Why are Koalas important?

Yesterday I was asked – what do koalas do? How are they important? After all, how can something that just sits in a tree all day be much use to anyone, right? To be fair, most of the time we see koalas, they are sleeping off a heavy meal mixed with the fermented juices of eucalyptus leaves. For a koala, every day must feel like like the after-effects of a drunken Christmas dinner!

I love these questions though, because they are THE MOST IMPORTANT, yet conservationists often hurry over this point rather than tackling the answer head on.

Why? Because all most conservationWhy is animal conservation important? Animal conservation is important, because animals are the only mechanism to create biodiversity, which is the mechanism that creates a habitable planet for humans. Without animals, the energy from today’s plants (algae, trees, flowers etc) will eventually reach the atmosphere and ocean, much of it as carbon. The quantity of this plant-based waste is so More can do, is focus on the imminent extinction of animals and while that’s great motivator in principle, it’s can feel like being a real estate agent in downtown Damascus, trying to sell the empty shells of war-ravaged buildings to would-be buyers.

It’s important though, because what we really want people to buy into, is investment in rebuilding. So, how do we represent the true nature of something that was destroyed long before any of us were born, where there is little or no cultural knowledge or value left to see?

There is a science involved in this and it’s used every day by ecological consultants in evaluating biodiversityWhat is the definition of biodiversity? When we ask, what is the definition of biodiversity? It depends on what we want to do with it. The term is widely and commonly misused, leading to significant misinterpretation of the importance of how animals function on Earth and why they matter a great deal, to human survival. Here I will try to More. Ironically, the approach is too-often used to justify further erosion of values through human development but it can also be a force for positive change.

Instead of measuring the here-and-now, you can look at the past scale, magnitude and intensity of an animal’s ecology and its likely impact on biodiversity–remembering that biodiversity means ecosystem structure, function(Of an ecosystem). A subset of ecosystem processes and structures, where the ecosystem does something that provides an ecosystem service of value to people. More and process, which are all the things that provide human life support. If you don’t frame conservation in terms of our life support, then you’ll just end up back where you were, trying to sell declining infrastructure and dying animals.

Let’s find out why koalas are essential to a habitable Australia

What was the natural occurrence of koalas?

Prior to European settlement, 10 million koalas is probably not a bad estimate of population. Eight million were harvested for fur in just 30 years from 1888. Add all the habitat destruction and continuing declines and there are easily fewer than 1% of the original population left. 

The average home range of a koala is about 1-1.5ha and they eat 200-500g of leaves a day.

#1 The magnitude of koala impact

Let’s say 10 million koalas each occupy 1ha (0.01 km²) = 100,000 km². We know that koalas have complex social structures but their territories don’t overlap very much which means every hectare was largely grazed by a single animal and every individual would have been eating an average of 233 kg of leaves every year. 

#2 The scale of koala impact. 

It turns out that the koala’s entire geographic range covers roughly 1 million km² and that’s 10% of our “magnitude” calculation above … which means pretty well every patch of forest in eastern Australia would have once had a koala living in it, mostly along river corridors. That’s a pretty startling statistic but doesn’t surprise me. However, I think only about a fifth of original forest cover remains today. If we want to rebuild koala populations, we’re going to have to increase forest cover by quite a lot. The good news is, that riparian corridor rehabilitation might help alleviate floods and could offer more safe-haven for wildlife to recover post bushfire.

#3 The intensity of koala impact

Eucalypts produce about 10 tonnes of leaves a year per hectare. A single koala would eat about 233 kg a year, which is about 2.3% of annual leaf production. That’s massive! There are other ways we could assess intensity but this one’s pretty awesome.

#4 The biodiversity processes created by koalas

I could probably write a whole book on this subject if I had the time. Koala behaviour would create a process of nutrientA substance that contains the raw materials for life. At a chemical level, these are contained inside compounds that are absorbed into the body and essential energy-containing molecules are extracted, so that energy can be transformed into other chemical processes that use the energy for living. More transfer(of nutrients) the thing that sets animals apart from plants, is that they can move. Some of the biggest migrations on Earth every day, are the movement of insects like caterpillars, from the stem of a plant to a leaf and back, before turning into butterflies and transferring the energy elsewhere. Large-scale migration of grazing animals and migratory songbirds moves More, amplificationAmplification (of nutrients and energy). Animals consume plants and other animals and in doing so, reintroduce important energy-containing nutrients back into the environment, at even higher concentrations and in patches. Amplification of energy is driven by migration and happens at every scale, from insects moving daily in and out of your vegetable patch, to African wildebeest herds and the seasonal More and concentration on a localised level, scaled up to the entire eastern forests of the continent.

