April 23, 2014
Southwestern Myotis about to drink, Coronado National Forest, Arizona, and the Cognysis StopShot

This image of a Southwestern Myotis (Myotis auriculus) in flight and about to drink would not have been made without the insight and assistance of my partner Jan Forseth. You see, when we arrived at the location in the Coronado National Forest, the animal watering tank where we were going to photograph bats was empty: no water, no bats coming in to drink, no bat images. Not only was the tank empty, but the pipes leading to it from a small dam upstream on the adjacent stream had been disconnected, and no water was flowing out of the first pipe from the dam. Fortunately, someone had provided several sections of new pipe, so Jan and I started hauling them into place. We didn't make much progress before a thunderstorm arrived. After dinner and after the rain stopped, I went out in the dark and hooked up some of the new pipe sections to go from the dam to the last section of original pipe that emptied into the tank. I used duct tape for the joints until that ran out then I used packing tape. I was pretty sure something like this had been done on an episode of Gilligan's Island, except they didn't have to contend with cow patties and (probably) cow urine in the very shallow and aromatic slow-running stream. Unfortunately, after the plumbing work, no water flowed from the dam to the tank, but water was getting at least as far as the first connection because it was leaking slowly. I went to bed feeling very dejected. Several thunder storms went by that night and the next morning.

After the rain stopped on that second afternoon, Jan came out with me to look at the situation. The stream was a little higher from all of the rain, but water still wasn't reaching the tank. Based on her observations, I built-up the dam to force more water into the new pipe, but still no water flowed into the tank. Then Jan suggested that maybe the pipe was like a syphon. I quickly dismissed that idea because after walking up and down the length of the pipe many times, I was quite certain that the whole length of pipe was a downhill run and wasn't like a siphon. Plus, I wasn't going to suck on the far end of the pipe knowing what was going into the pipe. Because of the possibility that the last section of original pipe, the one that emptied into the tank, was damaged or clogged, Jan helped me replace it with the final piece of new pipe and a different section of old pipe. Now we had a completely new run of pipe from the dam to the tank and still no water reached the tank. Most of the joints were leaking, so water was getting part of the way to the tank. Jan went back to the RV and I kept thinking about the situation. The last joint was leaking by this time, so water was getting almost all of the way to the tank. Maybe Jan was on to something with the siphon idea, so I took the pipe out of the tank and draped the end down in the stream bed to see if that would help. Sure enough, after a while, water started flowing out of the end of the pipe, and boy did my morale improve! It took two tries to get the pipe back up and into the tank with the water still flowing, and I was ecstatic that the tank was finally getting filled. I was also a bit embarrassed that I, with a Ph.D. in computational fluid dynamics, hadn't solved the simple plumbing problem by myself. Based on the flow rate, I expected it to take a few days to fill the tank, so I was very surprised, and thrilled, when the tank was full the next morning!

We set up to photograph the bats that evening, but the process took a little longer than I thought and we didn't capture any bats. However, something did trip the flashes while we were doing the final camera setup which was a good sign. The second night, I captured 1.5 bats. I cut off the wing tip of one bat and only got the wing of another. Last night, I finally got some good images: three bats completely in the frame. This is my favorite image by far because the bat's just about to take a drink so there aren't any distracting water drops flying around. It's a nice pure reflection shot.

This is the bat photography setup at the animal watering tank, and it's a view from roughly where the cameras were positioned for the actual shoot. The tank's about 8 ft (2.4m) in diameter and about 2 ft (60cm) deep, and it's mostly buried in the ground. The first thing we did was lay down some black cloth across the bottom of the tank and against the far side of the tank to prevent unwanted light from reflecting through the water and picking up a green cast which is what happened when we photographed here about four years ago. Then we set up a Cognysis StopShot camera trigger with two laser beams to fire six Sunpak 383 flashes when a bat flies through either beam. The flashes were set to 1/16 power to create a very short burst of light.

This is a closer view of one side of the bat setup. The two flashes on the left provide half of the front illumination and the single flash on the right provides some rim lighting. The laser receivers are in the center. Manfrotto Superclamps, and the similar Impact Super Clamps, secure the items the rim of the tank, and the flashes are supported by small ball heads. The two main flashes are mounted next to each other on a custom flash bracket and the rim-light flash is held up higher by a fully-extended 11-inch (28cm) variable friction arm. The laser receivers are supported by an 11-inch (28cm) variable friction arm and a custom mounting plate.

The cameras were set to make 10 or 15 second exposures and set to fire repeatedly using a cable release with the button locked down. The actual image is made by the very short flash burst which illuminates the bat and stops the motion. After two or three hours of automatic and unattended operation, we returned and took down the cameras and StopShot setup. Then we looked, with great anticipation, through the mostly all-black images for the ones with a bat.