Folk singer Pete Seeger asked "Where have all the flowers gone?"

UC Davis butterfly expert Art Shapiro wants to know "Where are all the Monarchs?"

In the current edition of the Bohart Museum Society newsletter, Shapiro notes that California populations of the Monarch butterfly (Danaus plexippus) "are notoriously unstable, fluctuating wildly in numbers."

"Because the Monarch is just about everyone's favorite butterfly, certainly the best known, the public is interested in how it is doing," he wrote. "This year it is doing very poorly indeed, at least in the Sacramento Valley."

See, Shapiro tracks Monarchs (and other butteflies) throughout much of Northern California. He's been doing that since 1972, using "a combination of fixed study sites visited every two weeks and more casual 'at large' observations."

His permanent sites include the Suisun Marsh and Gates Canyon (near Vacaville), both in Solano County; West Sacramento, Yolo County; and North Sacramento and Rancho Cordova, Sacramento County. "Monarchs have been present at all of these sites every year, and bred at most of them nearly every year, until 2008," Shapiro wrote.

"As of Sept. 10, no Monarchs in any life stage have been seen at West Sacramento, North Sacramento, Rancho Cordova, or anywhere else in the Davis-Sacramento area. This has never happened before. I've spent just over 60 days at these three field sites this year, and my eyes have been open every day. So this is significant."

Personally, I don't see Monarchs, either. The last Monarch I spotted was along the Mendocino Coast, near Timber Cove, and that was on Oct. 19, 2007.

It looked drenched from the rain.

I photographed it. The next morning, I looked for it and it was gone. 

(Note: For more information on butterflies, see Shapiro's book, "Field Guide to Butterflies of the San Francisco Bay and Sacramento Valley Regions.")