by tropicalbats » Nov 29, 2006 1:55 am
Wow, a lot going on here. Some easy, some complicated.
Easiest is that yes, bats do have rather good vision. Hitting them with a flash gives them roughy the same vision trouble we get from that. But, even after photographing a bat at night, they can fly off with sonar and wait for the eyes to get over it.
Also easy is that taking a picture of a bat in a cave disturbs it.
what is far more complicated is the impact to the bat.
There are now around 1,100 species of bats known in the world, covering everything from carnivorous bats, nector bats, etc. So, to start saying anything about "bats" is to immediately need to qualify every remark as it won't necessarily apply to all or even most bats. I expect no one will object if I go this route instead:
The main issue here is probably taking photos of hibernation bats, ie, bats in caves during the hibernation season. Here's the broad brush for hibernation. If you photograph a bat in a cave, you have almost certainly woken it up. It will need to spend some energy to wake up, it will then likely take a pee, drink a bit of water, and then put itself back into hibernation. The science shows that this often happens at least 30 minutes after the disturbance, so unless you hang around for a good while, you are unlikely to actually see the results of the disturbance.
And a few specifics. Bats have to wake up on their own anyway during the winter to do this stuff (on average, for a little brown bat, every 15 days). So, such a disturbance will wake them up, and if it's roughly when they'd wake up anyway have little impact. If it's just after they've gone back to sleep, it will effectively "add" an un-justified wake-up to their energy balance. Their energy budget allows less than six of these types of "added" disturbances (0 for highly environmentally stressed bats, up to six for optimally situated bats) before they have physiological consequences. The most important (and invisible) of these consequences is that a female bat will catabolize the stored male sperm (they mate in fall, store the sperm, self-fertilize in the spring) and thus not produce a young. Net effect is killing 0.91 bats (the average birth rate among female little brown bats).
So, the short end of it is that yes, taking a photo impacts the bat with possibly significant consequences. I am somewhat less eager to visit this end of things, but the answer to an earlier bit is that yes, it is generally illegal to photograph a hibernating endangered bat, but highly unlikely the gov't will go after you for a single photo.
However, all that under the bridge, the common sense bit is this. If you are a photographer who can take a high-quality shot of a bat that you believe may be of interest to biologists from a cave not known to have interesting bats, it could be justified. Going into a known endangered bat hibernacula is iffy anyway, and since no one needs more photos in this case you'd run the risk of getting into some trouble. Other than this, if you just want a couple of pictures of cave bats for your album no one is going to go crazy over it but please keep it to a minimum, and for the most part don't put them on the web.
Of note. We who work with bats are the first to acknowledge that we disturb them. It is obviously necessary for the work. But we also have to get permits, from the US, from the state, from foreign countries...you name it, we have to justify to other professionals why our disturbance is worth it. Cavers should maybe just give a thought about whether you are disturbing the bats and how much and for what reason.
My general rule is that if you are just out caving, and see a lot of bats, well, you probably should retreat and choose another cave or different area of the cave you are in.
Keith