Bats and Bats!

I was out this evening near a bridge that crosses over the Pantano Wash on Broadway here in Tucson and snapped a pic (as usual, click to embiggen).
This might just look like another sunset picture with Venus. However, if we zoom in close on the bottom, something else pops up.
Look closely and you can see some faint dark streaks on the image. Those are bats. I had to take a few tenths of a second exposure to get the image and they were flying pretty fast so they show up as dark streaks (I didn't have a tripod with me so I handheld this...blurring the image slightly in spite of an image stabilized lens).

Bats are pretty common here. About 30-40 minutes after sunset, you can watch them start streaming out from underneath lots of the bridges here. There were probably about a dozen people there watching them tonight. I have seen them before, this just happens to be the first time I had my camera with me and tried to see if I could get any images of them. Estimates of the number of bats per bridge range from 10,000-40,000. This bridge is believed to have one of the bigger colonies (but not the biggest which is the bridge over the Rillito River on Campbell Ave, but that one is way across town!)

Here is one more pic of them, but without Venus.