"Don't incur any amount of undue stress on the animal"

I’ve seen this sentiment many times with fellow naturalists - the gist of it, from what I gather, is to not even give the animal the tiniest reason to feel stress resulting from your presence. “Do not approach the animal, do not make any noise, do not try to catch it, hold it, or shine a light at it.” I can totally understand this line of thought, why folks want to practice it, although the ultimate rationale behind it is a bit hazy to me. Simple courtesy? Legitimate biological reason? Perhaps some sense of internalized guilt from being human in an animal’s world?

But I digress. The reason I started this topic is because I’ve been mulling it over and I have some thoughts. Now, full disclaimer, I don’t claim to know the truth behind it all, nor am I particularly knowledgeable about ecology and nature compared to you all. But I see these “no undue stress” naturalists and scientists, and then compare them to other naturalists and scientists who have no qualms with catching/handling herps, trapping mammals, netting birds, or even encouraging anglers to hook fish.

You can imagine the discrepancy I might perceive. There’s no reason to assume either one of these two groups is not passionate or respectful towards animals, yet they have very different approaches when it comes to human/animal interaction. Both are learned and educated and dedicated to the welfare of nature, yet to one group it almost seems like a cardinal sin (no pun intended) to incur any extra stress on the animal than it endures in nature without the presence of man.

The way I see it, I can respect the whole “don’t disturb nature” thing, but the amount of “stress incurred” seems negligible to me. The majority of animals living today survived the K/T event, sometimes even worse mass extinctions, so getting startled or handled briefly by a human shouldn’t be much more of a minor annoyance to them. I get there’s a knowledge factor involved, like the proper way to hold a bird or a frog. But even so, are these mild inconveniences, barring pollution or habitat destruction, really severe enough to affect animals to the point of dire consequences, like a gene pool shift or a localized extinction? And on a smaller scale, are they really that significant?

I’d love to hear all your thoughts. This community always provides great answers and discussion for topics like this.


Two general comments.

First, I don’t think it’s accurate to say “the majority of animals living today survived the K/T event”. Not for the trivlal reason that individual animals die, but because species have really changed and adapted to the (massive) environmental changes since that boundary. Moreover, today’s ecological disruption seems to be on a similar scale, in terms of rate of change per geologically-resolvable time – so I wouldn’t write it off present impacts as small change.

Second, I actually agree that we shouldn’t worry about disturbing wildlife, for many of the reasons you mention. But I also want to throw a major asterisk on that agreement: Other species’ perceptions and needs are different from our own, and it can be easy to overlook behaviors that are catastrophic for other species because they just aren’t salient to us. (Consider the challenges of animal rehab.)

For these reason I think it’s good to err toward minimal impact, even though it’s important to encourage everyone to engage with their natural world.


I think where the same few individual animals are being repeatedly interacted with, such as snowy owls on Southerly irruptions being chased by photographers, or Everglades cuckoos being disrupted many times a day by recordings, you have a bad scene. Both for the animals, and for setting up a social dynamic that’s unpleasant for the other observers.

I’m comfortable attracting moths with a UV light and handling them, though.


From my perspective, this question is kind of getting it backwards. Rather than “why shouldn’t we touch animals? Even if it stresses them, they’ll probably survive” I firmly believe the question should be “What are the cases in which it’s acceptable to disturb an animal?”

This is going to be written from a herpetological perspective, since that’s my experience.

The question you pose conflates a few things- individuals with populations, extant taxa with their ancestors, etc. All extant species have ancestors that survived the K/T extinction. There aren’t any examples of extant species that were around then, and there certainly aren’t any examples of individuals that have. Arguing that an individual should survive a period of stress because its very different ancestor did 65MYA did isn’t a fair comparison, especially because so many other individuals of that ancestor species (and other species at the time) did not.

Furthermore, just because a population might not wink out doesn’t necessarily mean it’s ethical to disturb an individual. Firstly, because you (the royal you, not you in particular) don’t know how many people are visiting that population and “just disturbing one individual.” Secondly, because you may cause an individual to miss a feeding opportunity (as in rattlesnakes in ambush), abandon a nesting site (as in disturbed owls, some snakes), or otherwise alter their behavior in small but impactful ways that, and here’s the important part, you can’t know. Put another way, I believe it is unethical to get an organism to alter its behavior in unpredictable ways for recreation, photos, etc. It’s a kind of externality for the activity possibly paid for by the organism in question. Will it cause an extinction? No, probably not. Is it, in my opinion, a jerk move? Absolutely.

