Turning Over an Old Leaf

It's New Year's Day and it's common for folks to turn over a new leaf.

What about the old leaves?

Sometimes if you turn over an old leaf this time of year in Solano and Yolo counties, you might find a monarch caterpillar. As of today, we have two monarchs munching away in our pollinator garden in Vacaville. They've survived through freezing temperatures, heavy winds and steady rain.

Back in the late summer and early fall, monarchs fluttered into our gardem to lay their eggs. We provide four species of milkweed. Every fall we cut back the milkweed, but not until all the 'cats are gone. This year the 'cats  "weren't gone."

Monarchs surprise us. Some of our December/January sightings:

  • A monarch in flight on Dec. 16, 2023 in west Vacaville
  • A monarch in flight on Jan. 3, 2023 near Vacaville High School
  • A monarch caterpillar munching Jan. 23, 2021 in our garden.

We remember UC Davis distinguished professor Art Shapiro (now emeritus) of the Department of Evolution and Ecology telling us that he recorded a monarch in flight on Jan. 19, 2020 in Sacramento, but even earlier than that--UC Davis professor Louie Yang of the Department of Entomology and Nematology spotted one flying Jan. 8, 2012 in east Davis.

Shapiro, who has monitored the butterfly populations of Central California since 1972, maintains esearch website at http://butterfly.ucdavis.edu/.  His 10 sites stretch from the Sacramento River Delta through the Sacramento Valley and Sierra Nevada mountains to the high desert of the Western Great Basin. It's the largest and oldest database in North America, and was recently cited by British conservation biologist Chris Thomas in a worldwide study of insect biomass.

The monarch Shapiro saw on Jan. 29, 2020, however, wasn't in his research project. As he told it in an email to his posse:  "We had a visitor today--a British journalist--who wanted to go on a site walk. Rancho Cordova was next up. We went in his rental car. We were on US 50, just passing the Tower Theater in Sacramento heading eastbound, when, at 10.30 a.m. (temperature in mid-upper 50s, light North wind, mostly sunny), a Monarch, sex unknown, flew across the freeway in front of us, 20-22' up, from SW to NE. There is no possibility of error, unless I am having visual hallucinations."

And the monarch caterpillar we saw in our garden on Jan. 23, 2021? "Evidence of inland winter breeding," Shapiro told us. "Nothing surprises me any more..."