The zoologist Jordi Casamitjana explains why megafauna, the biggest animals, have had one of the worst deals regarding their relationship with humans.

Yesterday I walked ten miles. 

I did it in London, UK, where I have been living for decades. I don’t drive, and as an ethical vegan, I have been avoiding public transport for distances within an hour’s walk — to minimise the chances of my involuntary contribution to an accidental animal crush. With the pandemic and all, this self-imposed rule has been stretched to about two hours now. 

I walked so much yesterday because a friend of mine wanted to show me something around St. Paul’s Cathedral. “A surprise”, she said. And it was, indeed, a pleasant surprise. In the middle of a square, there was a table with lots of food (seemingly all vegan). Sitting around it, some animals of several species were having what appeared to be a working lunch. There were two empty seats, so my friend and I joined them, and we ate lovely vegan sushi. 

The “Wild Table Of Love” is an amazing super realistic bronze statue which will be in Paternoster Square until May 2023. It is designed by artists Gillie and Marc to encourage people to sit with the animals. Rabbitwoman and Dogman, the internationally beloved hybrid characters they created who have travelled the world spreading messages of love, acceptance, and adventure, play host to the party, and their guest, apart from the humans who may want to join them, are animals of nine threatened species: an African elephant, a giraffe, a hippo, a lion, a rhino, a gorilla, a zebra, a koala, and a tiger. 

There is, of course, a message behind the sculpture: Rabbitwoman and Dogman open their table to the animals as a symbol of love and support, welcoming them into their family and promising to protect them in every way they can. I, on the other hand, imagined a slightly different message. When I was sitting with the animals — representing humanity but also the badgers and foxes shown in the T-shirt I was wearing — I was imagining that this was a working lunch to discuss how can we get to the vegan world sooner. Many animals could have been sitting there. Cows, pigs, sheeps, chickens, and salmons could have been there, but in my mind, those who were on the table were the right ones to be discussing this with. Why? Because they are all wild mammals not created by humans — and therefore I feel they have their ancient wisdom still intact — and because many of them have also been the victims of widespread animal exploitation. Like the other domestic animals, they are also killed for food and fibre, but in addition, to become pieces of furniture or trinkets. And they are also kept captive in zoos for human entertainment. In the wild, their bodies are hunted to extinction, but in zoos, their minds are gradually getting extinguished.

Zoos keep thousands of different species captive, but seven of the table’s guests were one of the biggest they keep. There is a term for “the biggest animals.” It is called “megafauna”, and although some definitions say this means weighing more than 46 Kilograms (100 lb), and others more than 1000 Kilograms (2,205 lb), the definition I prefer is between these two, weighing more than 100 Kilograms (220.5 lb). Belonging to this category are some of the animals who suffer more at the hands of humanity. There are specific reasons why megafauna has one of the worst lives in zoos. And there are also reasons why megafauna is been driven out of extinction at a higher rate than smaller animals. It seems that the deal megafauna has with humans is the worst deal members of the animal kingdom ever had. 

I will tell you why.

The Extinction of the Big

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There have always been animals of all sizes on planet Earth, but the laws of physics and biology would set a limit to how big animals can get. If you get too big, you will need more food, you will be less able to move away from unwanted situations, and you may not be able to have a skeleton strong enough to hold your body. In a competitive natural world, this may mean extinction. If we look at the fossil record, we can see, on average, bigger animals in the past than in the present, because many went too far toward the bigger size to be able to avoid extinction. 

Also, there were periods in the past when being big was easier because the environmental conditions helped. For instance, arthropods, which today comprise bees, beetles, lobsters, crabs, scorpions, spiders, millipedes, and other animals with an external skeleton and articulated limbs, had reached bigger sizes in the Carboniferous period (around 300 million years ago), possibly because the Earth had more oxygen then. 

The leading theory to explain this is that ancient arthropods got big because they benefited from a surplus of oxygen created by an exuberance of plants and algae, but a new study suggests that there might have been too much oxygen (which, believe it or not, is a toxic gas), and bigger animals would be better at keeping it away from crucial cells. That may sound contra intuitive but think about oxygen as the gas that makes fire possible — having a bit of fire in a controlled manner gives you energy, but too much it burns you all over. Arthropods don’t have lungs as mammals do, and they get their oxygen through tracheae spreading through their bodies, which is a system more difficult to control. However, if you are bigger, it may take longer for all the air to reach everywhere, which may be an advantage if the air is dangerously high in Oxygen. 

