Croc kills diver - Dehiwala, Sri Lanka

[Dan]

I read somewhere that that octopus doesn't show its blue rings unless preparing to attack.

I’ve seen many blue-ring octopus in Indonesia. I think they just do that to warn its predators. They would blend with the environment when unsuspecting prey comes by and ambush their prey.

Example:
I was just walking in Pandawa beach, Bali during a low tide, stepping between puddles of water and happened to see one as I looked down to a puddle because there was a little fish swimming in the puddle, then there’s a greenish thing crawling really slow towards the fish. As I squatted to get closer to the fish to take pictures of it, it darted away. Then I noticed the green thing was a tiny blue-ring octopus as it flashed blue rings on all over its body and tentacles when I tried to get closer, to warn me to stay off it, as you see, below.

 

[Skeptic14]

How we behave around large predators is indeed a good question. On land, I am going to be very wary if I am in a place where I might encounter a bear, tiger, lion, mountain lion, etc. It does not have to be a predator. I am going to be very wary with a moose or a bison nearby. I need to be smart enough to know what can happen with a creature like that. I have enough knowledge from education and experience to know this.

As for sharks, the movie Jaws came out long before I considered scuba diving, and it certainly did make me afraid to go in the ocean. As time has gone by, though, education and experience has taught me that I have far less to fear than most people would think. I know, for example, that there are nearly no verified accounts of sharks attacking divers at depth, other than spear hunters with a kill, and those are usually going after the hunter's kill. Every time I have been near a large shark, it swims away. My education and training tells me that I don't have to be quite as wary about them.

So what about crocodiles? My knowledge about them, limited as it is, tells me to treat them as I would lions and tigers and bears. If I knew a large saltwater crocodile had been spotted in the water where I intended to dive, I would not go in. If a large shark were seen, I would get in as soon as possible.

Divers's views toward sharks (myself included) I feel is more based on anecdote vs scientific reason to be less wary of them than land predators.

Specifically for myself, just as you cite, I'm aware that most shark attacks are not at depth. So that gives me perhaps false peace of mind. That and having had shark sightings and encounters on dives that were all positive to this point...

But what is the equivalent with bears/tigers/crocodiles? What situation would be considered being "on the surface" when encountering those other predators and which would be considered "being at depth", and thus what is the statistical breakdown there that is analogous? Is there really something fundamentally different about other predators that we are more wary of encountering than sharks? Or is it something very simple like most shark encounters are with those that don't outsize us nearly as much as the land predators we're analogizing? Or perhaps we (divers) are taking a much bigger chance than we think.

 

[boulderjohn]

Is there really something fundamentally different about other predators that we are more wary of encountering than sharks?

Yes, I believe there is something fundamentally different, and as I said, it is not just predators. Our education tells us what we need to fear and what we don't need to fear. If I ever get to go on a safari, I won't set out to pet a rhino, either.

I believe that in some cases there is innate biological fear at work. I believe we are born with an instinctual fear of snakes created by our ancestors' need to survive in a world with cobras, black mambas, boomslangs, gaboon vipers, etc.

 

[Skeptic14]

Yes, I believe there is something fundamentally different, and as I said, it is not just predators. Our education tells us what we need to fear and what we don't need to fear. If I ever get to go on a safari, I won't set out to pet a rhino, either.

I believe that in some cases there is innate biological fear at work. I believe we are born with an instinctual fear of snakes created by our ancestors' need to survive in a world with cobras, black mambas, boomslangs, gaboon vipers, etc.

Using your example, an innate fear of snakes (which some people don't have... I don't) isn't the result of there being something fundamentally different about them as predators vs blue ringed octopus (poisonous and dangerous aquatic species) but simply that humans encountering snakes is statistically common but that's not the case with the octopus.

 

[boulderjohn]

Using your example, an innate fear of snakes (which some people don't have... I don't) isn't the result of there being something fundamentally different about them as predators vs blue ringed octopus (poisonous and dangerous aquatic species) but simply that humans encountering snakes is statistically common but that's not the case with the octopus.

A couple things to think about.

