A young Mexican-free tailed bat lay dead beneath a bridge in Tucson, Arizona, on August 8, 2025. In Arizona and New Mexico, known for their high bat species diversity, Bat Conservation International reports climate change can lead to a significant drop in bat reproduction rates. Dozens of Mexican free-tailed bats fly beneath the Campbell Bridge in Tucson, Arizona, foraging their body weight in insects each night. Kai Enright, a PhD candidate at the University of Arizona, counts bats beneath a Tucson, Arizona, bridge as part of a survey conducted across 32 bridges each month for a year. Gabrielle Mousseau, an undergraduate at the University of Arizona, counts bats roosting beneath a bridge in Tucson, Arizona on August 8, 2025.