Link: https://aeon.co/essays/ecologys-war-on-invasive-species-isnt-science

The casting of ‘invasives’ as ecological villains has long been backed by scientific and political consensus. Yet as species increasingly move into unfamiliar regions, a favouritism towards natives is growing harder to defend. The traditional approach of trying to stop invasions and eradicate successful invaders isn’t just costly and often ineffective. It may be entirely the wrong approach, if we’re concerned about the environment. While some invasive species are truly harmful and need to be fought, others are a healthy ecological response – they’re part of how the biosphere is adapting to humanity’s environmental impact.

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At present, invasive species are not assessed in the same way as native ones. Placed side by side, these treatments reveal a set of double standards. First, native species are presumed innocent, while alien species are presumed dangerous. Second, we are told to learn to live with the former, while eradication is treated as the default response to the latter. But these assumptions don’t seem to be grounded in data. They function instead as prior judgments that shape how evidence is gathered, interpreted and presented. In this sense, ecological nativism is not a scientific discovery, it’s a rigged result we arrive at because we look only for data that will confirm our prejudices.

A healthy ecosystem is healthy because of the complex web of interactions between its participants. These interactions are called ecological ‘functions’. Bees and butterflies pollinate; pollination is an ecological function. Fungi decompose dead wood; decomposition is a function. Plants produce organic compounds through photosynthesis; biologists call this function ‘primary production’. Ecosystems thrive when these functions are performed by the diversity of organisms and processes within them. The first nativist double standard involves calling a function harmful when an alien species performs it, even though the same function would be seen as beneficial when performed by a native species.

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I'm not denying that wildlife can cause serious harms to ecosystems as well as to human health and livelihoods. For example, in conservation circles recently, I’ve been hearing a lot about a species running rampant in parts of Africa, destroying the crops that subsistence farmers depend on, turning healthy forests into expanses of dust, and threatening to attack people, forcing villagers to hide in their homes when they could otherwise be working and socialising. You might not know about all these harms, but I’m certain you’re familiar with this highly destructive animal: the African elephant.

What are we to do about this menace, which threatens so many people, crops and ecosystems over much of the continent? If I suggested a solution that involved killing off elephants in large numbers, you’d probably be appalled, as you should be. Current thinking in conservation science is that human-wildlife conflict should preferably be solved not through eradicating organisms that come into conflict with humans, but by finding means of coexistence.

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When a harmful species is a native species, like African elephants in Africa, people will go to great lengths to peacefully coexist. When a harmful species is an alien, however, the standard response is to eradicate with prejudice.

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Rather than asking whether pythons prey on native species, we should consider a different question: are pythons keeping their prey species in check in ways that lead to healthier ecosystems?

In otherwords, Invasiveness is an analog measurement taken in context within an ecosystem, not a label that can be applied categorically in a yes/no fashion.

It's about damned time.

That whole "invasive species" thing has always frustrated me.

"Oh no - the invasive species is out-competing the native species!"

Yeah - that's one of the ways by which evolution has always worked. Some species that fills some niche finds itself forced to compete with some "invasive species," and it either adapts or dies out, and either way, nature ends up with a species that better fills that niche.

I can just see conservationists getting ahold of time machines and going back to the moment when the first sea creatures crawled up onto the land and going, "Oh no! An invasive species!" and kicking them back into the water.

No borders for bugs! 😂🐛🐜🪲

Just as nature intended

I can just see conservationists getting ahold of time machines and going back to the moment when the first sea creatures crawled up onto the land and going, “Oh no! An invasive species!” and kicking them back into the water.

I can get behind that tbh.

(Honestly I felt the same even as I was writing it, but I went with it anyway.)

"Invasive species" is a technical ecology term used to describe plants and animals that face no predation in a given environment and have a negative effect on the other species native to that environment. Like many other scientific terms, it was misused by people without the technical understanding.

The crux of your argument is species drift compared to forced mass introduction, but there's a huge difference between them. It's similar to the difference in outcomes that can occur when somebody surfaces after deep diving. Go slow enough, and the systems have an opportunity to acclimate to the changes and respond. Go quickly enough, and things break and start impacting systems around them in a cascade. That's the thing that gets missed every time I see this sentiment.

To be clear (and not having read the article because I know the argument already): the problem with anthropogenic species invasions is they reduce biodiversity in the short to medium term. Yes, sure, "life finds a way", and on the 100m-year horizon everything will have recovered (perhaps on a different trajectory). But not in a timespan relevant to us. And a biosphere with less diversity is going to make things less pleasant and much harder for us, possibly quite badly and quite soon.

The article presumably recommends a more targeted and effective approach to conserving biodiversity. Fair enough if so, but words like "prejudice", "nativist" and "dogma" are not encouraging me (personally) to give it a full hearing.

PS: if the added quotes are representative, and the author did not in fact go full "antiracist" on a topic of science, then credit for that at least. Clearly there are many cases where it makes little sense to push back against a fait accompli (Burmese pythons, cane toads, etc). But in other cases the "native" argument which so triggers the author might prove to be a useful lever for mobilizing useful action.

PPS: upvoted anyway, in the name of debate! Keep 'em coming.

Please read the article, it is Aeon, I have rarely read an Aeon article that didn't make me think differently in an interesting way even if I didn't agree with the thrust of it.

The point isn't to deny the damage invasive species can set off in an ecosystem, the point is to recognize how easy it is to see conservation as a war against invasive species, which is not only bad science it also leads into reductive patterns of thinking that fail to understand that even as an invasive species is intruding upon an ecosystem it is becoming part of that ecosystem in some way. Once the invasive species has intruded, the solution can never be as simple as "delete the new stuff and go back to the old version!", that is how software works not ecosystems. We must grapple with the new reality and begin to understand how our empathy must extend to these creatures invading the ecosystems we love even as we seak to mitigate the processes of damage they can accelerate.

Obviously, it is complicated right? This article doesn't pretend it isn't, so I definitely recommend giving it a read! Aeon articles are kind of my gold standard for brainfood lately, they rarely miss.

Personally I'm bothered by this talk of "empathy". To me, animal welfare is an entirely different subject from biodiversity. And obviously it begs the question: what about empathy for the out-competed native creatures? Empathy can be dangerous here, IMO. For example, feral cats are a major hazard to biodiversity (not to mention their prey). This is an invasion case that is eminently solvable. Except it turns out there are a lot of humans with outsized empathy towards pussycats (see: New Zealand).

You're within your rights to dismiss my points because I refuse to read the article, but I'm certain I've heard all these arguments before (including as you just outlined). Basically it's a calque of the culture war onto science. I'd bet money the word "racist" is in it somewhere, or at least immigration. If the author is suggesting concrete ways to preserve biodiversity, then great. If it's just to wage politics by another means (again: "prejudice", "nativist dogma"), I'll pass.

I did read the article, and I generally agree with you—but I’d add that the most important thing is global biodiversity (or even, the ability to increase global biodiversity on an evolutionary timescale going forward).

An invasive species might have a negligible effect on the biodiversity of the local ecosystem (or even a positive effect, if it’s replacing the functionality of a previously-lost species), but if you add the same species to every similar biome in the world, then each of those locations loses the opportunity to diversify in a different way. (And it increases the odds that a pathogen will adapt to the homogenized ecosystem and decimate every instance around the world simultaneously, with no unaffected ecosystems left to restore lost functionality.)