Few people realise that palm kernel is used for animal feed. Hardly any shoppers realise that the milk, beef and bacon they buy may be coming from palm-fed animals, contributing to the demise of iconic wildlife in the world's remaining jungles.
In northern Sumatra, pressure is growing on what's left of the rich jungle heritage, and the conflict between elephants and people is escalating.
This is the last place on Earth where it is possible to see Sumatran elephants, tigers, rhinoceros and orang-utans in one area.
Parts are still relatively untouched - primarily because they are very inaccessible - but swathes of the richest areas, where the remaining wild elephants live, are under serious threat.
The Sumatran elephant is by far the most endangered elephant in the world, but its plight is little known. In Africa, ivory hunters are the big enemy. In Sumatra, poaching is not unknown, but the real enemy is something far less sinister-sounding: palm plantations.
Over the last 20 years, deforestation has been driven chiefly by the expansion of palm-oil plantations. The demand for palm oil in consumer products, and its negative impacts on the environment, is now relatively well-known.
What is less well known is that palm products are being widely used to feed factory-farmed animals. The oil is derived from the reddish pulp of the fruit, but there's more to palm than the oil.
Dig deeper into the fruit and you come across the edible seed or kernel. The industry renders these nuts down into kernel oil and palm kernel meal, or 'cake'. This palm-kernel meal is then transported as a protein source to the feed troughs of industrially reared animals all over the world, but especially in Europe. It can be used to feed all manner of livestock including cattle, sheep, goats, pigs, poultry and even farmed fish.
Deforestation and habitat loss
The rate of deforestation in Sumatra is staggering. Since the turn of the century, 1.2 million hectares of lowland forest and 1.5 million hectares of wetland forest cover have been lost. Half a century ago, more than four-fifths of Indonesia was covered with tropical forests. Now with one of the highest rates of deforestation in the world, less than half of the country's original forests remain.
For Sumatra's elephants, orangutans and tigers, this is bad news: their homeland is literally disappearing under their feet. More than a third of the jungle habitat of the critically endangered Sumatran elephant has gone within just a single elephant generation. As a result, over the last 25 years, entire populations of elephants have disappeared.
Official estimates suggest the critically endangered Sumatran elephant is down to its last 2,500.
I came to Bangkeh, in Sumatra, to learn more about the plight of these elephants and the people who live here. I was feeling dishevelled from long days on the road and hot restless nights. The airline had managed to lose my luggage, I had little more than the clothes I was wearing, and these were now blood-stained from leech bites.
Judging by my stubbly chin, I also badly needed a shave. I didn't have a mirror, but I guessed that it was not a good look.
All the same, it was a thrill to be in Sumatra, the western teardrop island of Indonesia. The country has one of the most biologically and culturally rich landscapes in the world. Its rainforests contain a tenth of the world's known plants, 12% of its mammals and 17% of its birds- an irresistible draw for a wildlife enthusiast like me.
Whither the elephants now?
In Bangkeh, the locals seemed pleased to see us, and to have a chance to tell their story. A house has been raided, and the villagers are scared and frustrated. On the edge of the forest, the side of a simple wooden house had been ripped off. The room, festooned with laundry, was now open to the elements. There was something rather pitiful about the bedraggled clothes. Drying them was now the least of the inhabitants' problems.
The 'culprit' is a Sumatran elephant, probably attracted to the village by the smell of food. This is no isolated incident. Twenty or so elephants are thought to live in the area. With their forest home shrinking fast, they visit more often now, and are getting harder to scare off.
Locals don't want to harm the elephants, but if the government doesn't act, they feel they may have no choice.
The villagers here have turned to using a small company of tamed and trained elephants to help prevent their wild counterparts coming into conflict with people.
All the Sumatran elephants on the patrol are former raiders themselves, captured and trained to help keep their wild brethren where they belong in the forest. The idea is that they police the border between villages, cultivated land and jungle. Where they come across wild herds straying too close to the edge, they push the animals back into uncontested territory using fireworks and the like.
