When we think of predators, animals such as lions, sharks, crocodiles and eagles may come to mind.
But there is another predator whose influence stretches across almost every ecosystem on Earth: humans.
Humans hunt animals on land, catch fish from oceans and rivers, trap wildlife and collect animal species for many different purposes. Our impact is so unusual that scientists have sometimes described humans as โsuper-predators.โ
But the relationship between humans and wildlife is more complicated than simply saying that animals are afraid of people.
Research suggests that animals can distinguish between different kinds of human activity. A hunter carrying a weapon may represent a very different threat from a tourist walking along a trail.
And predatorsโincluding humansโcan affect prey without actually catching or killing them.
Sometimes, fear itself can change an ecosystem.
What Is a Predator?
A predator is an organism that hunts, captures and eats another organism.
The animal being hunted is called the prey.
A cheetah chasing a gazelle is a familiar example:
Cheetah โ Predator
Gazelle โ Prey
But predator-prey relationships occur throughout nature.
Spiders catch insects. Owls hunt rodents. Frogs eat smaller animals. Sharks hunt fish and other marine animals.
Predation is therefore not unusual or automatically harmful. It is a natural part of ecosystems and can help influence the numbers, behaviour and distribution of different species.
What Is an Apex Predator?
Some predators occupy particularly powerful positions in food webs.
An apex predator is a predator at or near the top of a food chain that normally has few or no natural predators of its own.
Examples can include tigers, lions, orcas, crocodiles and some large sharks, depending on the ecosystem.
Apex predators can influence much more than the animals they directly eat.
By affecting where prey animals go, when they feed and how they behave, predators can indirectly influence other species and even the structure of an ecosystem.
Why Are Humans Called Super-Predators?
Humans are unusual predators.
Unlike most predators, we can use tools and technology to capture animals in almost every environment. Fishing vessels operate far out at sea, hunters use specialised equipment, and humans transport and trade animal species across enormous distances.
Research into humanity’s predatory behaviour has found that our impact differs significantly from that of many other predators.
A global study published in Science found that human hunters and fishers can kill adult prey at much higher rates than other predators. This is particularly important because adults often make up the reproductive part of animal populations.
Other research examining tens of thousands of vertebrate species found that humans exploit roughly 15,000 species of vertebrates for food, trade, pets, medicine and other purposes.
When researchers compared similar geographic areas, humans were found to exploit up to 300 times more species than comparable non-human predators.
This extraordinary reach is one reason scientists sometimes describe humans as super-predators.
But killing animals is only part of the story.
Are Wild Animals Afraid of Humans?
Oftenโbut not always.
A large analysis led by researchers at the Indian Institute of Science examined decades of research into how wild animals respond to humans.
The researchers found that animals generally showed stronger responses when humans represented a lethal threat, such as hunting, fishing or trapping.
Animals exposed to these threats were more likely to increase vigilance and reduce activities such as feeding.
Responses to non-lethal human activity, including recreation and research, were weaker and much more variable.
That distinction matters.
An animal does not necessarily react to every human as though that person were about to attack it.
Instead, wildlife may assess the level of danger associated with particular human activities and environments.
Predators Don’t Have to Eat Prey to Change Their Behaviour
Imagine an antelope knows that a lion regularly hunts beside a particular water source.
The lion does not need to catch the antelope every day to influence it.
The antelope might:
- avoid the area;
- visit at a different time;
- spend more time watching for danger;
- eat less while it is there; or
- move somewhere it considers safer.
All of those behavioural changes can occur without the lion actually killing the antelope.
Ecologists sometimes describe the pattern of perceived danger across an environment as a landscape of fear.
And those behavioural changes can have consequences far beyond the predator and its prey.
One remarkable experiment involving lizards demonstrates how.
What Happened When Scientists Introduced a New Predator?
Researchers led by Princeton University studied lizard communities on 16 small islands in the Bahamas.
The experiment involved three species:
- curly-tailed lizards (Leiocephalus carinatus) โ the predator;
- brown anoles (Anolis sagrei) โ prey;
- green anoles (Anolis smaragdinus) โ prey.
Without the curly-tailed predator, the two anole species were able to divide their habitat reasonably well.
Green anoles tended to live higher in trees, while brown anoles stayed closer to the ground.
Then researchers introduced curly-tailed lizards to some of the islands.
The brown anoles faced a problem.
