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Musings of a Cancer Doctor

Wide-ranging views and perspective from George W. Sledge, Jr., MD

Friday, October 9, 2020

My Backyard

By George W. Sledge, Jr., MD

The COVID-19 pandemic, and the "sheltering in place" it brought with it, has made me appreciate my backyard. It's not a large space, just a smallish rectangle bordered on two sides by stucco walls, on the third by a freestanding garage that we used as a storage area, and on the fourth by our house. I've enjoyed sitting on the back porch doing my work these past few months, but often I'm just taking in my majestic domain.

Backyards in my Palo Alto neighborhood are small. I can walk across mine in 15 or 20 seconds. It is a humble locale and will never find its way to Better Homes and Gardens, but it is the place of small miracles. Let me share some of them with you.

Surveying the Landscape

Taking a census of the denizens of my backyard doesn't take too long. I am horrible at identifying plants. I've lost most of what I learned in the Boy Scouts, or in that single semester of college botany. Nor am I an amateur landscape architect. The previous owners clearly set store by their ability to populate the backyard with interesting flora, but much is wasted on me.

I do see two small palms, which I am unable to identify with online resources. There are a few pines, quite lovely in their own way, and what looks to be a young willow. But the plant I appreciate the most is a sage bush with lovely pink and white flowers. I've looked through books trying to decide what species this is. One online resource said that there are 89 different species of sage in California. I looked at their pictures trying to decide which is mine, but nothing I saw looked quite right.

I love the sage because it is beloved by honeybees and hummingbirds. I'll be outside early in the morning and suddenly a hummingbird will dart in, place its beak in a sage flower, then another, then dart away again.

I'm fascinated by these small creatures. They weigh less than an ounce, insubstantial little beauties. They are, I have read, the only bird that can fly both forwards and backwards. Sometimes one will hover a few feet away from me for a few seconds, eyeing me as I look at it, then zip off. Hummingbird facts seem like fake news: their wings beat up to 80 times a second, and their hearts 1,200 times a minute when in flight. To maintain such a high metabolism (the highest of any non-insect animal) they eat prodigiously, and love plant nectar, though they also cleanse my backyard of mosquitoes and gnats. They may eat half their body weight in nectar every day. They are small miracles.

Hummingbirds are limited to North and South America. The ones in my backyard appear to be Anna's hummingbirds, the most common species in California. The males are quite beautiful, a mix of iridescent green on the body and reddish pink around the head and throat. The females are less flashy, mostly gray-colored, though for some reason it is the females that always look me over the most when I'm watering the plants.

Anna's hummingbirds, in case you are interested, are named after Anne D'Essling, a courtier in the court of Empress Eugenie, the wife of Napoleon III of France. Anne is described as having been "pretty and refined in appearance, with an exceedingly lofty manner, though small in stature," which could be a pretty good description of her eponymous hummingbird. Why were my hummingbirds named after her? She was friends with René Primevère Lesson, the ornithologist who first described the species. It's good to be friends with scientists: they name things after you.

None of this matters, of course, other than in a Trivial Pursuit sort of way, but that's sheltering in place during a pandemic for you.

I love the hummingbirds, for their beauty and acrobatic grace. But I respect the California scrub jays (Aphelocoma californica) that patrol my backyard. These birds have a mixed reputation. They are—how shall I put this—thugs and thieves. They attack hummingbirds and eat baby birds of other species. For that matter, they are quite willing to attack people if riled up enough. Gangs of scrub jays will even murder their own, pecking them to death in grisly territorial displays. One recent local newspaper article called them "bullying," "harassing," and "the most hated birds in the Bay area." They steal food from other animals. Their bird calls are not mellifluous. The calls—no one would ever call them songs—have been described as, variously, a scratchy weep, a harsh scold, a guttural growl, and (when alarmed) a rapid, mechanical "hiccup" sound. You cannot confuse a scrub jay for a lark.

So not loveable, indeed downright obnoxious, but a species I respect. They are quite brilliant members of the genius Corvid family (along with crows, ravens, and magpies), arguably the most intelligent of birds. There is an extensive scientific literature devoted to the California scrub jay. Though not large—they weigh in at just over 3 ounces—their brain-to-body mass ratio is the equal of chimps and whales, and only surpassed by humans.

I mentioned that they steal, and the food they steal they cache for later eating. They may hide food in as many as 200 places. Here's what's fascinating: they not only remember where they have cached food, they remember what they have cached. If they cache a worm or a grub—limited shelf life—they will come back and eat it before it spoils. But give them a peanut (they love peanuts) and they will store it for the long haul. As my wife pointed out to me, that makes them smarter than a lot of people we know with stinky refrigerators. And because scrub jays are total paranoids, they will frequently move their caches. They will watch other birds store food and steal from their caches. They have prodigious memories for human faces, even years later. They appear to be one of the few species that plans for the future.

They also appear to mourn their dead. Maybe mourning is not the right word, but jays appear to understand death, at some level. If a California scrub jay comes upon a dead member of its species, it will call other jays, who will perch over the dead jay, screeching for up to half an hour. Then, for the next day or two, they will avoid the area. I haven't seen jays sitting shiva myself, but it is extensively well-documented. Anyways, they are smart, and intelligence deserves respect, even if they are not beautiful like hummingbirds. Or so my inner nerd says.

