Oh, I didn't know that!

Friday last week, I had the great pleasure to attend a talk about butterflies and California native plants, sponsored by the Santa Clara Valley chapter of CNPS. The presentation was by Liam O'Brien, who used to be an actor but fell in love with butterflies and is now a butterfly expert. He has prepared beautiful Trail Signs, a foldout to identify butterflies of the Presidio, and is  involved with the Green Hairstreak project. The talk was both educational and entertaining, short of bursting out in song, Liam did what he could to keep our attention and I was quite sorry when he was done.

I was immediately taken when Liam started by showing one of my favorite plants, Aristolochia Californica.

I know that this is the only host plant for the pipevine swallowtail, a beautiful blue butterfly. Pipevine swallowtails are not currently found in the Santa Clara valley - or are they? Liam explained that Aristolochia is left from the time when the whole continent was a jungle, and that the pipevine swallowtail has different flight pattern than most other butterflies. It's hard to predict where she will show up - all we know is that she will always lay her eggs on Aristolochia. A jungle butterfly? Well, I didn't know that.

And here's where things got interesting. I knew and I didn't know that butterflies are happy to take nectar from any pretty, colorful flower that might come their way (that's why you might see butterflies even at the Home Depot garden center). But she will lay her eggs only on very specific plants, because the caterpillars only like certain food and cannot survive if they can't get it.

So, any old food, but not any old baby bed at all. And this is where native plants come in: many of the butterflies found in the SF Bay Areas can survive only if they can find the plants that they evolved with.

For example, skippers must have native bunch grasses.

The west coast painted lady and the common chequered skipper like mallows such as Sidalcea malvaeflora.

We can find 34 species of butterflies in San Francisco, and only one of them is not native (the white cabbage butterfly). Liam said he expects that about twice as many can be found in the Santa Clara valley (though maybe not right next to the freeway, I might add).

Some of the butterflies have become generalists, branching out from accepting only the native willow to any willow at all, native or not (Western Tiger Swallowtail). Others insist on one species within a native family. For the Green Hairstreak, it's Eriogonum latifolium (coast buckwheat), nothing else will do. Nature in the city is working on planting coast buckwheat and encouraging the people who garden in San Francisco to plant coast buckwheat - I hope the butterfly will make it.

Another surprise was yarrow. Butterfly plant, right?

Well, here's the secret: This plant offers no nectar to butterflies, but they like to use it for mating. Nice and flat, above ground - hey, perfect spot for a little fling.

And speaking of plants and butterflies - I was surprised to hear that butterflies are not pollinators. Bees, wasps, and flies are pollinators. Butterflies are.... bird food. Yes, sad but true. Birds love to eat the caterpillars, crysalis, and the beautiful creatures that fill our hearts with joy, make us dream of summer, and inspire poets and artists. It was quite sobering to hear how very few of the eggs make it to the butterfly stage - and even then, a high percentage doesn't make it to mating and motherhood.

I left the talk inspired to learn more about the butterflies in our area and their host plants, and to make sure I have host plants for as many as possible in the garden. Fortunately, my neighbor has a willow, and I just added a Lupine to my collection. And I really want to learn which butterflies I might find in my garden - and maybe I'll go on a butterfly walk some time soon to get better about spotting them. Then there's the difference between butterflies and moths: Butterflies have clubbed antennae (I didn't know that!) and there are 750 species of butterflies and - get this - 300 000 species of moths.

I think I'll start with the butterflies!


Jason said…
Great post. I'm also very into butterflies. I've planted lots of milkweed for monarchs. I also have spicebush in part for the spicebush swallowtails, and I just planted our native pipevine(A. macrophyllum) for the pipevine butterflies.
Unknown said…
Excellent article. Thanks!