73: The Ecology of Fear

It can be easy to compartmentalise science and emotions as being totally separate. However, how we and the creatures around us feel do have an impact on the natural and physical world around us. This week we will be exploring this topic by looking at the ecology of fear, an emotion or response which has many important short and long term repercussions on the behaviour of organisms. As a quick disclaimer, this plog is inspired by a talk from Dr Liana Zanette, a real expert in the ecology of fear, so credit to her where it’s due! Here we’ll be exploring what fear is, why we have it, and some of these long term effects it can have in the animal kingdom. Enjoy!

This week’s topic? Fear (Picture: Loveteamin/CC BY-SA 3.0)

Why we have fear

Fear is super important. It is a response we have had since the dawn of time to help keep us safe, both physically and emotionally. There is many reasons we might feel fear. If a rabid barking dog is sprinting towards us, fear does the important job of informing us that something bad might be about to happen, e.g. us being mauled, and the adrenaline that comes along with fear gives us the extra energy to run for our lives. The same goes for a zebra who notices it is being eyed up by a cheetah.

However, we don’t always see the cheetah or the dog before it’s ready to pounce on us, which is why we also have a fear of potential danger, or the unknown. This is the fear that can, for example, make people afraid of the dark. There’s nothing obvious that could attack us in a dark room, but we also don’t have very good eyesight without light compared to many other creatures, so we can’t be 100% sure we’re safe. Our body prepares and warns us with fear, just in case.

We also have emotional fear, e.g. we might be nervous about giving a talk in front of a big group of people. If the talk goes badly it’s not like the audience is going to pounce on us and kill us. However, the fear of doing the talk wrong and getting rejected by our social group can hurt us emotionally, and a very primal part of our brain may also be reminding us that we survive a lot better with a strong social network. This isn’t completely restricted to humans, many animals can feel jealousy, hurt, rejection, anxiety etc… meaning they can also feel emotional fear too.

So fear helps to warn us that a high-stakes situation is or may be about to happen, and it gets some adrenaline pumping through our system in case a quick response, e.g. fight or flight response, is needed to protect ourselves.  How do we gain these super important fears then?

The zebra prey rightfully has a fear of one of their predators, cheetahs (Picture: Michelle Juma/Wikimedia Commons/ CC BY-SA 4.0)

Learning fear

A caribou being afraid of a wolf is a very logical fear- that caribou has probably seen other members of its herd be hunted by wolves, showing to them that these predators can cause very real harm. That is a learned behaviour, and may be where many fears come from. Perhaps a fear of snakes comes from knowing some are poisonous, so our brain assumed all might poison us to stop us accidentally getting near the wrong one. Perhaps a fear of heights comes from our experience of falling off low stuff and knowing it hurts, meaning in our brains we know that falling of something very high will hurt much much more. Perhaps a fear of spiders comes from those around us, e.g. a family member being terrified of them and passing this fear on to us. After all biologically it makes sense to learn about what is ‘dangerous’ from others so we don’t need to go through the experience of being harmed by it ourselves first. On the other hand people often comment on how when humans first arrived on uninhabited islands like the Galapagos, the wildlife there showed absolutely no fear of the humans, as they had never encountered them before as anything dangerous, or indeed as anything at all!

Some fears can also be based on a single event, and develop into conditions like Post Traumatic Stress Disorder. If someone has been in a situation that has either caused, or very nearly caused, some very notable physical or emotional damage, their primal brain wants to do all it can to protect them from that ever happening again. It becomes extra cautious and can regularly remind them of that fear, or highlight even vaguely connected situations as dangerous to make sure they are ready to respond, just in case. How this manifests itself varies person to person, and animal to animal. It is still a basic survival mechanism but one which may flare up into overdrive to keep you protected from a situation that has been highly distressing.

Walking around in constant fear is stressful however, and isn’t always very helpful. Luckily, the upside to fear being a learned behaviour in many cases, is that it can also be unlearned, especially through habituation or regular exposure to something. As a child the dark cellar downstairs may be the most frightening thing on earth, but as an adult who regularly goes down there to rummage around the boxes, you can get so used to being in the cellar and nothing bad happening to you that you don’t feel unsafe there anymore. Similarly, with birds in the garden, they might first flee in terror every time you come out, but if you are always kind and gentle, never posing a risk to them, they may slowly become less afraid and not fly so far away.

Quite honestly, we’re not entirely sure where all fears come from. Not all are learned or logical, some may even be genetic, but many basic ones seem to be learned as a survival instinct.

Fears, such as a fear of the dark, can often be learned or unlearned (Picture:  Mvlogs96/CC BY-SA 3.0)

Long term effects

We’ve talked quite a lot about humans and fears so far. Now we’re going to head a little deeper into the ecology of fear and how this affects other species. So far we’ve looked at the immediate uses and effects of fear- it can help you fight or run away more effectively if you see danger right there in front of you, as you are on the lookout for it. However, what are some of the long term effects?

Fear can cause a range of changes in behaviour. For example, birds who are aware of a predator being present will eat much less, as they are spending more time watching their backs. This isn’t just when the predator is physically there, but can last for weeks or months after the predator has gone. The birds still check often, just in case. They can also spend less time at their nest in case their presence attracts the predator’s attention and puts the nest in danger. Birds can also do the opposite if a brood parasite is present.

Brood parasites are birds like cuckoos who sneakily lay their eggs in other birds’ nest. The other bird then unknowingly raises the chick, this chick often booting out the others from the nest, meaning a cuckoo is raised with minimal effort from the parents, whilst the other bird loses all it’s chicks and uses all it’s energy unknowingly raising another bird’s chick. As in nature animals generally really want their own offspring to survive, to the point where their whole lives may be geared to this, brood parasitism is a huge danger. In fear of this parasitism then, these birds might spend extra time on their nests to prevent the cuckoo from sneaking in another egg.

Animals can also be clever about learning their fear triggers. For example, animals show different degrees of fear towards different creatures. A wild pig will show no fear to a frog, fear to a big cat, and positive terror towards a human. Actually, extensive studies have found that many animals find humans scarier that other top predators. Even top predators like cougars show greatest fear towards the possibility of a human being around, more than another enemy cougar. Even the sound of human voices will cause many species to flee an area and to start to avoid it in future. Elephants have even started learning the differences in human language, fleeing from the voices of Maasai men who hunt them, but showing less fear around the voices of Maasai women or members of other groups who speak a different language and do not hunt them.

Birds, like this Blue Tit, can adjust their behaviour in response to fear, like changing the amount of time they spend on the nest for fear of attracting predators, or fear of brood parasites sneaking an egg in (Picture: Villy Fink Isaksen/CC BY-SA 4.0)

Fear is a very primal instinct within the animal kingdom, designed to keep a creature aware of danger and hopefully make it cautious enough to keep it safe. Many of the fears are learned, and some can also be unlearned over time. Sometimes they are logical, sometimes a bit more illogical. Fear has all kinds of implications for us humans in our lives, and it is a growing field of research in ecology, where studies are examining many of the long term effects, both positive and negative, that fear can have not only on one animal but it’s family, it’s community, and the other species it shares its habitat with. It’s a very basic emotion, but with complex and wide ranging repercussions on the ecosystems around us.

For more info:

A research paper by Dr Liana Zanette on humans being the scariest predator to many animals can be found here

Music: kongano.com

Title Image: Seena Vinay/CC BY-SA 4.0

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