Then, between 245 and 66 million years ago, many types of dinosaurs evolved, possibly reaching the maximum size that a vertebrate could reach on dry land. The largest dinosaur discovered so far was Argentinosaurusalso the largest land animal ever found who measured from 37 to 40 meters (about 121 to 131 feet), and is estimated to weigh 99 to 110 tons. But, as I mentioned earlier, being too big does not help you to adapt when the environment radically changes, so when a big meteorite fell on Earth about 66 million years ago radically changing the climate of the entire planet, the biggest dinosaurs became extinct. Only the smallest ones survived and became the birds we know today. 

Small shrew-like hairy animals who were living with the dinosaurs also survived, and they evolve into all the mammal orders we know today, including primates. The biggest mammal who has existed is probably the blue whale (Balaenoptera musculus), who we still see today, and is bigger than Argentinosaurus. But it is easier to grow into big sizes in water than on land — as there is no longer the problem of needing big bones to hold the weight. The biggest land mammal we know that ever existed probably was Paraceratherium (related to the modern rhinoceros) who lived between 34 to 28 million years ago and measured 4.8 metres (15.7 feet) in shoulder height and was about 7.4 metres (24.3 feet) in length. Its weight is estimated to have been about 15 to 20 tonnes.

Human Hunters Want Them Big

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By the time we humans started to develop a separate lineage from the other apes sometimes between six and four million years ago, many mammals had reached a considerable size. In fact, most mammals were bigger than those ancestral hominids. But then we started to evolve bigger sizes of both body and brain, and we left Africa expanding into other continents. That was bad news for the megafauna of the planet. Recent research has shown that since humans evolved from the species Homo erectus to today, the size of mammals all over the planet has been getting smaller. The researchers found that over the last 1.5 million years since Homo erectus began to expand beyond Africa, the mean mass of hunted mammals decreased by more than 98% because humans hunted the biggest mammals to extinction.

The research shows that throughout the Pleistocene (the period between 2,580,000 and 11,700 years ago), new human species hunted significantly smaller prey than the preceding ones, suggesting that humans eliminated megafauna throughout the Pleistocene, and when the largest species were depleted the next-largest were targeted. The reason why they chose bigger animals could have been that it may have given them a better return on investment of time and energy, as one successful kill could feed a tribe for a long time. Larger animals are also easier to spot and track down and are bigger targets for the weapons used. Technological advancements might have enabled subsequent humans to hunt smaller species more effectively, as in the past they might have escaped more easily. 

And this phenomenon has continued until today. Until around 20,000 years ago, most mammals were bigger than humans, but since then most have been smaller. When farming began about 12,000 years ago the average mass of mammals was around 30 kilograms (about half a human). The average size has been declining because most of the large mammals went extinct across America and Australia. Humans evolved in Africa, so the large mammals in our home continent had learnt to protect themselves from humans, but the big mammals of other continents had no time to adapt to humanity’s destructive expansion.

It seems that humans are doing to mammals what the big meteorite that fell 66 million years ago did to reptiles…but we are doing it slower. This extinction risk for the largest mammals gets worse by the fact that they have much slower reproduction times than smaller animals, so nature cannot cope with such hunting pressure. If we fail to ban trophy hunting, bushmeat, and wildlife trade, and we do not stop — and reverse via rewilding — wild habitat loss, we are likely to continue the pattern of the past, and the elephants, rhinos, lions, orangs, tigers, giraffes, polar bears, and gorillas will be the ones to go first. 

Collecting Big Animals for Show

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It probably was around 12,000 years ago that humans started doing something to animals they had never done before: keeping them captive for future exploitation. That led to the creation of new animals by controlling the reproduction of the captive animals and selecting who would breed with whom according to desirable features — such as long hair, fatter bellies, less aggression, etc.  The resulting new “unnatural” creatures are what we call today domestic animals.

Some domestic animals were kept captive for food, clothes, milk, eggs, transport or work, but once humanity built the first big civilisations about 7,000 years ago, new purposes for captive animals were created: status and entertainment. With the unequal distribution of power of the new patriarchal mega civilisations, the rich and powerful could now show their wealth by collecting two types of trophies: the bodies of rare dead animals they obtained with trophy hunting, and the bodies of exotic wild animals they force to be kept alive captive in their own private zoological collections.

It did not take that long for the status “showing off” of kings and emperors to be transferred to cities and nations, which were now the ones bragging about having the better hunters and biggest zoos. And as both trophy hunting and zoos have essentially been about parading trophies (and they still are), the bigger the trophy, the better. So, megafauna became both the target of trophy hunters and zoo directors. And in a depressing vicious circle, the bigger the animals they shot and captured, the rarer they became, increasing the depraved “value” of their dead or alive trophies. 

