Texas Bridge Bats

I've been fascinated with bats for a long time.  I've gone down to Town Lake to see the bats emerge from the Congress Avenue Bridge. I've been to the Old Tunnel Wildlife Management Area and seen the bats emerge a number of times.

If I'm on I-35 in Pflugerville or Round Rock at dusk, I've seen bats emerge from the Wells Branch Bridge, the Howard Lane Bridge, and the McNeil Bridge.

I've gone out a couple of times to try to get some good bat photos. The first time I tried, I couldn't get the right angle for the shot I visualized - the silhouettes of the bats against a colorful sunset sky.  I've been helping with the bat interpretation at the McNeil Bridge, but if I'm talking to people, I'm unlikely to be taking time to photograph.

But Friday night things came together, the clouds in the eastern sky took on a pinkish hue, the bats were a little later than normal coming out, and another picture that I had visualized looked promising.  When the bats emerge from the bridge, they fly to the east to forage over the agricultural fields and pastures in eastern Williamson County.  They make beautiful patterns in the sky as they disperse.  I wanted to capture those beautiful and actually mathematical patterns.

It takes over several hour for the 1.8 million bats to leave their roosts.   But it is an amazing spectacle.

It is amazing to me how the flow of bats weaves itself across the sky, at times almost moving as though there is a common intelligence guiding the patterns. 

 

Late summer is a good time to view the bats because this year's pups have joined the flow.  

My article about the free-tailed bats is in this week's Hutto News.

Henry has a new app for his phone, Radarscope.  He came into my office near sunset asking what time the bats come out.  It turns out that you can see the images on the radar from this app that show the density of the bats emerging from a number of places around us in Central Texas.  Check out his blog and see the video he made of the radar images this evening.

Old Tunnel Wildlife Management Area

Henry and I have both been feeling a little cooped up so we decided to go out for a drive on our anniversary. I had some business I needed to take care of in Fredericksburg so we headed in that direction.

The highlight of the day was sunset at Old Tunnel Wildlife Management Area. Amazingly enough this is the smallest wildlife management area in Texas (16.1 acres) with the most mammals of any wildlife management area. At the peak of the summer bat season, over 3 million Mexican Free tailed bats live in the old railroad tunnel. Each night volunteers give a presentation about the bats before it is time for the bats to leave for the nightly hunt. Thursday through Sunday there is a lower observation area open for a small fee to get a closer look at the bats during the exodus.

We arrived early and I got a front row seat with my big lens. There were a couple of hawks, one a red tailled hawk, who were cruising the area. The volunteer thought the presence of the raptors might be a signal that the bats would leave early. I was watching the hawk soaring when all of a sudden it tucked its wings in and did a spectacular nose dive. Sure enough the first bats were exiting the tunnel!



When I first set up my big Sigma lens, I was afraid it was going to be too big. Light was not great, so I chose a high ISO so I could keep my shutter speed fast enough to get stop motion on the bats. My goal was to get some close shots as they exited the tunnel. I was also hoping to get shots of the big picture - the patterns of the bats as they spiraled up in the sky before dispersing for their feeding.



The females and young have not yet taken up residence in the tunnel, so the spectacular show of the bats lasted only about 13 minutes. When we were there later in the year, I think it took 45 minutes for all of the bats to leave the tunnel.

I was actually glad we were on the upper deck, because I think i got better shots of the bats and the surrounding landscape. But i would also like to go back with the Canon 100-400 lens and get some shots from the lower deck. No flash is allowed, so I'm hoping to go in July or early August and hope that the bats will be leaving before it gets too dark.

Truly an amazing spectacle to see the sky so filled with these small amazing creatures.