How about this camera for watching cave entrances?

[hewhocaves]

In lieu of people visiting WNS cave entrances, how about this? It takes exposures at x intervals for days and weeks.

http://www.wingscapes.com/catalog.aspx? ... irdcameras

Home Depot apparently sells the 8MP model for $200-. I think even the 4 MP might have sufficient resolution to show dead bats outside a cave entrance. Set it up somewhere inconspicuous, leave it go for a couple of weeks, come back and see what's been. An advantage to the time lapse photos would be that you could see how frequently corpses disappear from scavaging, which would give a better idea of how many bats are actually dead. I don't know if you could catch bats on the fly with it.
Another advantage is its price - its within the reach of most grottoes to purchase. This gives a grotto another opportunity to add to the WNS data.

And after this is all done think of the awesome time lapse series you can take underground - waterfalls changing volume, streams rising and falling, et cetera.

[George Dasher]

Kentucky is already using infrared cameras to count the bats going in and out of some cave entrances.

Their intent is to monitor the numbers, and they are looking for big increases in the number of bats flying in and out of the entrance in winter.

This is real-time information, as the cameras are hooked up to some kind of radio transmitter.

I'd be willing to bet some other states are also doing this.

[hewhocaves]

I would have expected some sort of bourbon-based technology.

[George Dasher]

It might be bourbon based. You never know.