They treated the animals gently, and with respect. Yet I had been dismayed by what I'd heard about the way elephants are trained for the tourist trade - how, whether born in captivity or captured from the wild, their mind, body and spirit are broken to tame them.
As one environmental activist told me: "It ain't pretty." Although I didn't know how these elephants had been trained, and hoped it was gentle, I felt uncomfortable about taking up an invitation from the mahouts to ride, even though clambering through the undergrowth was filthy and uncomfortable.
With every passing day, the patrols are more necessary.
Millions of square miles of industrial monoculture
Dominated by multinational networks based in Asia, Europe and North America, the global palm trade is worth some $42 billion a year. On the face of it, it's an innocuous-sounding business. From the air, the plantations look like giant green carpets. Hard to imagine, then, that these luscious-looking canopies, reminiscent of holiday pictures, could be a source of so much harm.
Sadly, the truth is that they are no better than any other monoculture: plantations made up of mile upon mile of a single species of tree, supported by the usual barrage of herbicides and pesticides, creating a barren landscape.
A single hectare of Sumatran rainforest (an area equivalent to two football pitches) can hold more species of tree than there are native tree species in the whole of the UK. By contrast, palm plantations are just that - palm, and more palm. Once the forest is gone, it's gone.
World production of palm-kernel meal more than doubled to 6.9 million tonnes a year in the decade to 2011. The European Union (EU) is the biggest importer, accounting for around half the world's production in 2012.
By country, the biggest users of palm-kernel meal are the Netherlands, New Zealand, South Korea, Germany, the UK and China. And it's not only palm kernel ending up in livestock feed troughs. According to UK government figures, some 150,000 tonnes of crude palm oil and its derivative was also reported as having been used for animal feed in 2009.
What's the beef with palm?
What I've found is that few people realise that palm kernel is being used for animal feed. Hardly any shoppers realise that the milk, beef and bacon they buy may be coming from palm-fed animals, let alone contributing to the demise of iconic wildlife in the world's remaining jungles.
In Sumatra, the result of this booming industry is to force elephants to venture where no safety-loving wild elephant would roam: the forest edge. The vast majority - 80% - of remaining elephants now live outside designated conservation areas, and unfortunately, they like the same flat lowland terrain as people.
Sumatra's last remaining elephants are now scattered in isolated patches across an island twice as big as the UK. Simple conservation measures protecting piecemeal bits of habitat fall well short of what is needed.
Meanwhile, the palm kernel market is booming. In recent years, demand has soared. The value of Indonesia's kernel trade alone rose tenfold between 1990 and 2013. A ready market for kernel as industrial animal feed adds about a tenth to the income from each palm fruit, offering further encouragement to the growth of the industry.
Right now, we have a vicious circle. The increasing availability of palm-kernel meal, as feed, drives industrial animal farming. In turn, factory farming drives demand for more cheap feed like palm kernel. Vast tracts of land are being lost to monocultures producing fodder for animals, rather than food for people. Among the losers in this equation are Sumatra's dwindling elephants.
The palm industry may claim with some justification that palm kernel is just a by-product of its main game: peddling palm oil. Perhaps better that it feeds animals than that it goes to waste. In addition, it may be difficult to reduce demand for kernel without first reducing demand for palm oil. But that is no excuse for inaction.
In far-flung lands, spectacular species like elephants and tigers are being driven to extinction by our demand for cheap meat piled high - but there is a better way. To help Sumatra's elephants and other iconic wildlife, avoid factory farmed meat and dairy, instead choosing pasture-fed, free range or organic.
Philip Lymbery is chief executive of leading international farm animal welfare organisation, Compassion in World Farming, and Visiting Professor at the University of Winchester.
He played leading roles in many major animal welfare reforms, including Europe-wide bans on veal crates for calves and barren battery cages for laying hens.
Described as one of the food industry's most influential people, he has spearheaded Compassion's engagement work with over 700 food companies worldwide, leading to real improvements in the lives of over three quarters of a billion farm animals every year.
The book: This article is an extract from Dead Zone: Where the Wild Things Were, which explores the links between factory farming and the demise of our iconic wildlife - and what we can do to save it.