The Bat Detector Survivor

This December Cumbria was hit by several devastating storms that caused wide-ranging floods and immeasurable devastation.

If you were affected then you have my utter sympathy and I hope you are getting back on your feet.

I was fortunate that I was not directly impacted. However, I was working on a site that was much closer to a river, near Carlisle.

We had carried out summer surveys at this old mill site and found bats roosting individually in small crevices in the building, but we had also noticed that the property had an underground culvert and a cellar-like kiln, both of which presented some winter hibernation potential to the building. We therefore decided that a hibernation study was in order.

Hibernation surveys often involve the deployment of static bat detectors to record bats flying within the building. Bats, of course, although generally asleep over winter, will still move around and so it is these that we try to record with the detectors.

We therefore installed two detectors in this mill, one Anabat SD1 in the kiln and one Anabat Express in the culvert.

Less than a week later, Storm Desmond started to make the news. Predictions of record levels of rainfall were being broadcast and potential widespread flooding.

Worried that the river may flood the mill site, and with it our equipment, on the Saturday morning Lucy and I set off to try to retrieve our detectors before the flood arrived. We phoned the neighbours who confirmed that the site was not yet flooded. However, Kendal was. Leaving Milnthorpe for Kendal, I barely got half way before having to turn around and give up – the roads were impassable.

It was clear that we would not make it to Carlisle and so we were stuck, just hoping that the river didn’t flood too high.

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Devastation outside the culvert

As I am sure you have worked out, out hopes were dashed. After the weekend we received some photos of the site, which had been completely inundated. Not only would the culvert be flooded but the kiln was underwater too.

We finally decided to brave the conditions and head up to Carlisle to retrieve the equipment; not in an optimistic mood.

First to be checked was the SD1. This is an older style detector and although it was housed in a box, it was not waterproof. Upon entering the kiln, it was clear that the water level had been very high; there was debris everywhere. A brief search found the SD1 on the floor in a soggy muddy pool. I instantly knew that it would be a lost cause. Opening the box confirmed it.

Water, silt and corroded metal filled the box. It was well and truly deceased. With it we also lost a remote camera. This was looking pretty disastrous.

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Soggy detector

The final detector to check was the Anabat Express in the culvert. Not only was I worried that it would have been damaged by the water, I also feared that, being positioned in the culvert, it would have actually been washed away.

Fortunately, it was still there, so I collected it out of the culvert to check it for damage. I opened it expecting, like the remote camera, that water would pour out of it. I was wrong. It was almost bone dry. A tiny dribble of water could be seen at the base of the housing. Other than the muddy exterior, it looked completely untouched.

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Anabat Express, still in position

Dare I turn it on? Why not? I pressed the button and to my astonishment, it turned on and all the correct lights started to flash.

This was a detector that, from the reports by the neighbours, had been under water for over 12 hours. 12 hours of complete submersion and still working!

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Sum total of the water damage

When we got back to the office I downloaded the SD card and was stunned that it had continued to monitor the whole time whilst under the water. An Anabat Express records temperatures every 5 minutes, and it had done this the whole time (just taking water temperature not air temp!).

I sent the unit to Andrew Dobson at Titley Scientific, who agreed to give it a once over. His verdict: “…it’s in good nick, the mic was slightly down on sensitivity so I replaced the element…”, but that was it.

To say I am impressed is an understatement. I am so glad that the bat group have invested in a number of these detectors, as they seem to be brilliant devices.

Rich Flight