A situation in which one species exploits another – in this case baboons eating human-produced foods – is referred to as commensalism.*  Commensalism is the result of many interacting factors, most notably the ecological flexibility of the species in question (which is high for baboons) and the enabling behaviour of the species being exploited (i.e., our own failure to prevent baboons from getting to our food).  Baboon commensalism begins with increased contact between the two species.  At that point, the onus is on humans to prevent it from escalating.  To prevent commensalism and conflict, we must increase the costs to baboons of seeking human foods and/or reduce the benefits of doing so.

All across Africa, humans enable baboon commensalism by deliberately feeding baboons (thereby reinforcing their perceived association between humans and food), by failing to properly deter them from raiding crops and other human-derived food sources, and by failing to properly manage our waste.  

The following diagram outlines some of the root causes of baboon commensalism and baboon-human conflict.  For details, see the associated text below.

 

Our Behaviour

Destruction of natural habitat

The rapid increase of urban sprawl and our own expanding population on earth has unfortunately resulted in continued destruction of our natural environment.  Consequently, wild animals lose their natural food and water resources, sleeping sites, and ultimately, some or all the environmental resources they need to survive.  In this context, it is inevitable that either these species will go extinct or they must share resources that are now utilised by people.

Habitat fragmentation

It is not only the actual destruction of habitat that has dire ecological consequences. Increasingly, our natural landscape is becoming fragmented. Urban developments, farms, fences and roads are carving our environment into smaller and smaller pockets. These pockets are physically separated from each other and thus there is little or no ecological flow between them.  Put simply, animals cannot easily move between them and are thus stuck in these little pockets.  Small portions of our environment are often not sustainable and are therefore vulnerable to rapid environmental degradation and species extinction.  The smaller the pocket, the more likely baboons are to come into contact with humans and adapt their foraging strategies to incorporate human food resources.

Our use of baboon habitat

As human populations grow, human activity spreads outwards into new areas previously inhabited by no (or few) humans. This occurs in the form of commercial as well as recreational activities. These activities often result in humans coming into contact with wild animals on an intermittent basis, e.g., while fishing or hiking.  Many species simply never get used to this and continue to shirk away from people whenever they see them.  Species like baboons, however, gradually become habituated to the continual movement of people through their habitat and eventually lose their natural fear of people. This natural fear may diminish to a point where baboons will then allow people to approach them and vice versa. Sometimes, and more often than not, people who see baboons under such intermittent circumstances (e.g., while on holiday) actually enjoy this interaction and want to further encourage it. They achieve this by deliberately feeding the baboons! The inevitable outcome of this is that the baboons form an association between people and food, and thus whenever they see people they expect to receive food. Having lost their fear of humans as well, they will resort to taking the food from people even when it is withheld.

 

Our Food

Human food is attractive

Human food is typically more digestible and nutrient-rich than the foods that baboons naturally eat.  It is usually highly processed and thus filled with easily-digestible carbohydrates – thus most of the work is done already and baboons can very easily derive energy and nutrients from it.  Moreover, it usually comes in neat little packages.  For animals that forage for survival, small, already-processed, highly caloric mouthfuls are very attractive!

A matter of simple economics

Many baboons have learned that human foods are reasonably easy to acquire and offer great rewards.  It's far easier to spend ten minutes going through someone's pantry and gobbling up the spoils than to spend several hours foraging in the bush!  Human foods also offer high energy returns. Thus some baboons are making a very practical decision: they opt to spend a short time foraging on human food, gain high energy returns, and thus have ample extra time for resting and socializing. This is not only simple economics – from a baboon’s perspective, it is good economics!

 

Baboon Behaviour

Baboons are incredibly flexible

Baboons are notoriously flexible in their behavior.  They quickly adapt to changing conditions.  They are ‘generalists’ in their foraging, which means they can survive on many very different types and combinations of food resources, as long as they get the nutrients they need.  Their diets differ widely depending on the habitat they live in and the resources available to them.  They are also very flexible behaviorally, with different types of social organization and social behavior depending on environmental conditions.  If one of these changing conditions happens to be increased overlap with humans and the availability of human-produced resources, then baboons will very easily adapt to this new situation and start incorporating human-derived foods into their diet.

