The U.S. Fish and Wildlife Service Tuesday published a proposal in the federal registrar to list both subspecies of the Regal Fritillary under the Endangered Species Act. Montana State University Dept. of Ecology Department Head Diane Debinski says the butterfly is about the size of a Monarch.
“They have the orange and the black, but they have big white spots and a big of a purple tinge to them,” Debinski said.
While the eastern subspecies of the butterfly survives in only one small part of Pennsylvania and is at risk of extinction, the range of the western subspecies still includes 14 states as far west as eastern Wyoming and Colorado. FWS is proposing to list the eastern subspecies as endangered and the western subspecies as threatened, a status that means it’s likely to become endangered.
Debinski said the loss of native prairie and grassland is one of the major factors affecting population sizes.
“The violet species that the caterpillars use to eat as they’re growing are often not seen in places where the prairies have been plowed or the prairies have been turned into cropland. They can be seen in places that have been grazed, which is a good thing,” Debinski said.
The FWS listing would direct resources to conservation of the western subspecies, but also maintain activities like livestock grazing, which spares ranchers from needing to apply for approval.
FWS is taking feedback on the proposal through October 7.
