does a flash causes any health problems for animals?

i would like to used a flash on animals, but i want to do it with responsibility
as animal eyes are often much more lightsensitive (nighthunters) it might causes problems

are there some species where i shouldn't use a flash because of healthproblems?
and which animals do response aggressivly on flash?

I have seen this topic discussed here and on many other forums and have yet to see any believable data that shows any damage to any animal caused by flash photography.

Check out this article in our archives by two animal ophthalmologists:
http://www.naturescapes.net/docs/index. ... nd-animals

thank you for the link
sorry i couldn't find it myself

it is a very good article about this topic
but i found some argumentation questionable. can not agree with this:
"Technically excellent pictures of owls and other animals in their natural environment made at night with flash may, in the end, benefit the species as a result of increased public awareness. In select situations, the use of flash may be justified."

Everyone is entitled to their opinion

The point the author was making, that in the specific case of bringing awareness to a species for preservation purposes, there may be times when it is justifiable as there may be no other way to bring this awareness. Of course your opinion may be different

The word "may" in this context is a subtle way in English, to suggest or ask the question that maybe in some situations it can be justified, it is not intended as a full endorsement.

While photographing Tropical Screech-Owls at night here in my backyard I have noticed that flash does not cause that much of an impact to their hunting habits. I say this because more than a few times while photographing the owl it just dropped from the perch it was and caught a prey, apparently not bothered by me taking pics of it with flash.

Of course, like anything involving wildlife, it should be done with caution and always respecting the animal's routine as much as possible. Photographing them every other night could lead to some impact for sure.

One thing I do believe may cause some negative impact is photographing nest sites (day or night), as you may actually be showing the nest location to predators. This is especially true in the tropics, where nests are less conspicuous exactly for that reason.

i am shure you take care for the animals
but, with all respect, who is gone hold the other 3-5 Photographers away
from doing the same thing in the following days, when you are not there?

and for shure they didn't want to blind the animal too

please do not get me wrong, i do not want to say it is bad to do (sorry for my english)
i myself do a lot of wrong things too. but it is good to know if it is good or bad...
so maybe next time i wouldn't do the bad ones again and again

This topic has been discussed in detail in many different forums. I don't understand all the controversy because the use of flash is one of the few issues that can be fairly evaluated from direct experience. Unlike the ethical debate over the harmful effects of baiting and use of audio calls, where it is hard to evaluate the "harm" caused, one can easily see the direct effect that flash has on the bird. Fill-Flash in daylight may sometimes startle a bird, just like a loud sound or the sudden appearance of a predator or other intruder (i.e stalking photographer). In my experience it usually doesn't. I have used high speed flash at cavity nest sites during daylight for a number of years (where flash is intense enough to overpower ambient light). The flash will often startle the bird initially but they generally quickly adapt and ignore the flash. In any situation, if the bird doesn't adapt, then stop the use of flash.
Flash at night is the area that seems to cause the most concern, and I have no direct experience in this area, but there is a wealth of information in past books and articles on bird photography. Every photography source that I have read, from Eric Hosking, to Stephen Dalton, Joe McDonald, Tom Vezo, and numerous others who have used it extensively, is that flash at night does not adversely affect owls. I find it hard to believe that all these well-known photographers would be untruthful. I have only read of one case where flash caused an owl to be momentarily blinded (it crashed into his blind--which was just a few feet from the nest), and that was an account by Eric Hosking in 1936, when he first started using flash at night. He used a Sashalite flash bulb that had a duration of 1/20 sec (an extremely long flash duration, which of course would only take an adequate photograph of a stationary owl). With high-speed short duration flash, Hosking stated that owls would readily adapt and continue to feed young at the nest as before. So it did not appear to affect their routine behavior of flight, hunting and feeding. He likened the effect of short duration flash to a flash of lightning.
As to the question about the other 3-5 photographers that will follow, I can only ask , "What 3-5 photographers?" I generally won't share cavity nest location with other photographers because just the repeated comings and goings can adversely stress a bird; also I don't know whether they'll be using a blind or how close they'll approach, etc. My ethical standard is no physical harm to the bird or its reproductive success.

so i can use a flash on nighthunting animals too without causing any problem
thank you

When it comes to the use of flash, it's very hard to beat an underwater photographer. Topside flashes (those used in wildlife photograpy, not studio lights) have a guide number in the 60-70 watt/secs range, UW strobes are in the 80-200 range depending on make and model. While I can't locate the article, there was a study done on fish's eyes after shot with these powerful lights. Note, fish do not have eyelids and in general can swim away from the offender/photographer. In over 12 years of photographing reef fishes, I have not seen them shy away from strobe using Underwater Photographer more than it would from just an observing diver. I've shot mating mandarin fish and they go about their business even with a peeping tom!

