Same sort of discussion is on another forum, lifted this off it:
I used to work as a field guide and was asked this question a lot by my guests.
This is a very sensitive subject and the only correct answer unfortunately for us photographers is...
Don't take any photo's. (which were not about to do... )
All nocturnal animals are sensitive to bright lights. You can half blind a leapord for a time, which could influence their ability to hunt, although there is all kinds of arguments for and agianst. Diurnal (daytime) animals are even more sensitive to bright lights at night and a sudden flash could blind it at a crucial time and survival could become slightly more difficult for a while.
With this in mind I always preached the following ettiquette...
1. Look at the animal. An elephant can be very dangerous if startled at night. If the animal is dangerous, don't take the shot unless the guide says it's safe.
2. If the animal can be seen during the day then wait for daylight, you'll get a better photo then anyway.
3. A lot of people took photo's of animals 50m away from the vehicle with small point and shoots. If the camera can't handle the shot, rather not take it, as the animal will still be disturbed.
4. Don't take photo's of an animal, which looks directly into the flash. It does hurt their eyes, just think how you would feel if someone did it to you when you didn't expect it. (I actually witnessed a charge from a lion being percipitated because of this)
5. Take the photo in silence. There is nothing worse than a person getting verbally and loudly excited in there attempts to control the lights and people around them.
6. Make sure the guide knows you're serious about photography and station yourself close to him for easy communication and make sure the guide knows what your preffered angles are. In my experience most field guides are photographers themselves and will understand.
7. This is the most important one... Do not, under any circumstances, influence the course of nature with your photography. I had a client who started taking photo's during a lion hunt, dispite my explicit instructions not to. The lion got a fright and aborted the hunt. This might not sound serious, but that lion might have needed that hunt to succeed desperately. Nature exist on a fine balance and I had to restrain myself from dropping him in front of the lion to make up for the interrupeted hunt. He also spoilt the most sought after event for all the guests on the drive. They wanted to throw him to the lions as well.
There is not much to add to this....
: The photos from our trip! Overhere! Feel free to use any of these additional letters to correct the spelling of words found in the above post: a-e-t-n-d-i-o-s-m-l-u-y-h-c