I’ve certainly not always felt this way, nor have I always observed my own advice. Of course context, including taxon, behavior, method of handling, etc. matters.

Here’s a blog post written by a friend of mine on a specific taxon that sort of gets at this issue as well.

This was a little rambling, but I hope it gets at the answer to your question.


Seconding the other answers and would add a detail about ‘undue.’ Undue does not mean zero, it just means what is not necessary. I work in avian physiology. We have to measure, band and draw blood from birds. That is quite a lot of stress, but none of it is undue, as it is necessary for the advancement of the understanding of their stress and stressors. While we do have those large amounts of stress being induced, measures are taken to reduce undue stress, by careful design of methods to reduce stress, not visiting the same individual repeatedly over short periods, during stressful or reproductively/behaviourally significant points, minimising handling time and extent, etc. When you say:

‘naturalists and scientists who have no qualms with catching/handling herps, trapping mammals, netting birds, or even encouraging anglers to hook fish.’

you are referring to those that have a reason for that (or at least the scientist half of the group and many naturalists as well). The difference is if there is no/minimal scientific reasoning for the stress, or the extent of the stress outweighs the benefits. It’s for this reason that ethics committees exist for scientific institutions; they will often turn down scientifically valid studies that simply place ‘undue’ stress on the organisms, that outweigh benefits.


That was a great article, thanks for sharing

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A lot of great answers so far, thank you all

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Very good answers! I wish I hadn’t run out of likes.

I agree 100% here. I used to be much more cavalier about grabbing snakes and flipping (and then appropriately returning) cover objects, but that incurred too many instances of my clearly stressing out an animal with no higher purpose than to get a sweet photo or because holding a snake is awesome. And I don’t think either of those reasons are worth it. I’ve gone from “this snake musk smell is the sign of of a good day” to “what reason did I have to bother a snake so badly that it pooped on me and bit me because it feared for its life?” In the cases of scientific study, I think it might be worth it, but to feed my own ego and garner likes and comments on social media and iNat, I don’t believe it is.


That blog post is fantastic. I’m not a herper so can’t relate, but can speak to my feathery friends. The bird that flies/waddles away when you walk down the beach doesn’t seem that bothered. The second person to walk by them isn’t that big a bother. Not the third either. ‘My dog is fine off the leash. My dog doesn’t catch birds.’

The cumulative effects of dozens/hundreds/thousands of people walking by nesting sites, some with dogs, some with dogs off leash, add up and you have nesting site collapses that not one single person ever touched the bird or came close to them. Piha in Auckland region is a ‘great’ example of a kororа̄ colony that collapsed not due to attacks (primarily not here but dog attacks are common elsewhere), but due to cumulative stress of many small individual stressors.

This article perfectly encapsulates the issue, citing John Cockrem, the leading authority on kororа̄ in Aotearoa NZ, followed by two random beach-goers that have no idea what they are doing, leaving it presented as a debate rather than one objectively true statement and two factually incorrect opinions. Just because you don’t personally see the impact doesn’t mean it isn’t real.


Fantastic answers I totally agree with. Especially the cumulative effects are often underestimated when considering ones personal effect on an individual, which might be important to consider especially in charismatic species like some birds or reptiles and so on.

I have worked with different kinds of animals in the past, including butterflies, amphibia, reptiles and spiders. To reach a certain scientific goal I had to frequenty disturb them, handle them or even remove them from their habitat, so am familiar and ok with this kind of interaction. I also endorse some hands on action while getting kids into nature, e. g. something we simply call “tümpeln” in Germany (from the german word for “pond” = “Tümpel”), which allows kids to explore all the small and fascinating live in a pond, which is amazing to get kids involved!

However, in my private photo-safaris I try to take a different approach. For a very long time I tried not to interact at all with the objects I was photographing (apart form just being present, which of course also has an effect on the individual). I see this changed now a slight bit since using iNat, as there are some infrequent cases in which I turned e.g. a snails shell, as this might show an important feature for determination. But generally, I personally still stick with a limited interaction policy.

In general, for me it has something to do with being a role model. I might feel I know exactly how to handle a certain individual without doing it (and myself) any harm and simply releasing it back into the wild. But someone else feeling stimulated to do the same by watching me or my (photo)results might not have the same expertise but might still want to try. The problem is that it is often very difficult to know, what you don´t know. So even if one might feel that they handle individuals respectfully and with care, one can still do a lot of harm because they might not have enough knowledge to anticipate.