• I recently saw a show about black mambas. As a newborn works its way out of its shell, it can strike, kill, and eat prey before it is fully out of the shell--no parental training necessary.
• My wife and I were sitting on our deck one afternoon, enjoying the Bambiesque scene before us. A variety of small birds were taking turns on the birdfeeder, while below them on the ground mourning doves, squirrels, and two baby rabbits were poking around the fallen seed débris. Suddenly a small bird flew out of a nearby tree branch and gave two loud calls. Within 2 seconds there was not a bird, squirrel, or rabbit in sight. A few seconds later the hawk arrived, clearly disappointed that all its intended prey had left. Who taught all the animals to obey that warning? Who taught the bird to give that warning?
• We had a house guest from Kenya for a month. Whether it was in our back yard or on walks together, she could sense the presence of snakes, and she was afraid of them, even the harmless garter snakes that inhabit our area. When she stepped into our backyard, she knew where every one of them was hiding.

Call it what you will, I believe humans are like all other animals in that we are born with instincts developed of millions of years of evolution. We can enhance or depress those instincts through experience and education. For example, when I was working at a summer camp and had to become the nature director because of a staffing issue, I had to overcome my innate fear of snakes, and I did overcome it.

Nothing in human evolution gives us an innate fear of the blue ringed octopus. Any fear we have of such animals is a product of education.

 

[drrich2]

Is there really something fundamentally different about other predators that we are more wary of encountering than sharks?

Yes. I agree with BoulderJohn that instinct may well play a role. The angle I'm coming from is observed experience. We've seen shark feeding dives where people have close encounters with tiger sharks. We've seen videos of free divers diving down to, and touching, large great white sharks, and situations where an unanticipated great white showed up on someone's dive, got close, and yet...didn't attack.

For whatever reason, it seems to me large, dangerous land-based predators have a stronger sense of 'personal space.' I can't imagine a park ranger approaching and putting his hand on a wild leopard. Even if he were insane enough to remain calm and attempt it, I don't think the leopard would tolerate it. I doubt trying it with a wild tiger would go well, either. The animal might run off rather than attack, but my point is, I think it would feel threatened or at least antagonized in a way some marine predators don't seem to be.

Look at how untrained wild dolphins sometimes interact with humans. They are tremendously unrelated to sharks, and yet they, too, are sometimes willing to be in close quarters with humans.

What land-based large creatures (predator or dangerous herbivore, like hippos, elephants and cape buffalo) show similar tolerance to have us in their space?

 

[Skeptic14]

A couple things to think about.

• I recently saw a show about black mambas. As a newborn works its way out of its shell, it can strike, kill, and eat prey before it is fully out of the shell--no parental training necessary.
• My wife and I were sitting on our deck one afternoon, enjoying the Bambiesque scene before us. A variety of small birds were taking turns on the birdfeeder, while below them on the ground mourning doves, squirrels, and two baby rabbits were poking around the fallen seed débris. Suddenly a small bird flew out of a nearby tree branch and gave two loud calls. Within 2 seconds there was not a bird, squirrel, or rabbit in sight. A few seconds later the hawk arrived, clearly disappointed that all its intended prey had left. Who taught all the animals to obey that warning? Who taught the bird to give that warning?
• We had a house guest from Kenya for a month. Whether it was in our back yard or on walks together, she could sense the presence of snakes, and she was afraid of them, even the harmless garter snakes that inhabit our area. When she stepped into our backyard, she knew where every one of them was hiding.

Call it what you will, I believe humans are like all other animals in that we are born with instincts developed of millions of years of evolution. We can enhance or depress those instincts through experience and education. For example, when I was working at a summer camp and had to become the nature director because of a staffing issue, I had to overcome my innate fear of snakes, and I did overcome it.

Nothing in human evolution gives us an innate fear of the blue ringed octopus. Any fear we have of such animals is a product of education.

Perhaps you misunderstand my position.

My position is that I'm not aware of any evidence that suggests sharks as predators are fundamentally different from other predators such as bears, crocodiles, etc, despite that divers (a lot) tend to behave or believe them to be different, even personifying them.

Hopefully this isn't confused with the idea that there aren't differences between different predators, there of course are, they're unique species so there will be differences. But specifically from a predatory standpoint is there something fundamentally different about sharks vs say bears. Are they not opportunistic feeders that rely on successfully feeding on other animals?

It of course makes perfect evolutionary sense (hence my previous reply about snakes) that instinct in prey animals exists for predators of common encounter but not for ones that would never be naturally encountered by the prey.

That doesn't mean there is something fundamentally different about the predator that doesn't coexist with the prey, it simply wasn't part of the equation.

