Painted lady butterflies will flutter about the desert for another two weeks in a rare migration event due to the abundant rainfall in the Southwest over the last month, a local conservationist said Wednesday.
Vanessa cardui is the scientific name for the butterfly species “rampaging across the Coachella Valley,” The Living Desert director of conservation James Danoff-Burg said.
“Those butterflies are not normally nomadic,” Danoff-Burg said. “But, on some years of really stellar resource availability, they will just go to town and their apparent populations explode.”
The butterflies normally stay in one area, but “they are coming up the valley probably from south of us, probably from Mexico — Baja Peninsula, for example — and these animals are just exploring the world and seeing where there’s more resources, so they are going further north as a consequence,” Danoff-Burg said.
Resources for the butterflies include food, as well as more plants to lay their eggs on, Danoff-Burg sid.
Danoff-Burg, an entomologist by training, admits that not much is known about the migration of the butterflies as this pattern is so rare compared to butterfly species that migrate on a regular basis, such as the monarch butterfly.
The butterflies could be expanding their range, moving to a new location or simply dying off in the winter, he said.
Although the specifics of the butterfly movements are not clear, Danoff-Burg expects the butterflies will all be gone from the desert in a week or two.
Danoff-Burg’s main job as director of conservation at The Living Desert is to work with communities to ensure they are a part of the conservation efforts as a way to enhance human survival. He recommends that desert communities can support future journeys of the painted butterflies through a variety of steps.
Mostly residents can help by planting more of the native plants that supply food, water and nesting grounds for the butterflies, such as desert milkweed, Danoff-Burg said.
“There’s a lot of food available, but if they want to be successful, ideally they are not laying their eggs on the same plant that hundreds of other butterflies have laid their eggs on,” Danoff-Burg said. “So they want to disperse to get new areas for egg laying, as well as food for their larvae.”
Other suggestions for conserving the species include “folks can drive slower” to not kill as many, “as much as we can reduce the direct mortality through efforts of passing through the valley, that’s great.”