For example, in Germany nowadays there is rising awareness of the Chydrit-funghi, which is a big issue for amphibia populations around the world. The implication is not only that you should not touch a frog or toad without reason, but you should also be aware that you might help spreating deseases between different habitats with your shows and other equiment when moving between promising photo sights in spring. This awarenss might have reached certain nature photographers and amphibia enthusiasts by now, but for sure not everybody knows and acts acordingly. I think it is easier to just be a good rolemodel and show that one does not have to get super close to nature to enjoy it, than to explain why you have the right to interact, while others should not.


I agree with many other answers… If there is a good reason, shared and approved by a community (for example approved studies that contributes to the knowledge of the species and management of ecosystems), it’s ok to put a minimal stress on organisms - keeping it as low as possible. Otherwise it’s better to only look them at a reasonable distance.

For example, I do bird banding, that obviously puts stress on handled birds, but I only do it in approved projects, when there is a chance to get really useful results. I would not approve, for instance, a bird banding project with only metallic bands on endangered raptors, if there will be no chance of recapturing them. Otherwise, when I’m birding for my pleasure, I usually stay on the “no stress at all” side.

The reason, as many other pointed out, is that the sum of many little impacts from 7.5 billions of humans is leading to the 6th mass extinction, and even if main impacts are from other human activities (land use change, climate change, water pollution, etc…), outdoor leisure activities have non neglectable impacts, especially because they often directly impact on the last well-preserved ecosystems and endangered species.


There was a topic with poll about handling herps a while back. I had commented that I used to (handle frogs and toads), but now I don’t- and that’s just because it’s not worth the stress to them. Really, our presence and encroachment into their habitats is already much undue stress, so how could I inflict more on them?

Their ancestors, and our ancestors, survived extinction events. That’s not saying much, and I don’t feel like it should assuage your guilt nor mute your conscience. We have fundamentally changed their present and their future as it is. I think we need to tread lightly wherever we go. I visit some sensitive habitats and I know there’s rare plants /there/, but getting there will be disturbing so I won’t do that.


I agree with lots of the responses here, and want to specifically elaborate on two points that others have mentioned. First, I think it’s important to start from a point of trying to cause the least stress to the organism that you can, and only exceed that when there is some defined benefit. For instance, I’m a scientist that has done many projects that involve activities that are stressful for animals (capture, taking blood samples, measuring, marking, having them run on racetracks, etc.). In all these cases, there’s a defined benefit (increased knowledge of the organism) that has been carefully considered and approved by an institutional committee.
When I’m out for my own enjoyment, I love seeing lizards, but I hardly ever catch them (even though it is a lot of fun to me!). Some perceived benefits that might result in me catching something include documenting a species that hasn’t been known from an area before or an unusual occurrence/aspect of biology. I think another benefit is outreach and education: I might catch an animal to show another person how to handle an animal safely (so that they don’t injure it if they need to catch one in the future) or to help another person become comfortable with an animal. For instance, I don’t really pick up garter snakes if I’m on my own (even though it’s fun)…they don’t need the stress, and I don’t need to stink for the rest of the day! But on a recent walk with my nephews who were a bit leery of snakes and hadn’t touched one before, I did catch a garter snake and let them touch it briefly, hoping that it would help them appreciate future snakes.

I also really echo some of the comments above, that in line with the precautionary principle, we as humans really don’t know how other organisms perceive or experience things. We’re coming from the perspective of our own species, so it’s really tough to intuit how our actions may affect an organism with a very different life history. So I think it’s important to be humble in that we don’t know what the impacts of even small things may be. The example of lots of folks trying to photograph single birds adding up to a big disturbance is a great one, and there are also studies showing the effects of trails with even low usage on nearby organisms. So even short, brief interactions that seem “small” to us as humans can aggregate and have larger impacts on individuals and populations.


I just have a couple of things to add, as the responses so far have been great. The first is that many non human life forms get used to being around people. I go out every day to a path along the Red river. There are birds nesting quite happily just a few meters from the path, which is well used. Some have been nesting in the same place for years. No one really messes around in the bush, but there are many people and dogs.
The second is that most of the concerns expressed so far have been been about vertebrates, perhaps justifiably. I have no idea what kind of stress invertebrates like insects can tolerate. I still try to minimize my contact with them mainly because their lives are short and hard enough without me making things worse. As an aside, we had one of our periodic infestations of canker worms. I quite happily step on them if I get the chance, and took to feeding some to the caterpillar hunter beetles that were also numerous. Partly out of revenge for them denuding my small oak tree. There were millions of them, so I don’t think my activities had much effect on the overall population! In general, though, I think a hands off policy is a good general rule.