Tending the Garden

Moving on. We harvest some small amounts of food from my backyard. We have a lovely and productive lemon tree that never seems to give up, balanced by a small, miserable tangerine tree that has never really gotten going.

As I'm writing this, it is summer, so we're raising tomatoes. I carefully water them every other day. We only planted five this year, mostly cherry tomato varietals. They love the hot, sunny California summer but are greedy for water, so I visit them regularly with a garden hose. Last week it poured rain for 2 hours or so, the first rain in months, and it allowed me some respite from watering them. The cherry tomatoes taste like candy—I pick them off the vine and pop them straight into my mouth.

I said we planted five tomato plants, but now there are only three. I came out in the morning to water the plants, and one had been pulled up by its roots, leaving only a few shredded leaves behind. And then, a few days later, another disappeared, chewed off at the base. I don't think it was a jay, and I know it wasn't me. The only other identifiable culprits large enough that I can identify are the neighbor's cats and the squirrels.

The squirrels are black, and like the scrub jays they are polarizing figures. Black squirrels, some think, fall into the "so ugly they are cute" category, but for others they are just rats with furry tails. I'm partial to them, even if one actually is the culprit in the great tomato heist. There is a wonderfully persistent urban legend attached to them, suggesting that they are the result of an experiment gone wrong in some Stanford genetics laboratory, released by mistake into the wild. Totally untrue, of course: the black squirrel is just a melanistic subgroup of the more common gray squirrels, the result of a 24-base pair deletion from their melanocortin 1 receptor gene, if you want to get all sciency about it. And CRISPR-Cas9 technology is too new to be blamed for their genetic engineering.

I'm at best a mediocre gardener. I can water tomatoes and do some minor weeding, but that is the extent of my accomplishments. When the weeds overgrow the backyard, we bring in some handymen who spend several hours pulling them out and mulching them, and filling bags for later disposal. Which reminds me of my clinic.

Oncologists are fond of analogies. We use them to turn complex concepts into something with a more human scale, something bite-sized and at least a little comprehensible. Antibody-drug conjugates become smart bombs, cell surface receptors are catchers' mitts for baseball-ligands, and immune checkpoints and their inhibitors call to mind having your foot off and on car brakes. The list could go on and on. We all have our favorites.

A common one involves the yard. Imagine, I tell my patients, a lovely green yard. Now imagine crabgrass proliferating and taking over that yard. Sometimes you pull the crabgrass out if there's a small localized patch. Let's call that surgery. Sometimes the lawn needs a good coating of herbicide: that's systemic chemotherapy for microscopic metastases.

But the analogies aren't that good in my backyard. When I lived in the verdant Midwest with its plentiful rain and lush green lawns, I could easily visualize that crabgrass analogy. All I had to do was step out my front door. Here in the Bay Area, where it's dry 9 months of the year and drought is the default mode to such an extent that we have an actual fire season, I have no grass in my backyard, hence no crabgrass.

But I do have weeds. After our brief wet season, the backyard looking unruly and unloved, we had the gardeners come and de-weed. Through no fault of their own—we under-instructed or under-supervised—they pulled out too much. Some lovely California poppies disappeared as did some fragrant mints. Our iris plants were in full bloom, and obviously ornamental, so they survived. But the overall effect was to create sterile, brown-looking soil unencumbered with vegetation. Almost like, well, life after high-dose chemo in the bone marrow, or some such.

That weedy yard metaphor had metastasized to my own backyard, now revised to include the toxicity of therapy. Analogies are tricky things.

I'm hoping that next spring the green will return, and the pretty orange poppies and the fragrant mints. I'll even take the weeds. What is a weed after all but a plant that is out of place? Cancer cells are not just milk ducts growing in the lung or colonic epithelium in the liver. They're abnormal, not just out of place. The weeds in my backyard arguably are not even that: just normal California flora that doesn't quite look right.

Let me finish with a patch of lichen near my back porch. This is a gray-green amorphous thing hugging a rock for dear life. I have read that lichen cover 7 percent of the land surface, but my backyard is certainly dragging that average down. I doubt it amounts to a square foot of coverage. But this is another small miracle. Try and live off of the nutrients provided by a rock and see how long you last. I've seen it there for years, never really changing. And that gives me comfort.

Lichen are a mixture of fungi with either cyanobacteria or algae or both, living in synergistic harmony. They are old creatures, having existed for 250 million years. It was thought, until recently, that they preceded plants onto dry land, but that apparently is not the case. They latch on to all sorts of surfaces, happily breaking them down: soil, tree bark, dead animals. And in my backyard, on a rock.

How do you eat a rock? The lichen's fungal filaments penetrate small cracks in the rock, excreting oxalic acids (of kidney stone fame) that dissolve minerals and chelate metals locked in stone. Over time—a very long time—they break down the rock. These small wonders work patiently on a seemingly impossible, Sisyphean task and will do so long after I'm gone. The world goes on, and we barely know it or record it. There's something wonderful in that.