest in Mendocino County near the coastal town of Fort Bragg. The forest was co-owned and jointly managed by a private non-profit organization, The Nature Conservancy, along with the federal Bureau of Land Management. It was called the Northern California Coast Range Preserve, and at 8,000 acres it was the largest unlogged watershed left in northwestern California. David said that there were spotted owls there.

Our accommodations on the Preserve were meager at best. A single room cabin built in the early 1900s that we shared with a woodrat and several bats, and that would have fallen over if we leaned on any of its walls. We could also count stars through its porous roof. The cabin may have had a colorful past, built and occupied by a single woman, “Fanny”, who may or may have not entertained gentlemen there during the 1920s and 1930s, visitors from a guest lodge a quarter of a mile further down the road. The only furniture inside was a wrought iron, double-wide bed with a bare spring “mattress.”

Job one was to find spotted owls. The only available method was to walk through the forest at night imitating their contact call, whooo – who – who – whoooooo. It turned out Katie was much better at eliciting responses. Still, over those 8,000 acres we only found two breeding pairs of owls. After locating the owls at night, we would return in the morning looking for where the owls roosted during the day. With thousands of trees to search, it was seemingly like finding the proverbial needle in a haystack, yet it worked. The key was to look down, not up in the trees. Looking up would invariably mean tripping over thickets of ferns and huckleberry bushes and countless tree roots. Looking down meant much fewer bruised knees and the owls would leave their numerous calling cards on the ground in the form of bright white feces and gray regurgitated pellets of rodent hair and bones. Once we started seeing those calling cards, we could then look up to see if the owls were home. After some time, we also developed a gestalt for what sort of tree the owls would typically roost in. In this forest it was typically in tan oaks, Lithocarpus densiflorus, (so named because their bark was harvested and used to tan animal hides) and then only in tan oaks with the densest canopies. With that search image we could look at a stand of trees and spot the most likely candidate for an owl roost – and be right more often than not. The early naturalists were right about the owls not being terribly interested in humans. Typically, they would fall asleep within just a few minutes of us walking up and peering at them from below – sometimes within arm’s reach of where we stood.

We collected and dissected hundreds of those regurgitated pellets. Favorite foods in this region were flying squirrels, woodrats, and tree voles, a species of mouse that spends its entire life high in an old-growth Douglas fir tree, eating only the tree’s needles. Each of those rodents, but especially the flying squirrels and tree voles, was closely tied to old growth forests. During days and days watching sleeping owls, we also began to notice that on warm days, when temperatures approached 85 degrees and warmer, the owls began panting, using a behavior called gular fluttering, to evaporate water from inside their throat and therefore cool their entire body. Even though they were experiencing heat stress at what seemed to be relatively cool temperatures, we found that their roosts were by far the coolest locations across the entire forest. The big conifers captured most of the solar heat high in their canopies and then the dense canopies of the oaks added another layer of solar protection. Had they roosted anywhere else their stress levels would have been much higher, perhaps too high to survive. It wasn’t that the owls had a particular affection for big trees and unlogged forests, it was because they needed those forests to stay cool and find their preferred foods. At sites with cooler overall climates, either closer to the ocean or higher in the mountains, these owls can be found in forests lacking those giant, centuries-old conifers.

Katie and I published those initial findings, the first ever for California, in 1978, the same year we got married. In 1980, I earned a Master’s Degree by continuing that spotted owl research in the Southern California mountains where we found the same patterns. The result was a handful of research papers published that pulled back the mysteries as to how and why spotted owls do what they do and where.  With that Master’s Degree in hand, when the job of managing that same Northern California Coast Range Preserve opened up, Katie and I applied, and were selected as a team to manage those same owls and enormous redwoods and Douglas firs. Five years later, Colin was born, and our future was soon to change. The Nature Conservancy opted to transfer the Preserve to the University of California as a research station, just like the local Boyd Deep Canyon Desert Research Station in Palm Desert and the James Reserve up near Idyllwild. The Nature Conservancy offered the reins of the newly created Coachella Valley Preserve, and my love affair with deserts and lizards began.

Part of that affection for deserts and lizards is the contrast with the challenges presented when conducting research in a complex multi-layered forest on species that requires territories from over 600 to over 14,000 acres (depending on habitat quality) for each pair to survive. After that first year at the Northern California Coast Range Preserve (now called the Angelo Preserve), we had a pretty good idea of where we could find two pairs of spotted owls, but that was hardly an impressive sample size. After another five years we had a pretty good idea about what factors were associated with those same two pairs that would breed in some years, but often take a year or two or more off from making reproductive attempts. Successful breeding was linked with higher numbers of large flying squirrels and woodrats in their diet, whereas in non-breeding years the much smaller tree voles dominated their diets. Again, hardly a robust sample size. We couldn’t answer whether the owls made a decision to breed and then sought those larger prey, or were the larger prey especially abundant in some years and because of that abundance the owls opted to breed (for unknown reasons – flying squirrels eat mushrooms, while woodrats eat acorns, conifer seeds, and fruits)? Cause and effect were difficult to untangle.

In deserts, studying lizards, large sample sizes are easier to collect. Rather than a handful of individuals, we can look at population level responses to environmental change. That change is largely mediated by the onset, amount, and timing of rainfall, which then dictates the species and densities of annual wildflowers, which then dictates insect abundance, which then dictates the reproductive success of the lizards. With warmer temperatures and longer droughts, higher rainfall levels shift to higher elevations, and plants, insects, and lizards should shift as well. Cause and effect relationships are clear, and the confidence with the science is far better.

Nullius in verba                                                                                                             

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