Tag Archives: Trophic Cascades

Big Players

There’s a lot of talk about growing inequality, and often we’re confronted with the idea that this is all just natural. Shakespeare said it best, as usual. In Pericles:

Third Fisherman: Master, I marvel how the fishes live in the sea.

First Fisherman: Why, as men do a-land; the great ones eat up the little ones; I can compare our rich misers to nothing so fitly as to a whale; a’ plays and tumbles, driving the poor fry before him, and at last devours them all at a mouthful.

Killer Whale, Matthew Allen (CC)
Killer Whale, Matthew Allen (CC)

Recently I read Bill McKibben’s review of Dark Money, the new book about the Koch brothers. It offers a sober view into the lives and deeds of men of incredible greed and selfishness; men with a totalising determination to treat the whole world – social, environmental, cultural – as a standing reserve which they and their billionaire cronies can devour or discard at will. They are completely unlike whales. Their impacts are disastrous. The Koch brothers are living proof that evil is indeed alive and well, and that it plays nauseating games with U.S. and world politics.

Here in Australia, too, we are enmeshed in systems in which big fish, the wealthy bullies, rise to the top. We are witnessing the abject failure of many key politicians to take action on the urgent environmental and social justice issues that matter for the future of life on Earth. And so I am all the more grateful for the strong moral leaders we do have. Phillip Adams hosted a great panel recently with three articulate, passionate men: Bob Brown, Julian Burnside and Kerry O’Brien. Bob Brown was for many years the leader of the Greens Party in Australia; while guiding one of the west’s first and most successful Greens parties, he became, and is today, an inspiration to the nation and the world. He is breath-takingly honest, and in this recent panel discussion he excoriated the system of powerful lobbyists, describing many current politicians as ‘venal, strong, aggressive people who do what the big money wants them to do’.

Marionettes, Priit Tammets (CC)
Marionettes, Priit Tammets (CC)

Big money, big players, big politics: it all seems to fit, and from a tooth-and-claw vision of the world around us, it could all seem perfectly natural. Recent studies in ecology tell quite a different story, though. Outside the toxic domain of human avarice, living beings are inter-entangled in fascinatingly functional ecological circuits.

Take wolves, for example. There is a perception that wolves and other top predators will have a detrimental impact on other species by the very fact of their food consumption. Recent research, however, is showing a far more interesting story of direct and indirect impacts that work their way through an ecosystem in flows (trophic cascades) that are extremely beneficial.

Wolf in Yellowstone, Oregon State University (CC)
Wolf in Yellowstone, Oregon State University (CC)

Top order predators like wolves are key ecological regulators. The effects of their predation are felt all through the system among other animals, plants, and even land forms. The most accessible study concerns wolves in Yellowstone National Park. Here the re-introduction of wolves impacted first to regulate numerous animal populations, including elk. As the elk were forced to move into marginal areas where they were less exposed to wolves, the river vegetation was able to regenerate. As erosion lessened, the rivers stabilised, and species like beavers and birds were able to return. Beavers are notable for altering river flow to produce a diversity of habitats that are beneficial to many species of mammals, fish, and birds. And so it went. The wolves were few in number; they regulate themselves as well as others, and the whole system was changed in the direction of greater functionality.

These top predators brought about trophic cascades of diversity and stability.

Yellowstone by HikrChick (CC)
Yellowstone by HikrChick (CC)

Top predators are keystone species: the term concerns relationality and connectivity. A keystone species is one with a greater impact on its ecological community than would be expected given its abundance. Across the deep time of ecological relations these impacts have become mostly beneficial. All top predators are keystone species, but not all keystone species are top predators. This is to say that there are many keystone species whose impacts are large, but who are not big charismatic carnivores like wolves or killer whales.

The wonderfully insightful scientist Stephan Harding explains: ‘You never know who the big players are in the wild world.’