That thread was so useful to me recently! I had to handle a toad stuck “Winnie the Pooh style” (but vertically) in through a man-made hole last month, and thanks to that thread I think I did it in the least stressful way possible, i.e., I had gloves on and was actively trying to touch it as little as possible.

Actually, it ended up doing most of the work. While I was trying to figure out how to get it through the hole despite its akimbo elbows and bent knees, I put my gloved hand under its feet, thinking that would take some of the weight off its upper body. That hand below ended up giving it something to push against, so it was able to free itself without me having to tug or push it.


Reference the recent fantastic piece by Ellen Knight on Montana Public Radio’s Field Notes. Listen to the audio (and subscribe to the podcast!) because her reading is delightful.


I did just want to make a point about intertidal snails such as periwinkles. It is true that the intertidal zone in most highly populated areas of the world is in terrible shape already from human influences including too many people trampling in the zone and messing with the organisms that live there.

However, my feeling is that if you do want to photograph a periwinkle snail, and you can’t find a dead empty shell, it is OK to pick a live one up, and turn it this way and that to get the best images, as long as you put it back in a safe damp crevice when you are done.

I say that because periwinkles have to deal every day with the tide going out and coming in, once or twice a day, often accompanied by waves, so in real life they often get pulled off their rock and rolled around; they even get bounced off of rocks. Therefore I feel that it probably does not phase them too much to be picked off their rock and handled gently and briefly by a human.

But please, in general be responsible in the intertidal zone, and try to limit your trampling and other disturbances.

  1. In one study of grouse, human disturbance was associated with a possible increase of >10% energy expenditure. For animals at the edge of their range, already stressed due to lack of food or inappropriate terrain/climate, this can be a significant expenditure that could lead to death by many means, including capture by predators that would not otherwise occur.

  2. Even excluding non-lethal effects (which are possible for particularly sensitive animals!), such as decreasing fat reserves through stress-associated energy expenditure could have significant associated fitness costs, including decreases in mating, brood/litter size, and slower growth rates.

  3. Just because stress effects on animals may seem negligible from your perspective doesn’t mean they are not. This is why, at least in the U.S., handling is regulated in terms of ‘take’ since stress does impact wild species’ fitness and population viability. Imagine if a creature 10-1000 times your size picked you up while you were out on a hike or eating lunch?

3.1) 50% of surveyed outdoor recreationists believed they had NO impact on wildlife, even though this is demonstrably not the case.

  1. Ignoring all these effects, amphibians can be impacted by spread of spread of, for example, of deadly chytrid fungus, and we can even be impacted by handling of lizards and pangolins by nasty microbes like salmonella.

I personally have handled endangered and non-protected animal species in educational context with a permit holder, and generally avoid or reduce handling species as much as possible and try to balance that with documenting animals. As I have learned more about the effects of human-induced stress on animals by handling/pursuit, I now lean more and more toward reducing handling as much as possible and settling for lower quality pictures over stressing the animal.

Since hiking near animals can disturb them, it’s a curious question to ask whether hiking near an animal (again different animals have wildly different responses to human disturbance/handling) has an additive impact to handling them, or whether they’re on the same scale…

It’s a very interesting topic you’ve brought up, and I think it is a constructive conversation to have! Recreation ecology for example is a field I didn’t know about until some google scholar searches related to your post!

Grouse flushing and energy expenditure: https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/14-1141.1

Recreation impacts on wildlife: https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/1051-0761(2003)13[951%3AWRTRAA]2.0.CO%3B2


No matter how we look at it: Handling and/or intruding induce stress and derail them from their activity (resulting in energy waste) at the time of intrusion. There’s a good science literature on the topic (I’ll go back to this thread and list a few soon).

Indeed, the question is more “when is it acceptable to disrupt”. This is also one of the questions that we are looking at studying and developing resources for at the Citizen Science Association Ethics Working Group - https://www.citizenscience.org/get-involved/working-groups/ethics-working-group/ (I am a co-chair of this group).

Meanwhile, going in the field to take snaps of critters to get them on iNat ideally would amount to having to follow the same rules as one would if they were doing conservation fieldwork. That also means justifying the rational for the intrusion and clearly explaining the direct benefit for the species.
Here’s our Field Essentials for those interested > https://www.earthwiseaware.org/prepare/conservation-fieldwork-essentials/