When empires made it possible to travel further and to kill or capture exotic animals from colonised nations on other continents, trophy hunting and zookeeping became even more symbolic of domination. The British Empire of Victorian times became an epitome of this, with a proud aristocracy and Royal family going out trophy hunting through the colonies, and the opening of the influential London Zoo parading animals from all over the world. Today, we still see the same type of people who used to do all this still doing it — although often disguised under a conservation smokescreen.    

The Three Hindrances of Captivity 

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Those wild animals who are kept in captivity in public zoos, private zoological collections, circuses, or as pets, suffer from the same problem, no matter where they are kept, how, and which species they belonged to. I call this problem “the three hindrances of captivity” because three deficiencies can be found in any captive situation of any wild animal. They are the following: 

  1. Reduction of the space the wild animals’ bodies evolved to live in. 
  2. Reduction of the quality and quantity of stimuli the wild animals’ senses evolved to receive. 
  3. Reduction of the choices the wild animals’ brains evolved to make. 

Any captive situation would involve a cage, a chain, a fence, or any other “separation” device that would create an “enclosure” where the animals are kept against their will, and the space they have to roam is always smaller than what their wild counterparts have. Equally, life in captivity is boring and deprived of stimuli, as very little happens in the enclosures other than being fed, being moved around for cleaning, and seeing the same animals or humans again and again. Wild animals kept in captivity for life would have received many fewer stimuli than their counterparts in the wild, and the stimuli they receive often do not come in a form the animal evolved to process and understand. And finally, the decision about what to eat, where to go, or who to mate with, is taken away from the captive animals whose brains now lost part of their natural function. 

Every captive wild animal experience these three hindrances, and if they experience them for life (as happens with over 99% of animals in modern zoos), they will end up causing serious animal welfare problems — including a type of madness some refer to as “zoochosis”. These manifest themselves in animals becoming too lethargic or too active, or showing all sorts of abnormal behaviours (for example, stereotypic behaviour such as pacing, neck twisting, head bobbing, circling, self-mutilating, rocking, etc.).

Despite all the attempts over decades to improve the conditions of captivity and the level of care keepers give to the animals, no zoo has ever managed to avoid these three hindrances — I have inspected over 200 zoos and I can confirm this is the case. Therefore, we can say that the “experiment” of modern zoos (to see if they can be transformed into conservation, education or research centres without making animals suffer) has failed, and the only ethical position is to phase them all out — which is what ethical vegans like myself want. 

All zoo animals suffer the three hindrances, but megafauna suffers one more than the others: the first one. The reduction of the “natural” space is greater for megafauna than for medium size and small animals. How do I know this? Because in the early 2000s, I directly measured it.

Enclosure Size for Zoo Mammals

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When I was a freelance animal welfare consultant in 2003, one of my regular clients, then called Captive Animal’s Protection Society (now called Freedom for Animals) published a scientific paper I wrote titled “Enclosure size in captive wild mammals: A comparison between UK zoological collections and the wild.”

What I did was compare the average enclosure size of a random sample of mammals kept during the years 2000-2001 in a random sample of UK zoos, and the minimum home range of these in the wild. The term “home range” describes the area where, under normal circumstances, a wild animal spends most of its life in the wild. The minimum home range is the minimum area animals would roam during their lives, and it tends to be a fixed value for populations of each species. You can calculate the value for each species by looking at the range of the animals of several populations in the wild of the same species and see how the size varies. This will give you a minimum home range, an average home range, and a maximum home range. In my study, I only used the minimum home range, as a zoo enclosure smaller than it would indicate less space than the animals will need to do what they evolved to do.

I used allometric laws to estimate the home range area, while I measured the enclosure size area with the direct observation from videotaped visits to the zoos (I had recorded most of them myself when I was working for the Born Free Foundation). I used some formulas proven to give a good enough approximation of the minimum home range. To apply such formulas, I only needed to estimate the average size of the animals, because, in terrestrial mammals, research had proven that the minimum home range is proportional to body size (the bigger animals are, the bigger the area their home ranges need to be — to provide them with enough food).

