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Bat photography..

PostPosted: Nov 27, 2006 9:36 am
by graveleye
This may belong in the conservation section, but I am curious as to the best way to photograph roosting bats. So far we have not used a flash on them because something tells me it disturbs them even if they are sleeping. I do notice however, a lot of folks pictures that are using a flash when taking pictures of the little critters. What do you folks think? Does it bother the bats to use a flash on them?

PostPosted: Nov 27, 2006 3:43 pm
by Bobatnathrop
Ehhh...that is a hard one. I mean you arent even suposed to shine your light on them let alone use a flash.

Most of the bats I've seen sleep with their wings over their eyes. Maybe if it is sleeping like that you could take a picture of it?
If it has it's eyes open and is looking at you then NO dont do it :yikes: You might end up a face full of angry bat.

PostPosted: Nov 27, 2006 5:58 pm
by NZcaver
Err, correct me if I'm wrong but aren't bats effectively blind? Don't they use their biosonar to navigate? :?

Now obviously I don't advocate disturbing the little critters, but some of these precautions about not blinding them may be a little over-the-top...

PostPosted: Nov 27, 2006 6:03 pm
by Squirrel Girl
Bats are not effectively blind.

Try closing your eyes in a dark room and setting off the flash. Tell me if you see it through your eyelids. If so, imagine that that bat has about that much skin in their wings blocking their eyes (plus their little eyelids, too).

Bet it'd be blinding for them (no pun intended).

PostPosted: Nov 27, 2006 6:05 pm
by Squirrel Girl
Oh, I should say that I have no idea how far away you can be and photograph bats and have it be safe. Maybe 10', maybe 50'. Don't know. I'm just trying to point out that bats aren't blind, and at least if the flash is close it WILL disturb them.

I'll have to ping tropicalbats. He'd have a much better answer.

PostPosted: Nov 27, 2006 7:03 pm
by wendy
NZcaver wrote:Err, correct me if I'm wrong but aren't bats effectively blind? Don't they use their biosonar to navigate? :?

Now obviously I don't advocate disturbing the little critters, but some of these precautions about not blinding them may be a little over-the-top...

actually i heard somewhere that bats have very good eye sight

PostPosted: Nov 27, 2006 7:37 pm
by Cheryl Jones
actually i heard somewhere that bats have very good eye sight

So says the National Wildlife Federation
"In addition, bats are not blind and many have excellent vision.":bat:


PostPosted: Nov 27, 2006 7:43 pm
by Teresa
My dad used to do about the same thing--come into my bedroom while I was sleeping and take a picture with the flash. Astonishing, and woke me up, but not necessarily blinding. Bats have OK eyesight--but they can't see at night in the dark any more than we can.

As long as you are taking a photo outside of hibernation season, it likely will startle them, and I wouldn't make a habit of ii in the same place, but hey, if Merlin Tuttle takes photos of bats at night, I doubt if it is fatal. I think I'd keep the flash a reasonable distance away, though. I wouldn't like it if someone photoflashed me from 2 or 3 ft away, would you?

Let's see what tropicalbats has to say.

PostPosted: Nov 27, 2006 7:48 pm
by Darklight
I've photographed a couple of hundred thousand bats (no, really, literally, all at once!) and I don't think the actual flash/strobe affected them much. In Fern Cave, it was really our presence that stirred them up.

Actually taking pictures registered no response as far back as I can remember. Even when photographing solitary bats, I can't recall getting much of a rise out of them.


PostPosted: Nov 27, 2006 8:42 pm
by Ralph E. Powers
In my experience some bats are tolerant of flashes as long as their eyes have been pre-exposed to light (i.e. your headlamp and they're awake). This little fella didn't even register any annoyance or even tried to flitter away or nothing... It depends I guess. Like someone said... as long as it's not habitual and one isn't trying to photograph every-single-bat-in-the-colony... should be okay. I'd imagine the whine of the strobe powering up could be more disturbing than the light.

This is a Townsend Big-Eared Bat somewhere in Utah. :kewl: Image

PostPosted: Nov 28, 2006 10:46 am
by graveleye
thanks for the reply folks... I'm guessing moderation and respect are in line when taking pictures.

PostPosted: Nov 28, 2006 10:52 am
by hunter
Just from observation I'd agree with Darklight. Someone walking through seems to disturb bats more than using a flash.
Looking at Darklight's photo also made me wonder, do bats deal with electric better than carbide?


PostPosted: Nov 29, 2006 1:55 am
by tropicalbats
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 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.


PostPosted: Nov 29, 2006 8:20 am
by Dwight Livingston
Keith - that was very clear answer and interesting. Thanks.

PostPosted: Nov 29, 2006 10:57 am
by Ralph E. Powers
Yes, thank you Keith.
So it is reasonable to say that it's alright (as in not as potentially damaging to the animal) if it's not during hibernation season, that is to say the animal is merely sleeping off it's previous night's activities/feedings during the spring/summer months.
I normally leave bats well enough alone as it is, and admire them from the cave floor and speak softly while in the area. I understand that whispering actually hurts bats ears because of the higher frequency (somehow that doesn't make sense but...).
But on that tact I wondered if the high pitch whine of a strobe powering up will be disturbing to the animals more so because of their sensitive hearing?