What does science tell us about depression in animals?

What does science tell us about depression in animals?

While many stakeholders in the commercial wildlife industry believe that animals respond to their environments based on instincts alone, science has demonstrated that animals can experience depression-like behaviours. This information is not new as an early (and highly unethical) study conducted in the late 1960s by Martin Seligman, an American psychologist, showed that dogs subjected to unavoidable electrical shocks gave up trying to escape their environments after repeated exposure. The phenomenon was termed ‘learned helplessness’ and became an important model for understanding depression in humans and animals. 

What does ‘learned helplessness’ mean?

‘Learned helplessness’ occurs when an animal is repeatedly exposed to stressful situations outside of their control. Eventually these animals cease trying to escape their situations. Sadly, even when escape from long-term and repeated exposure to a stressful situation eventually stops, animals experiencing ‘learned helplessness’ may not even attempt to escape. 

How does this relate to depression in animals?

Although Seligman’s study was extremely cruel and unethical, the concept of ‘learned helplessness’ became an important model for understanding the behavioural responses of people (and animals) to depression. It’s a powerful indication that chronic, uncontrollable stressful situations can lead to severe and lasting behavioural and neurochemical changes. 

‘Learned helplessness’ can be seen in passive behaviour, a lack of motivation, and feelings of pessimism that things will never change for the better. In animals, scientists have found that those who display signs of ‘learned helplessness’ even have altered brain chemistry and behaviours similar to people experiencing depression. 

Do animals in captivity experience depression and learned helplessness?

Science shows that wild animals kept in captivity can experience severe environmental deprivation, a lack of control, and long-term exposure to stress, all of which can lead to depression-like behaviours associated with ‘learned helplessness’, such as the following:

Animals showing signs of depression actually mirror what we see in humans experiencing depression, including neurochemical changes in serotonin (implicated in depression) and cortisol (the stress hormone), and neurological changes in brain function and structure. 

What does depression look like in captive animals?

The general public often miss the signs of depression in animals kept in captivity, but the following are strong indicators that an animal is experiencing chronic stress and ‘learned helplessness’:

Animals kept in captivity show these behaviours because captive environments do not provide mental and physical stimulation, they feel isolated from members of their own species, and because they simply cannot escape their stressful environments. 

What does this mean for the welfare of predators kept in captivity?

Captive facilities are by their very nature artificial environments that confine and restrict an animal’s ability to engage in natural behaviours. For predators, like lions and tigers, one of their most inherent behaviours – hunting – is impeded. They are robbed of their ability to roam their territories, hunt prey, and socialise with their own species in ways that are natural to them. Predators kept in captivity often exhibit signs that their environments are harming their well-being and quality of life. By supporting commercial captive facilities, we are failing to genuinely consider wild animals’ quality of life. Even if overt cruelty and neglect is not occuring in a commercial captive facility, captive predators quietly endure stressful and inadequate conditions from birth to death. One or two negative conditions may not feel harmful to the animal’s overall welfare state, but the cumulative impact over its entire life can turn into serious depression and severely affect a captive animal’s quality of life.  

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Is animal welfare compromised throughout a captive lion’s life – from birth to death?

So far in this campaign, we have been looking at animal sentience and how it underpins the way we understand welfare, and how South Africa’s legislation deals with this. 

In our first Animal Sentience blog, we established that many animals, including predators like lions, are sentient beings and therefore experience a range of feelings, including pleasure, warmth, joy, comfort, excitement, cold, pain, anxiety, distress, boredom, hunger, thirst etc. 

By recognising animal sentience, we highlight the importance of the physical and mental welfare and well-being of animals – terms that more or less mean the same thing. The responsibility for the welfare and well-being of any wild animal in captivity falls squarely onto the owner or caretaker of those animals.

It is important to recognise that many wild animals in captivity cannot fulfill their natural needs, as they would in the wild. For example, predators’ prime survival strategy – hunting – is a large part of their natural makeup that they are not able to perform in captivity.

How do we assess animal welfare and well-being?

To assess the state of an animal’s welfare, the internationally recognised Five Domains Model is often used. This model looks at all aspects of an animal’s functioning – their nutrition, environment, physical health, behaviour, and how all four come together to shape an animal’s mental state. 

What does this mean for South Africa’s commercial captive lion industry?

South Africa’s commercial captive lion industry is widely accused, including by the NSPCA, High-Level Panel and Ministerial Task Team, of lacking adherence to appropriate welfare standards. Over the years, the media has covered multiple stories of severe animal cruelty and neglect of predators and other wild animals kept in captivity facilities for mostly commercial purposes. 

So much necessary attention has been given to these cases of severe animal cruelty and neglect, but is animal welfare compromised in a more systemic way across this exploitative industry?

Are captive facilities, including predator parks and self-proclaimed sanctuaries, also compromising animal welfare and well-being in less obvious ways?

For these questions to be answered, we will use the Five Domains Model to delve into animal welfare and well-being across the many stages of lions’ captive lives by unraveling the complex needs of these wild predators in captivity, and the many ways in which owners fail to provide for those needs. 