I calculated minimum home ranges and average enclosure sizes of a randomly selected sample of 50 mammal species kept in 51 of the 103 UK zoos randomly selected. This is what I concluded:

  1. In UK zoological collections of the period 2000-2001, the heavier the mammals kept the bigger the difference between the size of their enclosure and the size of their minimum home range.
  2. Mammals kept in UK zoological collections during the period 2000-2001 were confined in enclosures that, on average, had an area 100 times smaller than their minimum home range.
  3. Mammals with a body mass bigger than 100 Kg (Megafauna) kept in UK zoological collections during the period 2000-2001 were confined to enclosures that had an average area 1,000 times smaller than their minimum home range.
  4. The results of this study suggest that if a human mostly living in a small village of about 1 Kilometre square was confined to a space with the same spatial restrictions that wild mammals kept in captivity have in UK zoological collections, this human would be living in a space approximately of the size of a telephone box.

Therefore, the “reduction of space available”, the first hindrance of captivity, was much more pronounced in megafauna. It was ten times worse than the average mammal at the zoo. 

You may say that twenty years have passed since I collected the data from the 103 randomly selected UK zoos for this study (which represented about 25% of the population of zoos at the time), so the situation may have improved now. But that is not the case in any significant way. How do I know that? Because to get to a significant improvement, each of the enclosures of each of the big animals in the zoos should have increased in size by a factor of 1000 — just to get to “the minimum” needed, not the average found in the wild. This does not mean making the size of the zoo 1000 times bigger, but the size of each of their enclosures where they keep elephants, giraffes, rhinos, buffalos, hippos, zebras, tigers, polar bears, gorillas, and the rest of the megafauna 1000 times bigger. Do you know any zoo which has grown that much in size in the last 20 years?

I rest my case.

The Biggest May Suffer More

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If in zoos the biggest animals have much less space than they need to live a normal life, you would expect that the biggest of all captive animals kept there are the ones who would suffer more the consequences of the first hindrance of captivity. This is precisely what we find. Who are the biggest animals kept in captivity? Without any doubt, elephants and orcas. 

Plenty of evidence points toward the fact elephants and whales suffer a great deal in captivity. Their suffering is so obvious now, that even most non-vegans who support the concept of zoos are beginning to accept they should not be kept in captivity anymore. The RSPCA is the largest animal welfare organisation in the UK, but they do not promote veganism or are against zoos. However, they now object to the keeping of elephants in zoos. In 2006, they published a report titled “Live Hard, Die Young: How elephants suffer in zoos.” In it, they wrote, “Elephants in zoos die young. New RSPCA-commissioned research reveals captive elephants in European zoos suffer from a catalogue of inadequate provisions along with poor welfare and early death. The RSPCA has seen no evidence to suggest that European zoos are able to keep elephants satisfactorily long term, and therefore believes they must phase out their elephant populations, with an immediate end to imports and breeding. They must also make immediate, substantial and monitored improvements to welfare standards for elephants currently in their care.”  

The situation has not changed much. In 2022, a new report titled “Elephants in Zoos: A Legacy of Shame” from the Born Free Foundation, backed by numerous high-profile conservation and animal welfare experts, including the naturalist Chris Packham, claimed that 40% of infant elephants die in zoos before the age of five. It also says that “a majority” of elephants in European and Northern American zoos develop and display abnormal behaviours, such as compulsive rocking and swaying “as a consequence of long-term psychological damage from being held in captivity.” There are currently 580 elephants in European zoos, including 49 across the UK.

Experts are now calling for a ban on the keeping of elephants in UK zoos, and it has been reported that new legislation, to be brought in by environment minister Zac Goldsmith, may prohibit the importation of any new elephants and allow the existing population in the UK to die out naturally. Other countries may be getting closer to such a ban. For instance, a new bill has been presented to ban elephant captivity in Canada. On 22nd March 2022, senator Marty Klyne reintroduced in the Canadian Senate Bill S-241, also known as the Jane Goodall Act. If passed, the bill would ban the new captivity of some megafauna, would effectively end the use of exotic animals in roadside zoos, and it would phase out elephant captivity throughout the country. Other nations may already be phasing up elephant captivity without the need to pass any laws. For instance, Argentina has been gradually relocating its population of captive elephants to an elephant sanctuary in neighbouring Brazil. 

Whales Matter

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Orcas are the biggest animals kept captive in aquatic zoos (public aquaria and marine parks), but their minimum home range is much bigger than 1000 times the space they have in captivity. In the wild, orcas can travel about half the length of the entire Grand Canyon in a single day, while in marine theme parks they would have to swim the lengths of their tank more than 4,300 times to cover that distance. While their exact home range size is unknown (the allometric formulas for mammals do not work for marine mammals), they have been documented to swim up to 160 km a day. With such a strong first hindrance of captivity, it is not surprising that Orcas show so many signs of suffering when kept in tanks — as the 2013 documentary Blackfish so clearly showed.

