Bat talks and walks at Yolo Bypass this summer

For the schedule of events and to learn more about bats visit

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As summer approaches, the bats of the Yolo Causeway return. Although we do not know where they spend the winter, each summer about 250,000 Mexican free-tailed bats (Tadarida brasiliensis) return to their summer home, where they live in the expansion joints of Interstate 80 between Davis and West Sacramento. This is the largest urban colony of bats in California. These little winged mammals consume their weight in crop pests and other insects each night, providing a valuable service to farmers and backyard gardeners.  The Yolo Causeway bat colony helps the rice, almond, walnut, corn and tomato growers, in addition to eating some pesky mosquitoes. This maternal colony emerges near sunset and disperses throughout the area. The concrete crevices under the freeway provide safe, warm roosting locations for the mothers. Each mother gives birth to one pup in late June and by mid-August the young bats join the adults on the insect-eating frenzy. These small, swift, long distance travelers can fly almost 100 miles per hour and travel up to 2 miles high, chasing and eating hundreds of moths whose larvae can devastate crops and backyard gardens. Insects such as the cutworm, codling moth larva, corn earworm and armyworm are caterpillars of moths. DeWit Family Farms, who grow the rice in the Yolo Bypass Wildlife Area, credit the bats for the protection of their crop, allowing them to avoid using any insecticide to protect their rice. A nursing mother must eat her weight in insects each night to produce the very rich milk needed to nurse her pup. These amazing mammals act as natural pest control. Watching the bats emerge from the freeway is an unforgettable sight. At times, one is lucky enough to catch the flight while driving across the Causeway but it is hard to view at 65 miles per hour. Join a tour with Yolo Basin Foundation to truly enjoy the experience. The program includes viewing live native species of bats and a family friendly PowerPoint about bats where participants learn about the lives of these amazing hunters of insects. Finally, we caravan through the Yolo Bypass Wildlife Area to the viewing location and watch the bats exit in a spectacular flyout. Yolo Basin Foundation also hold special bat events during the summer including Bats and Crafts for young children, Bat House Building, Bats and Brew and more. For the schedule of events and to learn more about bats visit  ]]>

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