For the general public they may not see the ramifications of invasive species. For example, I work in the middle of a wildlife refuge. Folks come there and see the osprey, pelicans, seagulls, and an abundance of flowers. The impression they may get is that all is fine in this corner of Southern California.
Yet the island is completely overrun by invasive ants from Argentina. In the ten years that I've been there, I've never seen a native ant. Recent science confirms that the Argentine ants push out the native ants. When I go to the mountains, the landscape can be abuzz with native carpenter, sweat, and mason bees, bumblebees too! Although I see these creatures from time to time at my worksite, it's mostly populated by European honeybees.
About half of the flowers folks see at the refuge are invasive iceplant from South Africa and daisies from Europe. If we didn't push them back, they would take over the island.
In the meantime, native plants and animals are evolving to adapt to the presence of the invasives. The Argentine ants spread parasites and disease for almost all the native plants, placing evolutionary pressure on them.
And people just get used to invasive species and think of them as natural. The vistas of California, with the tan hillsides is said to be iconic, views seen in thousands of Hollywood movies. Those tan hillsides are covered with invasive European grasses.
I will never get all the Japanese honeysuckle and Russian privet removed from our woods but that doesnt stop me from trying. The reward of seeing a redbud tree that had previously been obscured or an orchid peeking up through the leaf litter is all the reward I need. Every little but counts.
Great overview. Recently I’ve come across some writing (I don’t recall where) claiming that some invasive species can have beneficial effects, such as when they fill a niche left vacant by an extinct species. My own (common?) sense is that these examples might exist but are probably few and far between.
I’m wondering whether you might agree with that (the negative impacts far outweigh the positives for invasives in general, but maybe not necessarily on an individual species basis), or if we should be skeptical of species-specific examples of positive impacts too?
Thanks. Good thoughts, Darren. You've hit the nail on the head. Really depends on whether it's 'invasive' vs. just non-native. Invasive, by definition (depending on the definition), cause harm of some sort. Yes, there'll be some positive impacts, but for invasive, the costs always outweigh the benefits. For non-invasive non-natives it's a different story -- think of the veggies in your garden -- they're most likely non-native but highly beneficial and not problematic.
I’m pretty sure it did use the term invasives actually - I might be misremembering but I think one example was exotic algae in the Mediterranean that had some significant beneficial effect. Maybe a slightly different definition of invasive? Like, “taking over” but not in a destructive way?
Yeah perhaps. But this is the problem often -- that people misuse the term. There are benefits to every invasive species if you look carefully, but they pale in comparison to the costs.
Thanks. Haven't read it yet, but I already don't like the title because it's overly provocative (which is not what we need) and he's confusing terminology non-native vs. invasive non-native. There's a difference and it matters a lot as I point out. To say ecology has got it wrong is a little over the top. But I should read it before I pass judgement.
I understand your initial reaction but he goes into huance in the book. Doesn’t dismiss that many of these species can cause major harm but that these species are often scapegoats for previous destruction of the environment and that native is a shortsighted word as ecosystems are endlessly changing (change is cosmic). I am especially interested in the history of invasion biology and the conjunction with fascism and othering in relation to human-human relations ships and human-nature relationships (invasive/ native/ alien) which is especially relevant in current political climates :))) let me know what you think and any of your book recs :) 🌷
Thanks Emma -- I should give it a read -- the to-read pile is a bit overflowing though! Re: book recommendations, I don't have any that spring to mind for biological invasions. I've only read papers.
Thank you for the link! :) I would then specify the chapter ‘Nativism in the Garden of Eden’ which is roughly 20 pages. I think it’s important when publishing about a topic to understand where the topic comes from and the oppositions to it (pls look into the foundation of invasion biology). I can’t possibly express the nuance of the book in this reply but it defo gave me hope in the mounting challenges we all face in our changing landscapes :) sorry for my insistence and keep slaying your Substack !!
Yes, I’ve seen the articles on Substack arguing that invasive species shouldn’t be a big concern. As someone who also lives in an area heavily impacted by this issue, they disturbed me. Thanks for setting the record straight
My pleasure! I'll never get my head around that perspective. To be honest, my take is that it's dangerous to spread such messages when you have a relatively large audience.
I confess I’m shocked anyone could think invasive species are beneficial bc… “invasive”. It’s amazing how one can choose words so carefully and yet…
Anyway, love the expansion on impacts—I’m sure this work will help broaden and deepen the understanding of invasive species, and help keep the narrative more accurate.
Feral cat feeders are the worst. Hawaii is my childhood home and they are experiencing many of the same things as New Zealand. I was shocked on a recent visit to see a woman pull up with cartloads of food to feed the feral cats at the bottom of a beautiful canyon. The justification is that feeding them prevents them from hunting local wildlife, but any cat I've known eats their food and kills birds and rodents out of instinct. Meanwhile, at the local bird sanctuary, a volunteer was very forthright: "We kill the cats." Kudos!
