Butterfly May Have Just Taken 'Elevator to Extinction'

One very small death in Albuquerque may signal a much bigger problem. The last known Sacramento Mountains checkerspot caterpillar in captivity has been declared dead, leaving scientists unsure whether the rare butterfly still survives anywhere in the wild, reports the New York Times. The caterpillar, raised at ABQ BioPark in Albuquerque, New Mexico, from one of more than 160 offspring produced by four wild-caught butterflies in 2022, never completed its metamorphosis, despite living longer than expected. Researchers tried inducing hibernation and slowly warming it this spring, but the insect never woke; they called its death on May 5.

The subspecies, found only in New Mexico's Sacramento Mountains, has been hammered by warming temperatures, changing fire patterns, grazing, invasive plants, and recreation, federal wildlife officials say. It hasn't been seen in the wild since 2022. "We're very, very concerned about the future of this species," says invertebrate specialist Quin Baine, per KRQE. Scientists will resume searches earlier than usual this year, as butterflies are coming out sooner in the heat, per the Times. The insect's frozen body will be preserved for genomic research. Its story, meanwhile, according to Baine, serves as a warning that many other species may be slipping away unnoticed—an "elevator to extinction," with fewer and fewer places left to go.