Hundreds of butterfly species across the American West are vanishing as the region becomes hotter, drier and more vulnerable to the effects of climate change, according to a study released Thursday. "Even if you just took the professors that were on this paper, all of us, we couldn't cover that geographic area," said Katy Prudic, an entomologist at the University of Arizona who helps run one of the online butterfly database. "There's just not enough of us. So this work, the comparison across the entire West, could not be done without citizen science."