Five Bat Species

I was out underneath the western end of the I-80 Yolo Causeway again shortly before sunset on 4/29, listening to the batspeak in the vast colony there with my Bat Echometer. Once again, Mexican Freetail Bats were common (as the Echometer ID'd in the picture below), as were Hoary Bats, but as sunset approached, the squeaking chatter grew louder, and other bats began drowning out the more-common bats, namely the Yuma Myotis, the Canyon Bat, and the Western Red Bat. These five bat species are common enough in the Davis, California area, but I didn't realize they all live right next to each other, cheek by jowl. It must be bat heaven there under the Yolo Causeway. Once again, I never actually saw the bats (although one apparently pooped on my head). The rising cacophony was exciting. The mass flights of summer are approaching. I can hardly wait!

I'm worried about the small Midtown Sacramento colony of Mexican Freetail Bats. They've begun a large construction nearby, and although the bats aren't directly affected, all the noise and fuss nearby might be problematic.