Read the full article by Lisa Thibodeau at The Sacramento Observer
On any given summer evening, as construction crews work and traffic hurtles over the Yolo Causeway, which connects West Sacramento and Davis, something mysterious is percolating below.
A large colony of Mexican free-tailed bats, who have spent the day sleeping under the warm concrete of the 3-mile-long bypass, begin to stir. As the bats awaken and their chatter becomes louder, they begin their sunset flyout in long, elegant ribbons from beneath the causeway in search of their dinner.
This Yolo County colony is the largest in California, with as many as 250,000 bats that roost and birth their pups yearly in the 16,000-acre Yolo Bypass Wildlife Area with its restored wetlands and rich habitats. Bats, which are the only mammals that fly, use their long, narrow wings to quickly (up to 99 mph) lift up over the rice fields and nearby farms in Yolo and Sacramento counties to consume the equivalent of about 500 grocery sacks full of insects nightly.