Monarch butterflies in the West have hit a record low, according to a conservation group that tracks their numbers.
The Xerces Society for Invertebrate Conservation does regular counts of the western monarch when it spends the winter on the West Coast. Its latest published count found the population has dropped below 30,000, which according to the group is “the number researchers set as their most educated guess for the threshold at which the western monarch migration could collapse.”
Though counts are regularly done along the coasts, Sarina Jepsen, director of endangered species and aquatic species with the Xerces Society, says conservationists need a lot more information about the butterflies in the Mountain West.
“Colorado, Utah, Montana, Wyoming -- and I'd add New Mexico to that -- is really the area of the entire country that we know very little about,” says Jepsen.
In a call to action to “avoid a total collapse of the western monarch migration,” the society and partner institutions across the West are asking that people report sightings of monarchs and the plants their caterpillars eat -- milkweed -- on the website Western Monarch Milkweed Mapper.
Jepsen says trends among the monarch butterflies, which are much more consistently studied than many other insects, could be considered a barometer for other species.
“I think it's very likely -- and certainly some limited studies corroborate this -- that many other butterflies and really many other insects are facing a similar fate,” she says. “Yes, we're talking specifically about the monarch butterfly here, but I think it's also showing us that there's something going on in the landscape -- something going on in our ecosystem -- that is hurting monarchs and potentially many other butterflies.”
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Boise State Public Radio in Idaho, KUER in Salt Lake City and KRCC and KUNC in Colorado.