Sometimes larger animals will move way but that's to move away from me, not the flashes....but then again, when you're faced with a bubble snorting, 6 plus foot long , 200 plus pound critter underwater with 2 flashy antennae and one huge eye sprouting out on either side, you'd tend to move away too! Unless you're a great white shark;-)

Stu

Generally information on this topic is purely speculative, as little empirical research (experiments) has been done.

From a science perspective, the only fair way to evaluate biological response to high powered camera flash is to run a controlled test, flashing an animal at various levels and running cortisol tests.

Ed, you make an interesting point that the animals do often react (be it a flight or fight response). In simplest terms, the animal is responding to a stressor. How much stress it causes, how that stress interacts with the animals overall stress load/threshold, how it impacts behaviors, and so forth are all questions to be asked. Additionally, this all will vary from species to species, and scenario to scenario.

To add to the anecdotal experiences, I shoot snakes and can vouge that camera flash can consistently trigger some venomous snakes to strike on command. You can see where this might be a problem, not necessarily for the snake

From a big picture perspective, something to ponder is the fact that many national parks (in countries outside the U.S.) have already banned the use of flash within the park. An as example, flashing in a national park in Costa Rica will often get you a warning and then a subsequent removal from the premises. This is only a growing trend.

So, as a photographer with interest in using flash, one might instead encourage (or fund)folks at Universities or organizations to do such type of research. Such research often isn't a priority as there are usually bigger fish to fry. But, I think science is the only answer here and continually falling back on anecdotal claims (often from professional photographers / little or no scientific background / a vested interest in using flash to make their living) won't get you too far in the long run.

Milmoejoe makes some really good points. But we have to be careful with where we draw the line as to what is acceptable stess. If any type of photographic technique that raises cortisol levels in the subjects is going to be regulated and possibly outlawed, then there eventually may be few types of photography available (Even stalking a bird causes stress). And all the while, hunters and fisherman are enjoying the outdoors and killing their subjects. And I still believe that it is quite easy to judge the reactions of your subjects to flash. If they resume normal behavior, I don't see a problem. So the types of studies necessary are not whether or not the subjects' cortisol levels raise, but rather, does the action cause physical harm, disrupt its normal routine and adversely affect reproductive success. Animals react to stressors all the time, a potential predator that comes too close; territorial conflicts with others of the same species, other humans enjoying the outdoors, etc..-- but they generally resume normal behavior afterwards.
I think that sometimes people condemn a technique or action (such as flash or the use of audio calls) and the real issue is not the effect of the action, but the cumulative effect of too many people using it in one area and resulting in repeated disturbance of animals that does alter their routine and can cause harm. I think that is probably why some parks disallow the use of flash. In little used areas, it would be ok, but the cumulative effect in high-use areas is potentially harmful.

so it all depends on the amount

i can use it if it is done with care and in limited amount
but there is no information, that a single flash did causes a health problem

Unfortunately, the problem gets caught up in the psychology, not the biology. Flash, live bait, calls, etc. all generate a certain amount of public outrage (often regardless of whether or not they truly pose a risk to the species), which also tends to spread quickly these days via the internet.

I think the bans on flash are a very conservative move to avoid conflict. An "all or nothing" solution, if you will. Smart? Not necessarily. Ideally, best to know if the flash is causing undue stress to the natural inhabitants. Even without the data, a smarter decision might be to take a look at larger cost vs. benefit perspective at flashing vs. not flashing. Just like hunting and fishing- invasive nature photography has its drawbacks, but my rough guestimate says that far more dollars are spent on natural resource recreation than the physical losses from animal exposure to flash. (i.e. Nature photographers bring a lot of money to local economies and really feral cats kill exponentially more migratory birds than camera flashes). I think this is the direction where the aforementioned author of the article(s) was going, in saying that the species may actually cumulatively benefit from exposure to flash, seeing as you- the photographer- are putting the spotlight on a species that 99.9% of folks may never get to see in their lifetime. Quoting Jack Hannah, "You have to crack an egg to make an omelette".

On the other hand, I think we are splitting hairs with this scenario. Some folks are proactive and very concerned, which is fantastic. But, in the bigger scheme of things, obtrusive use of flash is often one just one small characteristic of an overly invasive nature photographer-trespassing, infringing upon wildlife/habitat, collecting, improper animal handling, littering, large-scale baiting (e.g. cans of honey for bears) etc. Flashing is simply a behavior that's easy to detect, target and prohibit, as you mentioned.

janfelix wrote:so it all depends on the amount

i can use it if it is done with care and in limited amount
but there is no information, that a single flash did causes a health problem

sorry for a long response that doesn't answer your question

I would guess yes- you can (and should) use flash responsibly with most birds and mammals. As a herp nerd, keep in mind that flashes generate alot of heat and can kill sensitive frogs/amphibians and also trigger certain venomous snakes to strike at you

thank you

it was my intention to get some advices from the biological point of view
not to start an etic discussion about