Lifecycle of a Captive Lion.
What are the welfare implications of removing lion cubs prematurely from their mother?
Lion cubs are routinely removed from their mothers from hours to days after birth, to be bottle-fed and hand-reared by paying volunteers and visitors, who are inexperienced and unqualified animal caretakers. The cubs are fed cow’s milk or milk replacers lacking essential nutrients, vitamins and antibodies. 

Cubs are generally kept in unsuitable, small and barren enclosures with other cubs of similar ages and sometimes even in mixed species-groups (like lions and tigers together), in the absence of adults of their own kind and the love and safety of their mother. 

These adverse physical conditions lead to feelings of pain, sickness, weakness, nausea, discomfort, fear, anxiety, panic, insecurity, confusion, loneliness and even depression, which in turn severely compromises their overall quality of life. 

 

For example, malnutrition and malnourishment as a result of inadequate milk substitutes can cause severe developmental issues such as rickets, deformed spines, weak immunity to diseases, and stomach problems. These formulas are typically higher in sugar content than the mother’s milk would be, which can cause poor eyesight. On top of all this, volunteers and paying visitors don’t adhere to strict hygiene protocols and appropriate feeding which can cause diarrhea and dehydration in the cubs.

Not only is the food inadequate, but bottle feeding by those who are inexperienced and unqualified means that cubs are at risk of gulping air or too much milk, leading to aspiration pneumonia, colic, and pain. Being handled after feeding means cubs can vomit, and even inhale it back in when fed in the incorrect position. 

Mother lions provide essential physical protection even in the form of bodily heat. Newborn lions are not able to thermoregulate and are at risk of being too cold or too hot, especially when exposed to artificial heat lamps. Just like many of us may have seen in very young puppies and kittens, mothers need to stimulate infants to urinate and defecate. Without this done correctly, cubs may experience urinary blockages, constipation and gut impaction, all of which can lead to death. 

Cubs stay with their prides until the age of two years so they can learn everything they need to survive in the wild. In captivity, especially with cubs being removed from their mothers they often cannot even get enough sleep, especially the beneficial kind known as REM sleep (or Rapid Eye Movement that occurs in deep sleep). Frequent handling and a lack of sleep stunts body growth and mental development. 

What are the welfare implications of petting a lion cub?

Inexperienced and unqualified visitors and volunteers pay for the experience of bottle-feeding so-called “orphaned” lion cubs. They are handled by visitors for up to eight hours per day, during a time when they should be playing with their siblings and mother, resting and sleeping. They are often kept in inappropriate, barren and noisy petting enclosures with extreme restricted choices.

These adverse physical conditions lead to feelings of malaise, exhaustion, physical weakness, poor physical development, fear, anxiety, panic, insecurity, confusion, loneliness, anger and even depression. These negative implications on their mental state severely compromises their overall quality of life.

Once cubs are separated from their mother and moved into cub petting enclosures, their barren environments do not provide opportunities for them to thrive. The lack of age-appropriate movement results in poor muscle development and coordination. Cuddling cubs may seem innocent, but at this stage of their lives, their bones are soft and unfused, heightening the risk of bone fractures through being poorly handled or accidentally dropped, especially when human children are allowed to handle cubs. Think about a lioness carrying her cub in the wild – only slightly off the ground and held carefully by the scruffs of their necks. Visitors and volunteers may turn cubs on their backs, pick them up high off the ground, and hold them in ways that are frightening. 

Without the pride’s dynamics, cubs grow up without an understanding of species-appropriate behaviour. Some cubs may become scared and withdrawn while others might become aggressive and dominate more submissive cubs.

What is the most responsible photo you can take?
The one of a cub you didn’t touch. 
The one of a cub lying safely beside its mother, where it belongs in the wild.
What are the welfare implications of speeding breeding lions in captivity?

To meet the demand for a continuous supply of lion cubs entering the commercial wildlife industry means that breeders ensure the lionesses produce as many offspring as possible in order to optimise their income. These females are used as breeding machines in a process that is often referred to as speed breeding. 

Speed breeding essentially means that every time a lioness has a litter, her cubs are pulled away only hours to days after birth. This ensures that the lioness goes back into oestrus far earlier than she would in the wild and can become pregnant again within weeks. Through speed breeding a captive lioness can have up to four to five times more litters in her lifetime compared to a lioness under natural conditions. 

However, the impact of such frequent pregnancies and giving birth has serious consequences for the lioness’ health. Her physical condition will deteriorate and her mental well-being will suffer due to her body going through the stress of pregnancy and the emotional trauma of her cubs being removed from her again and again. 

Added to the physical stress of pregnancy, captive lions are often fed inadequate diets of broiler chickens, supplemented by some beef, horse or donkey meat when available. Chicken is a non-red meat that lacks essential vitamins, minerals  and protein to sustain the mother and her unborn cubs during these repeated pregnancies.

The mother’s health is further impacted by hormonal imbalances from not being able to nurse her cubs and the damage to her reproductive system due to the unnatural high number of pregnancies. The physical effects, pain and discomfort all take an enormous mental toll on lionesses, leading to fear, anxiety and learned helplessness, or depression.

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