Dung Beetle, by Camilo Hdo (CC)
Dung Beetle, by Camilo Hdo (CC)

Harding gives the example of dung beetles in the Amazon forest. These seemingly insignificant creatures are critically significant for the whole forest. Before, when there was greater functionality, they killed off parasites, buried seeds, and facilitated quick and efficient recycling of nutrients. In forest fragments, where the connectivities are coming apart, there is less dung because there are fewer animals. Less dung means fewer dung beetles (fewer in number and fewer in species). There have been extinctions, and the reasons include lack of good quality mates, lack of good quality habitat, and changing micro-climates. The result is that remaining forest fragments are losing their ecological health: more diseases, fewer nutrients, seeds unable to germinate. Harding concludes: ‘Seemingly insignificant, the dung beetles of the Amazon are major players in their ecological community.’ One loss leads to another, leading to more: this is the downward spiral, the loss of vitality, the extinction cascade. It  is happening all over the world.

Amazon forest by Dams999 (CC)
Amazon forest , Dams999 (CC)

Among the many lessons to be gained from thinking with dung beetles, consider this: to see any living being is to know that there is a story involving others, and that behind them are still more stories. To see the luminous beauty of a forest is to see the work of many others, including insects. Indeed, every vibrant living being and biotic community is enmeshed in looping, entangled benefits, in cascades of flowing life. From a keystone point of view, many big players may barely be visible in themselves, and are best seen through the lens of the wider community whose health tells of their activity.

Australians will soon be heading into a federal election, and the U.S. will have one next year. I would love to walk into the polling booth and cast my vote for dung beetles. I am, of course, attracted to the metaphorical dimension of this fantasy. There is an awful lot of shit in political life, more than enough for an army of insect removalists.

Dung beetle 'debate', Jochen Smolka (CC)
Dung beetle ‘debate’, Jochen Smolka (CC)

More seriously, though, I would vote for beetles because I would love to vote for forests. Indeed, each biotic community has its species and relationships: I would love to vote for the giant triton snails that eat the crown-of-thorns starfish that damage the Great Barrier Reef; I would love to vote for those great Australian regulators, the dingoes; really, I would love to vote in any and every way for the future of life on Earth. Good votes, like good ecological actions, are complex, as Aldo Leopold told us long ago: ‘A thing is right when it tends to preserve the integrity, stability and beauty of the biotic community. It is wrong when it tends otherwise.’

There are a lot of bullies who think they’re big players, and they are very good at what they do, which is to wreck things. They have packed huge amounts of destruction into a very short time frame. They are spatially expansive: the cascades of destruction go everywhere. And yet the truth of deep ecological time remains: the wild world is greater than politics, and the big keystone players are doing their best to keep Earth vibrant and dynamic. Long may they live!

© Deborah Bird Rose (2016)

Resources:

The quote from Pericles is found online (here).

Bill McKibben’s review of Dark Money: The Hidden History of the Billionaires Behind the Rise of the Radical Right by Jane Meyer can be read online (here).

Philip Adams on Radio National, Late Night Live, ‘Advance Australia Where?’ (listen here).

The quote from Stephen Harding is in his article: ‘Gaia and Biodiversity’ in Gaia in Turmoil: Climate Change, Biodepletion, and Earth Ethics in an Age of Crisis. E. Crist and H. B. Rinker.

For more on top order predators, see the excellent article by Ripple and colleagues (view here). I discussed some of these issue in earlier essays relating to Australian dingoes, for example, ‘Partnership ‘Rewilding with Dingoes’ (visit here). The Yellowstone video, ‘How Wolves Change Rivers’, is terrific (view here). For more on dingoes as top predators, see the essay ‘Apologising to Dingoes’ (view here).

To watch a giant triton snail eating a crown-of-thorns starfish, view here.

Partnership Rewilding with Predators

Elk near Jackson Hole, Photo: Dave Rose
Elk near Jackson Hole,
Photo: Dave Rose

My father, Dave Rose, was fascinated with the elk that came down out of Yellowstone National Park during the winter months. He took us kids to Jackson Hole to see them, and he persuaded the guy with the hay to let us ride on the trailer while he went through the herd dumping fodder. Dad took slides (and more slides). Sometimes it seemed as if every slide show was all about elk!