Baboons compared to other animals

Most species do not possess the behavioral flexibility that allows them to adapt to human encroachment.  Many species are either highly specialized ecologically, in that they rely on particular types of food resources to survive, or they have an innate fear of humans that does not readily dissipate over time.  These species, faced with destruction of habitat and human intrusion, simply decline in population size and eventually go extinct.  Baboons react in a different way, however: they may even increase in numbers due to higher fertility of females as a result of their higher calorie, nutrient-dense diets obtained from humans.  This outcome does not usually occur, though, mainly because baboon commensalism is usually accompanied by baboons getting killed by humans (either accidentally or deliberately) to a degree that it more than compensates for the baboons' increased fertility.

 

Commensalism and Conflict

Baboon human conflict

Commensalism leads to baboon-human conflict.  Once baboons (1) have lost their fear of humans and (2) have learned to associate humans with food, they will readily take food from any person they come into contact with.  This will occur whether the person wants it or not – and whether they resist or not. These types of interactions can occur at picnic sites in national parks, along highways, or in people’s homes.  Whether it’s your sandwich or your kitchen that you’re trying to protect, this is obviously not the ideal situation!  Conflict ensues, and people generally respond by either doing something to harm the baboons involved or complaining loudly to local authorities that ‘something should be done about the baboons!’

Population expansion

The increasing conversion of natural areas by human activity has resulted in some populations of baboons literally being ring-fenced and trapped by human settlements. These baboons cannot move into other habitats and new baboons are unable to enter these populations. A famous example of this is the Cape Peninsula baboon population, which is cut off from the rest of the country by urban development.

If populations such as these expand in numbers, this decreases the available home range of each troop and the baboons have no alternative but to spill over onto land inhabited by people. This situation can be further exacerbated by the fact that human activity increasingly diminishes the resources in the remaining habitat suitable for baboons.

Unhealthy baboons

Commensalism is not good for baboons: a diet of highly processed human foods leads to the same health problems in baboons that it leads to in humans! One population of baboons that subsisted largely on human-derived food had 21% more body fat and higher serum insulin and cholesterol levels compared to wild-foraging troops.  These are risk factors for both cardiovascular disease and cancer.

 

It is not only baboons

In South Africa, human-baboon conflict has achieved international fame.  This is not surprising: baboons are highly social primates and a species with which we share many traits; our conflicts therefore touch an emotional nerve.  It is worthwhile noting, however, that destruction of habitat and human-wildlife conflict is occurring all the time with a wide variety of species, from lions and great white sharks to hippopotamus and elephants, to pigeons and martial eagles.  In South Africa, the vervet monkeys in some suburbs of Durban can cause as much mayhem as the baboons on the Cape Peninsula.  On a more depressing note, we must acknowledge that there are many more species that have experienced loss of environmental resources as a result of human urban expansion without putting up a fuss.  These species simply disappeared quietly into the night.  This occurred because, unlike baboons, they did not possess the ecological flexibility to adapt to a changing environment.  Thus they simply went extinct.  And nobody noticed – because one species simply dominated the other and there was no overt conflict to resolve.

 

The big picture

In some areas, people are currently experiencing the negative effects of baboons entering human space. In some cases, this has resulted in conflicts that result in frequent harm to the baboons, infrequent harm to people, and sometimes financial loss.

It is important to realize that this is what we are experiencing with baboons right now.  But, some time in the not too distant future, we will have similar experiences with other animals.  This is inevitable because the human population continues to grow at explosive rates and consequently our demand for natural resources continues to increase.

We therefore have a decision to make: either we decide to amend our own behaviour and dramatically decrease the rate at which we destroy our natural heritage, or we acknowledge that at some time in the not too distant future we will be one of the very few large species that roam this planet.

 


*Technically, commensalism describes a situation in which one species derives benefits from exploiting another at no cost to the species being exploited.  However, if baboons exploit human resources at the expense of some aspect of human survival or reproduction, then we would be more correct to use the term "parasitism". 

Content on this page contributed by:

Larissa Swedell

Julian Saunders

Thanks to the following reviewers for improving this page:

Susan Alberts

Shahrina Chowdhury

Angela van Doorn


 

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