Bats


Beach Club Bat House


Beach Club Bats 07-26-2017  234549c

On July 5, 2017 the von Arx Wildlife Hospital at Conservancy of Southwest Florida received a call that a bat house at The Naples Beach Hotel and Golf Club had fallen down in a storm. This was the third call of the day to assist bats that had been displaced by passing thunderstorms.


When the hotel staff took us out on the seventh fairway, we found a large bat house on the ground. Someone had propped it upright keeping the hundreds of bats from being rained on.


While a few bats died in the fall, most were doing well. The house contained a maternity colony. Many of the young bats would need several more weeks before they would be ready to fledge.


The best option for a happy out come was to keep the bats together in that area and let the mothers continue to raise their young. The pole that the house had been on was rusted through. Putting the house back on it was not an option. The best available option was to place the house in a nearby ficus tree. The multiple branching trunk, provided a secure location so that the house would not fall in another storm.


Over the following month we continued to monitor the bats. As the young bats matured and fledged, they gradually moved out of the house. By August 8, 2017 all of the bats had moved own.


July 10, 2017


July 11, 2017


July 12, 2017


July 26, 2017


Bat Photography

With the help of my friend Franklin Viola, we have been working on a support system that will allow us to get better bat photographs and video. The challenge is to have the camera pointing straight up, the bats well lit, and the platform to be stable. This is what we have workout so far.


The Brazilian free-tailed bats, (Tadarida brasiliensis) living at our house in Everglades City have helped with this project.


NR-2 May 18, 2017

This is a more detailed look at the Bonneted Bat Roost NR-2 at the Babcock-Webb WMA.  On projects like this I try to get the most out of each opportunity. Below are the results from four different cameras, each with slightly different imaging technology. 

Sunset was at 20:10. The temperature was 84 degrees F. and the wind was 15 to 23 knots. With that much wind, there is a bit of movement in the roost tree and during gusts the cameras also were shaken. The constant wind created a lot of wind noise, most of it I have muted. 

During much of the recording I had an Echo Meter near the cameras so that you can hear the bats echo locating.  Because of the distance from the roost tree to the cameras, you cannot hear them echo locating in the cavity, but if you watch closely, you can see them doing it.

The first bat emerged at 20:50, forty minutes after sunset. A total of seven bats emerged.


The first video is a slow motion video. It was made with a Sony Alpha 7Sii camera and a very fast f 0.95 lens. This video is made with visible light. While the camera has amazing low light capabilities, it was not able to capture the last two bats to emerge, because of the low light levels. This is the camera that I use to capture Realtime Northern Lights.


The next set of videos were made with a Sony AX53 Handycam in night vision mode. The zoom lens was at its maximum setting of 536mm.

The first video is the short version, just the bats emerging from the cavity. The second video is the long version, showing all the activity at the cavity.



The next set of videos was made with a Nikon D5 camera attached to an AstroScope Night Vision scope and a 400mm lens.

The first video is the short version, just the bats emerging from the cavity. The second video is the long version, showing all the activity at the cavity.



The final set of videos was made with a Nikon D800 camera converted to use the full spectrum of light. The conversion by Kolari Vision allows the camera to record ultra violet, visible , and infrared light.

The first video is the short version, just the bats emerging from the cavity. The second video is the long version, showing all the activity at the cavity.



Bonneted Bat Roost

Thanks to the hard work of the FWC and University of Florida biologists we know of another natural roost of Florida Bonneted Bats (Eumops floridanus). The bats are using an abandoned red cockaded woodpecker cavity in a live pine tree. The video below was make using a night vision camera on a long telephoto lens.


Searching for Bonnie


After three years of searching in the Big Cypress National Preserve we have found a roost of the Florida Bonneted Bat (Eumops floridanus). Our acoustic monitors lead us to an old woodpecker tree at Raccoon Point. On two occasions we peeped the cavities in this tree but did not see any bats. Because the accoustic monitors kept leading us back to this tree and bat guano was found at the base of the tree we decided to stake it out at emergence time.  Last night, 27 minutes after sunset the first bat emerged.  Over the next hour, ten more bats followed. Their size and recorded calls confirmed that they are Bonneted bats.

Deborah Jansen peeping for bats.

The roost tree.

Video of the bats emerging.

Peeping the cavity at 55 feet.

The camera is custom made by Emmett L. Blankenship, DVM,MS. emmettdvm@netzero.net

Bat Conservation International provided the camera to The Big Cypress National Preserve. 


© Ralph Arwood 2017