Only much later did I learn that the National Elk Refuge was founded in 1912 by local ranchers who were concerned that this great herd might go extinct. Its migration routes were disrupted by ranches and the town.  Conflict between ranchers and elk over hay led to killing, and there was mass starvation.

The establishment of a winter refuge adjacent to Yellowstone, with funds for fodder, was an early action in America’s long and often odd conservation movement. For almost one hundred years wolves were persecuted. Herbivores were hunted. Still today at the National Elk Refuge, ‘both bison and elk populations are managed through refuge hunt programs. Permits specific to each hunt are required and are obtained online or through the Wyoming Game & Fish Department.’

When we went there all those years ago, it was pretty easy to see that this great migratory herd had nowhere to go. Problem and solution seemed pretty clear. But if Dad had read Aldo Leopold’s essay ‘Thinking Like a Mountain’ he might have suspected that there was more to the story. Leopold’s brief, influential essay starts with him killing a wolf, as people did in those days, and then working through the implications of predator loss, overabundance of deer, stripped vegetation, and barren ground.

American wolves in captivity
American wolves in captivity

For centuries mainstream European-origin culture has feared, despised, and sought to annihilate wolves and other predators. The outcome, if one can use such neutral term to describe the result of all this suffering, has been extinctions and extirpations. If Dad had asked about wolves, he would have come upon a story of vicious, cruel persecution that would have deeply saddened his kind and generous heart.

As if in counterpoint to all the death work that has gone into efforts to eradicate wolves, conservation biologists are discovering that the top carnivores have ecological roles that benefit numerous species of flora and fauna. This is counter-intuitive thinking for western peoples, but it is actually integral to indigenous peoples in many parts of the world. The novel Wolf Totem by Jiang Rong tells the story in the context of Mongolia: kill the wolves and you kill the grazing lands, and so you kill the herding way of life.

‘Trophic cascade’ is the scientific term for ecological processes that ripple from one species through others, and through whole ecosystems.

This process has been documented with the re-introduction of wolves into Yellowstone National Park after a seventy year absence. The consequences are completely stunning. A recent video narrated by George Monbiot tells the story in words and images (view here). It is helpful to know that Monbiot uses the word ‘deer’ where Americans would use the word ‘elk’ for the species Cervus elaphus. I don’t want to spoil the drama of the video, so I’ll just make the point that a trophic cascade starting with a top predator ripples through other animal species, plant species, and ultimately even through the physical geography of their ecosystem.

Furlined/Creative Commons
Furlined/Creative Commons

The re-introduction of wolves into Yellowstone is an example of the new thinking that is often called ‘rewilding’. It addresses ecosystem restoration on a large scale; there is no attempt at retrieving primeval ‘wilderness’ – that would be impossible, and if it were possible it would be counterproductive. Rather, rewilding aims to let ecological processes start up again.

The development of rewilding programs in the USA depends on three key strategies: cores, corridors and carnivores. The carnivores are the first key, as Monbiot narrates in the Yellowstone video. If they are healthy, the benefits flow on through the system.

The second key, then, recognises that the top predators require adequate range to sustain themselves across generations. The third key is corridors; it recognises the fact cores can become death traps unless the animals can move. This is so genetically, and equally because ecosystems and climate always offer the unexpected. With climate change, even more unexpected changes are (paradoxically) expected to occur. Animals need the versatility and flexibility in order to be able to respond to change.

Carnivores with ample area and ample connectivity will regulate ecosystems in ways that achieve complexity, diversity, and resilience.

So far, so good, but now the news turns alarming. An extremely important recent publication addresses these issues in the context of climate change and the accelerating extinction event now underway. A great number of the large carnivores that ecosystems need are themselves vulnerable to extinction or local extirpation. The authors state that in light of all the recent evidence ‘alongside climate change, eliminating large carnivores is one of the most significant anthropogenic impacts on nature.’

Photo: John Murray
Photo: John Murray

A good section of the study is dedicated to dingoes, and it summarises the work of Arian Wallach and the other dingo scientists whose work last year was awarded the Eureka Prize. Their conclusion: ‘Overall, the suppression of dingo has probably contributed to the endangerment and extinction of small marsupials and rodents over much of the continent.’ It has also enabled the expansion of a range of invasive species over much of the continent.