The animals would have been supporting entire trophic pyramidsThe gradual reduction in energy content, increase in body size and reduction in number of animals, that occurs the higher you go up the food chain. At the base of the pyramid are a vast number of high-metabolism, tiny creatures and at the summit, are the top predators. To be stable, the pyramid has to have creatures at all levels. More of birds and insects, as well as contributing nutrientsEnergy and nutrients are the same thing. Plants capture energy from the Sun and store it in chemicals, via the process of photosynthesis. The excess greenery and waste that plants create, contain chemicals that animals can eat, in order to build their own bodies and reproduce. When a chemical is used this way, we call it a nutrient. As we More to the ground around trees and helping diversify flowers and mid-story vegetation.

Large megafaunaThe largest animals that represent the top of the trophic pyramid. These are the final building blocks in ecosystem structures for maximum entropy production. Megafauna can be measured at any spatial scale. The largest animal that ever lived on Earth is the Blue Whale. In a grassland, spiders could be considered megafauna The term is generally reserved for animals larger More always have a disproportionate impact on ecosystem processes. As cultivation grazers, mammals have massive impact on shaping forests, mangroves, seagrass beds and grasslands all over the world. This diversifies the number of species of plant that can occur within a small area, maximising carbon sequestration.

The activity of koalas removing leaves is likely to have created light penetration, resulting in higher rates of tree regeneration after fire –this is what’s been found to be missing after passenger pigeons went extinct in the US. Oak forests aren’t regenerating because of the lack of birds.

Overall, the koala’s impact would have diversified niches for many other animals and birds in all the forest’s three-dimensions, amplifying their effect well beyond the impact of single animals.

#5 The ecosystem services provided by koalas

All of the above ecosystem processes stack up to a monumental impact on soil fertility (and erosion mitigation), clean water, climate mitigation, disease and pest control … in fact almost everything we rely on for a habitable country would have been significantly contributed to by koalas (notwithstanding all the other animals they would share the country with).

Conclusion: we can’t survive without koalas

If we benchmark koala populations to what they were a few decades ago, we underestimate their significance because by about 1930, we’d already killed 90% of them for fur.

Sure, these days we see a koala now and again, so it makes us wonder what role they really play in the current ecology. And we’d be right to assume it’s relatively little, after all, we’ve annihilated most koalas and destroyed much of our own life support ecology that they were also part of.

That is why species recovery is vital and it makes this the biggest challenge today.

Protecting a species at the brink of extinction is worthless, if it adds little benefit to ecosystemsHow ecosystems function An ecosystem is a community of lifeforms that interact in such an optimal way that how ecosystems function best, is when all components (including humans and other animals) can persist and live alongside each other for the longest time possible. Ecosystems are fuelled by the energy created by plants (primary producers) that convert the Sun's heat energy More and becomes a fruitless task of protecting tiny isolated populations from going extinct, at great financial cost.

The question we should be asking now, is not whether koalas matter to ecosystems but whether those life support services they create, matter to our own survival? Can we survive without koalas? If that’s not a question you’ve asked before, then it’s time you took a fresh look at wildlife and what it does for you.

It’s a question of what we lose if we allow koalas to slip into extinction, when they are key to rebuilding a better world. It’s a matter of whether we think that it’s worth rebuilding koala populations so we can restore all of the systems that once existed, where we had cooler and stabler climate, fewer bush fires and floods, clean water and fertile agricultural land.

If that’s what we want, then abundant koala populations is what we are going to need.

I think the answer is pretty obvious, so ask yourself, why is no-one talking about this? Where is this conversation among conservationists? It’s a great question and it’s the one I’m writing about in the book I’m preparing … because it’s among conservation’s greatest failure, to explain why animals matter.

What we need, is to recover numbers similar to what there were before we desecrated populations. We can’t ‘research’ and statistically prove what I’ve just described because the evidence no longer exists, which means we have to use our imaginations and dare to dream a little and realise that if we want a future that’s habitable, animals like koalas matter a lot!