From Hawks to Hawk-Moths

At some point during my decades of watching and researching hawks in the Marin Headlands, I began to notice insects. At first it was butterflies: migrating monarchs, local pipe-vine swallowtails, hilltopping West Coast ladies, and red admirals. Then dragonflies. A handful of odonate species were Hawk Hill regulars, but on some October afternoons, the sky seemed to explode with variegated meadowhawks, hundreds in one binocular sweep.

I was hooked. I adjusted my long-distance raptor-spotting and started looking for flying things much closer and much smaller. And I got curious. How many insect species pass through the Headlands? Could they be counted like raptors? Did they have a peak flight season or day? What species were common, which were endangered? It felt like I was starting all over again, moving into the novice seat, the excitement of being a raw student.

As I learned to see invertebrates, bee ecologist Sara Leon Guerrero offered me a piece of advice: Insect identification is different from bird identification. You cannot identify many insects to the species level. Taking an insect to the genus or family level may be the best you can do.

In summer 2023, I got grabbed by moths. I had spent a July day in the Sierra Nevada with lepidopterists Paul Johnson and Megan Gnekow, who lead annual butterfly counts across California. At day’s end, Paul mentioned that he’d be setting up a moth sheet at their campsite.  

“What’s a moth sheet?” I had no idea. 

“Just tack up a white cotton sheet. Point a black light at it a little before sunset. Leave it all up for a few hours and take photos of what lands on it.”

And so I did just that, first in the Tahoe National Forest, where on my inaugural night I photographed 20 moths from 16 species, some with crazy beautiful wing patterns and even crazier names: wandering tiger, impressive dagger, shadowy arches. By August, I was back in Berkeley, and I wondered: Would a moth sheet work here? Deep down, I expected nothing. How many moth species could live in the urban Bay Area?  

During the last two weeks of August, I tacked a moth sheet to the wall of my small Berkeley porch each night. I pointed a 10-watt UV black light at it and checked for moths every half hour or so. Moths are drawn to lights, but UV light is especially seductive to some moth species, even 50 meters away. Dozens of scientific articles have been written on the still-mysterious moth-light relationship. Big-city lights have even been cited as a possible cause of the enormous loss of insect abundance.

Each time a new moth settled on the sheet, I stalked it with camera phone and flashlight and took the closest photo I could manage. The flashlight was clunky, so I soon traded up for a doughnut-shaped clip-light that attached directly to the phone—an essential tool for moth nerds. On most nights, only a few moths showed up, but during 14 days I racked up more than 50 moths, each a startling species (or genus) new to me, often with a wonderful name—obelisk dart, pink-margined green, sage plume, lunate zale, four-spotted yellowneck, and volupial mint moth among them.

Now, 30 months into nightly “moth-lighting” in Berkeley at the end of 2025, I’ve photographed 5,000 moths of 239 kinds and have been stunned by the diversity of species, colors, patterns, and forms. Speaking only as a neophyte moth-watcher, the Bay Area has many beautiful and compelling moths.

Though I’ve only paid serious attention to moths for the last four years, there’s a much older moth story that has propelled me. In the summer of 1971, when I was 9, my mom brought my brothers and me to see our grandmother for a monthly visit. Gran lived in a tucked-away house in an oak forest in the South Bay hills. I remember that specific day because she announced that she had something special to show us.