Curly-tailed lizards are largely ground-dwelling predators, so brown anoles escaped the danger by moving up into the trees.
That helped them avoid the predator.
But it created another problem.
The trees were already occupied by green anoles.
Escaping a Predator Created a New Competition
Now the brown and green anoles were using more of the same space.
Competition for habitat and food intensified.
After six years of monitoring, researchers found that the presence of curly-tailed predators had destabilised the ability of the two prey species to coexist, and some populations eventually disappeared.
Notice what happened.
The predator’s effect wasn’t simply:
Predator โ eats prey
It was also:
Predator appears โ prey becomes afraid โ prey moves โ competition increases โ ecosystem changes
This is why scientists studying predators need to examine the behaviour of prey, not merely count how many animals predators eat.
Fear Can Change an Ecosystem
The lizard experiment illustrates an important ecological principle.
Predators can influence ecosystems through what scientists sometimes call non-consumptive effectsโeffects that occur because prey respond to the risk of being eaten rather than because they actually are eaten.
Those responses may change:
- where animals live;
- when they become active;
- where they feed;
- how much time they spend feeding;
- which habitats they use; and
- how strongly they compete with other species.
The result can spread through an ecosystem.
A change in where herbivores feed, for example, may eventually affect vegetation. Changes in prey distribution may affect other predators and competitors.
Predator-prey relationships are therefore much more complicated than a simple chase between two animals.
Humans Can Create Landscapes of Fear Too
Humans can produce similar effects.
Where animals associate people with hunting or other lethal threats, they may change their behaviour to reduce the chance of encountering us.
That could mean becoming more vigilant, feeding less, avoiding particular locations or changing when they are active.
But the recent research also gives us an important warning against oversimplification:
not every human presence produces the same response.
Wildlife may react differently to hunters, tourists, researchers, vehicles, settlements or people simply passing through an area.
So calling humans โsuper-predatorsโ does not mean that every person walking through a forest frightens every animal.
The type of human activity matters.
Can Humans Sometimes Create Safe Spaces for Prey?
Here is where predator-prey relationships become even more surprising.
Some animals may sometimes move closer to human activity because their natural predators avoid people.
In such situations, roads, buildings or settlements can appear to provide a kind of refuge from predators.
But this does not necessarily make human environments safe.
Animals approaching roads, for example, may encounter vehicles and other dangers. Human-dominated environments can therefore change the risks animals face rather than simply removing them.
For prey, survival can involve choosing between different kinds of danger.
What Happens When a New Predator Enters an Ecosystem?
The Bahamas experiment also demonstrates why introducing a predator into an ecosystem can have unexpected consequences.
Scientists cannot always predict the outcome simply by asking:
โWhat will this predator eat?โ
They also need to ask:
โHow will the prey respond?โ
A new predator might force prey into different habitats, alter competition between species or change how animals use available resources.
This is one reason introduced predators can be especially disruptive on islands and in other ecosystems where native animals have evolved without them.
The Princeton researchers found that changes in prey behaviour could help determine whether competing species continued to coexist.
Are Humans Replacements for Natural Apex Predators?
Not necessarily.
Calling humans super-predators does not mean human hunters perform the same ecological role as lions, wolves, sharks or other natural apex predators.
In fact, research published in 2026 comparing wildlife communities in southwestern China found that areas dominated by human hunters did not reproduce the ecological effects associated with natural apex predators. The researchers concluded that human hunters were not functional substitutes for the natural predator community they studied.
Humans may therefore be extremely powerful predators while still interacting with ecosystems very differently from natural predators.
Why Predator-Prey Relationships Matter
Predators and prey are connected through much more than eating.
Their interactions can affect animal behaviour, competition, population sizes, habitats and biodiversity.
Understanding these relationships can help scientists predict what might happen when:
- a new predator enters an ecosystem;
- a major predator disappears;
- hunting pressure increases or decreases;
- human development expands into wildlife habitats; or
- conservation programmes attempt to restore predators.
It can also help conservationists recognise something that isn’t always obvious:
an animal does not have to be killed for a predator to change its life.
The possibility of encountering a predator can be enough to change where an animal goes, what it eats and how it interacts with other species.
Humans add another layer of complexity because our influence reaches across so many environments and species.
That is what makes the idea of humans as super-predators so fascinating.
We do not merely remove animals from ecosystems.
Sometimes, simply changing an animal’s perception of danger can begin a chain of effects that spreads much further.