In mid-2021, there were 57 orcas in captivity at sea parks and aquaria throughout the world, 30 of which were captive-born. A third of the world’s captive orcas are in the US — like the famous Orca Lolita kept in Miami Seaquarium. A 2017 study in the journal Archives of Oral Biology found that a quarter of all orcas in captivity in the US have severe tooth damage. While in the wild there are virtually no documented attacks on humans by orcas, in captivity there have been four deaths and numerous incidents of unnatural aggression, likely caused by the captive conditions. The dorsal fin collapse in 80 to 90% of captive male orcas may also be the result of their inability to swim in straight lines when in captivity. At least 170 orcas have died in captivity, not including 30 miscarried or still-born calves.

The good news is that bans on keeping cetaceans (whales and dolphins) in captivity are increasing fast. In the US, California, Hawaii, and North Carolina have local laws banning cetaceans in captivity. The UK has not had them in captivity for decades, Switzerland has banned cetacean captivity (but animals currently held are still allowed), France recently passed a law against breeding cetaceans, it is illegal to keep them in Croatia, and in 2019 Canada banned the captivity of all cetaceans

Now that people begin to understand the problems of elephants and cetaceans kept captive, perhaps they will realise that it is not just them who seem to suffer the most, but all megafauna. 

Another Form of Speciesism

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Being big, no matter if you have legs or fins, it is not a very good deal on a planet where humans think of themselves as being in charge of everything. The sad reality is that if you belong to the megafauna club, you are more likely to be killed or captured by humans, who will parade your body to other humans to show how “superior” they think they are. This is just another form of speciesism, the discrimination against sentient beings because of the group they have been classified into. Whether such a group is non-human, non-white, non-male, non-cisgender, non-heterosexual, non-westerner, non-mammal, non-vertebrate, or non- human-size, the process of discrimination is the same. The oppressors think of themselves as superior, and everyone else belonging to the “other groups” are somehow inferior to them, and therefore they can be discriminated against and exploited for their benefit. 

Megafauna has been discriminated against by supremacist humans from the first day they left Africa with the purpose of conquering the world. Many animals bigger than humans have been chased, injured, killed, captured, forced to work, forced to perform, kept captive, and exploited indiscriminately until they can no longer cope with it (as individuals, as populations, or as species). Humans have built their destructive empires exercising dominion over what they call, arrogantly, “beasts”. They even imagine bigger ones who fly and breathe fire, and invent false legends about how they have dominated them too — the patron Saint of both my past and current homes, Catalonia and England, is Sant George, famous for slaying a dragon that never existed. 

But animals of all sizes suffer in zoos and are hunted for trophies, not just megafauna. Smaller animals may suffer more from the second hindrance of captivity, predators from the third, and the smallest of all suffer a lot in the wild from the use of pesticides. On this planet, if you don’t look like a human, behave like a human, or are about the size of a human, you will not be treated very well by most humans. Most, but not all.

Ethical vegans like myself are anti-speciesists, so we do our best to avoid any exploitation of any sentient being of any species, and to not treat individuals with less respect for belonging to any human-defined category. I care about elephants and orcas, and I have campaigned against zoos, aquaria, circuses with animals, or the keeping of wild animals as pets. I also care about cows, pigs, sheeps, fishes, and chickens, and this is why I don’t eat them. But I also care about the tiny insects who may be crashed by our buses and cars, and consequently, I try to walk as much as I can and pay attention to where I put my feet or I sit. Whether animals can be classed as megafauna or microfauna depending on how bigger or smaller are than us, I don’t want them to be killed or exploited and I will keep trying to find more ways to minimise my blood footprint — which, unfortunately, is not zero yet.

When yesterday, after having walked many miles to avoid hurting any insect, I sat with the elephant, the rhino, the giraffe and the hippo, wearing a T-shirt about respecting foxes and badgers, I felt consistent. When, minutes later, I ate a tasty dish made solely of plants, algae, mushrooms, and bacteria, I felt coherent. 

My philosophy and ethics have given me this peace of mind making my life easy.

Much easier than if I had been born big. 

Jordi Casamitjana
“Originally from Catalonia, but resident in the UK for several decades, Jordi is a vegan zoologist and author, who has been involved in different aspects of animal protection for many years. In addition to scientific research, he has worked mostly as an undercover investigator, animal welfare consultant, and animal protection campaigner. He has been an ethical vegan since 2002, and in 2020 he secured the legal protection of all ethical vegans in Great Britain from discrimination in a landmark employment tribunal case that was discussed all over the world. He is also the author of the book, ‘Ethical Vegan: a personal and political journey to change the world’.