People typically appreciate the idea that feeding predators is not good as it modifies the behavior of the predator with humans. So is there some fundamental reason that with sharks this is ok when it isn't with say bears?

That's the question... what evidence exists that shows that sharks are fundamentally different predators so they can be treated differently?

 

[Skeptic14]

Yes. I agree with BoulderJohn that instinct may well play a role. The angle I'm coming from is observed experience. We've seen shark feeding dives where people have close encounters with tiger sharks. We've seen videos of free divers diving down to, and touching, large great white sharks, and situations where an unanticipated great white showed up on someone's dive, got close, and yet...didn't attack.

For whatever reason, it seems to me large, dangerous land-based predators have a stronger sense of 'personal space.' I can't imagine a park ranger approaching and putting his hand on a wild leopard. Even if he were insane enough to remain calm and attempt it, I don't think the leopard would tolerate it. I doubt trying it with a wild tiger would go well, either. The animal might run off rather than attack, but my point is, I think it would feel threatened or at least antagonized in a way some marine predators don't seem to be.

Look at how untrained wild dolphins sometimes interact with humans. They are tremendously unrelated to sharks, and yet they, too, are sometimes willing to be in close quarters with humans.

What land-based large creatures (predator or dangerous herbivore, like hippos, elephants and cape buffalo) show similar tolerance to have us in their space?

Sure, I think personal experiences are what people heavily rely on when it comes to decisions we make.

And statistically, divers are definitely much less likely to have a bad encounter with a shark than folks on the surface.

But I've seen crocodile feedings go fine on youtube. Also seen videos where that wasn't the case.

Similarly, there are grizzly / bison encounters that don't go bad.

There could very well be something to territoriality of land predators vs most/some shark species that are more pelagic and/or roam vs maintaining a small predatory area.

But I think its just as likely that its simply about size.

Average reef shark < 100 lbs, so smaller than average person encountered.
Average bull/lemon/oceanic shark around 200 lbs, so similar size to average person encountered.

Leaving only a few species of shark that are on average considerably larger than a person (tiger/white).

Whereas avg grizzly seems to be around 400lbs, crocodile 300-400, bengal tiger 250-300.

Bison 1k - 3k lbs...

Regarding dolphins, not sure if you're suggesting that aquatic species in general are just nicer or more tolerant? That said, I've had only one encounter while diving with wild dolphin, it was cool, I've also read of them ramming people. And of course with a larger species in the dolphin family, orca, there's some good anecdotes where maybe giving them space would be wise. I think that's more a combo of intelligence and size again.

Intelligence leading to curiosity, and size leading to mostly harmless curiosity.

There very well could be something too territoriality differences on land vs in water, but would that be differences in the species or the environment? You have to be close to things underwater before you can see them... that's not the case on land.

 

[drrich2]

Regarding dolphins, not sure if you're suggesting that aquatic species in general are just nicer or more tolerant?

Despite the obvious point of many small fish darting away from encroaching divers, yes, that's what I'm getting at, as it pertains to large sharks and dolphins. While many sharks tend to avoid humans if not baited in, I cannot imagine getting as close to a wild African leopard as I've been to tiger sharks. And smaller carnivores, let's say a badger, wolverine, coyote or fox, probably wouldn't tolerate a human getting as close as the sand tiger sharks on the deep wrecks out of North Carolina, or the lemon sharks aggregating out of Jupiter, FL, in winter. For that matter, it's often possible to get close to goliath grouper - what wild land creature of similar size lets humans approach?

Even herbivores tend to flee (deer, granted they are hunted), or fights (e.g.: hippos). Wild elephants object to close human approach from what I understand.

Yet people snorkel with whale sharks.

Granted, a sand tiger shark can't curl its lip back and snarl at us the way a leopard can, but still, there seems to be a marked difference in the animal's reaction when a human is in near proximity.

 

[Bob DBF]

That's the question... what evidence exists that shows that sharks are fundamentally different predators so they can be treated differently?

The difference is that sharks have never looked at humans as a food source, and until relatively recently had little interaction with humans. And like other animals, if you know their behaviors, one can usually avoid an incident.

Large land predators, and most wild animals have had centuries of interaction with humans and have been trained over time to avoid humans, for their own good, whether humans were on the menu or not.

Right now the interaction between bears and humans is being renegotiated in California, I don't think it will be good for either, in the long run.