The biggest threat to large carnivores is the human species. Finding ways of co-existence is therefore absolutely crucial. Not only is the work that carnivores do ‘underappreciated’ (the authors’ words); in many areas, as is well known, predators are actively persecuted. Many pastoralists have formed the view that livestock and predators are incompatible. Having set up an ‘us or them’ opposition, they destroy the predators.

Dingo Barrier Fence
Dingo Barrier Fence

Here in Australia the conflict is between cattle and sheep farmers on the one hand, and dingoes on the other. I wish they would all read Wolf Totem, but that seems unlikely. Perhaps they will listen to the recent  Bush Telegraph radio report ‘Could dingoes actually help farmers?’ (listen here) The program starts with a fascinating interview with Lyn Watson of the Dingo Discovery Centre speaking about dingo physiology and behaviour. It concludes with Arian Wallach, the dingo research scientist and one of the authors of the influential study of carnivores and climate change. She carries out research on Evelyn Downs Station, a working cattle station (ranch) that is one of the few predator-friendly ranches in Australia.

In the radio interview Arian reminds listeners that dingoes are top predators here in Australia: ‘ …  the health of the ecosystemits biodiversity, its productivity, the condition of it’s soil, the rivers, the endangered speciesare all tightly linked up with the dingo.’ She then very precisely changes the story from ‘us vs them’ (pastoralists vs. dingoes) to interconnection. Rather than barriers, there are connections. Cattle and sheep need biodiversity, dingos sustain biodiversity, therefore pastoralists, livestock and dingoes are all interconnected and are, in effect, on the same side.

Cattle and Dingoes at Evelyn Downs (A. Wallach)
Cattle and Dingoes at Evelyn Downs (A. Wallach)

Arian and Lyn also discuss the problems that arise when dingo ‘control’ (poison, trapping, shooting) creates homeless, unsocialised creatures who are effectively out-of-control. It is a truly vicious circle, and one of our great challenges is how to break the cycle of violence without destroying either pastoralists, or livestock, or dingoes.

To return to partnership rewilding, therefore, I see hope in the idea that the best thing we humans can do for the earth at this time is to work in alliance with other creatures whose lives regulate, pollinate, and otherwise sustain flourishing ecosystems. In relation to flying-foxes I proposed the establishment of vast corridors or networks of flowering trees. ‘Rewilding’ the open savannah woodlands would enable flying-foxes to sustain themselves and continue their work of pollination. Those same corridors could also be habitat for dingoes and many other creatures, and as core areas are maintained, and more corridors are established, the country can become criss-crossed with edges and zones of co-existence.

Life on earth is not ours to destroy, and nor is it ours to engineer solely for ourselves.

Partnership Rewilding acknowledges and works with interconnections. At this time, most ecosystems are massively perturbed and there is a huge role for humans in working to re-establish favourable conditions. The ethics of multi-species alliances thus have several sides. Humans may at times be active partners, and at times may simply need to get out of the way so that others can do the work they are so beautifully evolved to do.

© Deborah Bird Rose (2014)

Postscript: Arian Wallach has just published and excellent article in ‘The Conservation’ (read here)

Her recent interview on Freedom of Species is also relevant and insightful. (listen here)

Resources:

Aldo Leopold’s essay is available online: http://nctc.fws.gov/resources/knowledge-resources/wildread/thinking-like-a-mountain.pdf

The horror of the violence against wolves is conveyed, along with much else, by Barry Lopez in his great book Of Wolves and Men.

Mongolian herders’ relationships with wolves are analysed in Natasha Fijn’s ethnography Living with Herds: Human-Animal Coexistence in Mongolia. She is a terrific film-maker as well, and films from her Mongolian experience are also available (view here).

Acknowledgements: Thanks to Ray Pierotti, author of Indigenous Knowledge, Ecology, and Evolutionary Biology, for the wolf photos and for clarification of the elk/deer nomenclature.