Arthur Shapiro at one of his butterfly monitoring sites in Central California.
Arthur Shapiro at one of his butterfly monitoring sites in Central California.

Q&A: He knows why climate change is affecting butterfly orgies

Arthur Shapiro, 75, turned a childhood fascination with butterflies into his life’s work. Nearing 50 years as a professor of evolution and ecology at UC Davis, Shapiro, who has a  Ph.D. in entomology (the study of insects), has traveled extensively in search of butterflies. One of his favorite tracking grounds is in South America, where he initiated a long-term project in the Andes and Patagonia in the late ’70s. Much closer to home, he began monitoring butterfly populations in Central California in 1972. Ever since,  Shapiro has been visiting a transect of 10 sites — from the Delta to the Sierra Nevada — on a biweekly basis. It is the longest continually running butterfly monitoring project in the world.


J.: Why butterflies?

Arthur Shapiro: I am a classic one-trick pony. I’ve been on butterflies since I was 10 or 11. I grew up in Philly, an only child. My parents had an unhappy marriage. I tried to be home as little as possible. I became addicted to being alone in the woods — we lived in the last row of houses nearby. My fifth-grade teacher engaged me with turtles and snakes. By junior high I moved to butterflies.

The Western monarch butterfly count at the Pacific Grove Monarch Sanctuary was way up this October, by more than 2,500 compared with last year. Also, breeding monarchs were found on the Google campus in Mountain View and in Palo Alto gardens, where milkweed is plentiful. What do you make of this?

Their numbers were down dramatically in the ’90s. During the five-year drought starting in 2012, their numbers went up again. The last three years have been the worst ever recorded in California, but you need a comprehensive review of what’s going on.

For many, many years, the annual cycle of butterflies was quite predictable. Historically the monarchs fly to the immediate coast for winter. They shut down on trees, and in late January and February they begin to wake up from dormancy. In February, there is a mass orgy and they fly to inland breeding grounds.

They get environmental cues — from length of daylight cycle and temperature — telling them when to shut down for breeding and when to migrate. Things have gotten more confusing for them.

How so?

Over a decade ago, some monarchs began breeding all winter long. They are not going into sexual dormancy. Monarchs are breeding in places where they didn’t used to breed at times they didn’t used to breed. We’re only getting a handle on what this means. Temperature increase due to climate change is screwing up the pattern of warming. There’s a conflict between information [butterflies get] on daylight and information on temperature.

Monarch butterfly (Photo/Wikimedia-Kenneth Dwain Harrelson CC BY-SA 3.0)
Monarch butterfly (Photo/Wikimedia-Kenneth Dwain Harrelson CC BY-SA 3.0)

Can people do anything to help? Plant milkweed for butterflies to eat and to lay their eggs on?

There’s no milkweed shortage. There’s plenty of milkweed. There is a shortage of female butterflies to lay eggs. I think a lot is going to depend on the course of climate variability. My answer is for politicians to take climate change seriously.

Do you have a favorite butterfly?

In a 50-year career, you get to know a lot of species. My favorite is the Mariposa plateada, an iridescent silver butterfly. It’s the national insect of Chile, but is more common in Argentine Patagonia. I was the first person to rear it from the egg. I used to practically commute to Argentina. I know a larger percentage of the country of Argentina than the U.S.

Do you work with enthusiasts around the world?

There’s a network of collaborators, including one in Israel: Dubi Benyamini, president of the Israeli Lepidopterists Society. He’s retired, one of the most accomplished amateur lepidopterists in the world. Dubi has been able to collect in places where you’d think an Israeli would never be able to go, like the Cedar Mountains in Lebanon.

What is your religious background?

I was bar mitzvahed to please the older generation. We went to the neighborhood synagogue, Temple Sinai, for very special occasions. It was the typical Jewish middle-class, drifting-away-from-your-roots story. I know a bit of Yiddish and can do a Grossinger’s-style [Catskills] shtick.

How did you learn Yiddish?

There was some spoken around the house, which was classically the case when my parents didn’t want me to know what they were saying.

Liz Harris

Liz Harris is a J. contributor. She was J.'s culture editor from 2012-2018.