Anytime a hurricane threatens here in the South, we get a lot of questions at the butterfly free-flight exhibit where I work about what we do to protect the butterflies from the storm. The answer? Nothing, really. Butterflies, like all wild creatures, are equipped to handle some pretty nasty weather, though butterfly gardeners can help out a bit by providing the right kinds of habitat.
Just like humans, when rain threatens, butterflies seek shelter. When you’re a butterfly, a single raindrop is an awfully big deal. The average monarch butterfly weighs in at around 500 milligrams. The average raindrop weighs around 70 milligrams. Scientific American suggested that the impact of a raindrop on a butterfly would be similar to a human being hit with a water balloon with twice the mass of a bowling ball. Yikes!
So, butterflies look for shelter when the skies start to grow dark. They cling to the undersides of leaves, climb deep into tall grasses, or tuck themselves into cracks of rocks or trees. This is also how they protect themselves from strong winds. Their feet are capable of a surprisingly strong grip, and as long as they stay still in their sheltered spot, they’re likely to ride out the storm just fine. (Caterpillars do much the same thing, although they seldom stray far from their host plants.)
Of course, extremely severe weather can have an impact on butterfly populations. A large hurricane may destroy habitat, especially on islands and coastal areas where salt water flooding may kill host and nectar plants. In the Florida Keys, both Schaus Swallowtails and Klot’s Palatka Skippers have very limited ranges, and when hurricanes like Andrew destroyed much of their habitat, their populations began to struggle. Most butterflies have much larger ranges, though, and if they experience die-off in one area due to a storm, butterflies from nearby unaffected areas will quickly move in and repopulate when the habitat recovers.
As a butterfly gardener, you can help butterflies during stormy weather by making sure your garden has places for them to seek shelter. Trees (dead or alive), tall grasses, and even rock piles provide great places for butterflies to hide during bad weather. Butterflies also use these shelters at night, when they rest.
What about “butterfly houses”? You’ve probably seen these advertised or sold along with bird houses. They are usually small wooden houses with slits for butterflies to crawl inside, and perhaps perches for them to cling to. Honestly, I’ve never really seen a butterfly using one of these, and they usually wind up becoming a place for wasps to nest instead. You can try one out, if you like, but it’s probably less expensive and easier just to plant some ornamental grasses or sturdy shrubs.
Have you ever seen butterflies taking shelter before a storm? What kind of shelter were they using? What about “butterfly houses” – have you had any success with them? Tell us your experiences in the comments below.