I was also surprised to find the invasive species defenders here on Substack. What a strange lot! You throw them a bone by saying, "Don't demonize" species. But hey, some really need to be demonized!
There are some great channels on YouTube showing people hunting lion fish by the hundreds in the Caribbean. They are sold to local restaurants for fish tacos. Win win!
Feeding those cats is about as silly as it gets. All it’s doing is growing the population and causing spillover effects on the natives.
Yes, I don’t understand why folks would try to say we should shift our default mindset to thinking of them as having positive impacts. This includes environmental writers with more than 10k readers. The posts I’ve seen focus on a few cherry picked examples and build a case using them for all invasives being harmless. 🤷♂️
Then dingo was introduced into Australia 4000y ago and man arrived with fire 65000 years ago both have had a tremendous impact but both are seen now as indigenous. Where is the line drawn? in time or in impact?
I do believe we now have the technology to genetically sterilize the invasive species through hereditary genetic modification but if this then returns to the country of origin one assumes we could reverse it?
Once you start meddling in such ways, things can get very complicated. Hard to reverse such things. In NZ, we brought in predators to control invasive herbivores, which went onto decimate birds.
Re: where the line is drawn -- that's a very tricky one. There's no right answer here. But obviously the focus should be on the ones with the clearest impacts.
For the general public they may not see the ramifications of invasive species. For example, I work in the middle of a wildlife refuge. Folks come there and see the osprey, pelicans, seagulls, and an abundance of flowers. The impression they may get is that all is fine in this corner of Southern California.
Yet the island is completely overrun by invasive ants from Argentina. In the ten years that I've been there, I've never seen a native ant. Recent science confirms that the Argentine ants push out the native ants. When I go to the mountains, the landscape can be abuzz with native carpenter, sweat, and mason bees, bumblebees too! Although I see these creatures from time to time at my worksite, it's mostly populated by European honeybees.
About half of the flowers folks see at the refuge are invasive iceplant from South Africa and daisies from Europe. If we didn't push them back, they would take over the island.
In the meantime, native plants and animals are evolving to adapt to the presence of the invasives. The Argentine ants spread parasites and disease for almost all the native plants, placing evolutionary pressure on them.
And people just get used to invasive species and think of them as natural. The vistas of California, with the tan hillsides is said to be iconic, views seen in thousands of Hollywood movies. Those tan hillsides are covered with invasive European grasses.
A great example of shifting baselines syndrome, Paul. Thanks for your thoughts.
I will never get all the Japanese honeysuckle and Russian privet removed from our woods but that doesnt stop me from trying. The reward of seeing a redbud tree that had previously been obscured or an orchid peeking up through the leaf litter is all the reward I need. Every little but counts.
Absolutely, Lynn! Keep fighting the good fight.
We have a HUGE problem with all kinds of invasive species in Australia. Foxes, cane toads, feral cats are the big ones.
Starlings form beautiful, mesmerising murmurations made up of millions of birds, but they wreak havoc on Australian landscapes and agriculture.
What if you could use advanced genomics to prevent outbreaks?
You can!
https://unswscience.substack.com/p/meet-the-genetic-detective-tracking
Nice! Thanks for sharing.
Great overview. Recently I’ve come across some writing (I don’t recall where) claiming that some invasive species can have beneficial effects, such as when they fill a niche left vacant by an extinct species. My own (common?) sense is that these examples might exist but are probably few and far between.
I’m wondering whether you might agree with that (the negative impacts far outweigh the positives for invasives in general, but maybe not necessarily on an individual species basis), or if we should be skeptical of species-specific examples of positive impacts too?
Thanks. Good thoughts, Darren. You've hit the nail on the head. Really depends on whether it's 'invasive' vs. just non-native. Invasive, by definition (depending on the definition), cause harm of some sort. Yes, there'll be some positive impacts, but for invasive, the costs always outweigh the benefits. For non-invasive non-natives it's a different story -- think of the veggies in your garden -- they're most likely non-native but highly beneficial and not problematic.
I’m pretty sure it did use the term invasives actually - I might be misremembering but I think one example was exotic algae in the Mediterranean that had some significant beneficial effect. Maybe a slightly different definition of invasive? Like, “taking over” but not in a destructive way?
Yeah perhaps. But this is the problem often -- that people misuse the term. There are benefits to every invasive species if you look carefully, but they pale in comparison to the costs.
HIGHLY recommend reading The New Wild: Why Invasive Species will be our Salvation by Fred Pearce! For an alternative (less scary) perspective :)
Thanks. Haven't read it yet, but I already don't like the title because it's overly provocative (which is not what we need) and he's confusing terminology non-native vs. invasive non-native. There's a difference and it matters a lot as I point out. To say ecology has got it wrong is a little over the top. But I should read it before I pass judgement.
I understand your initial reaction but he goes into huance in the book. Doesn’t dismiss that many of these species can cause major harm but that these species are often scapegoats for previous destruction of the environment and that native is a shortsighted word as ecosystems are endlessly changing (change is cosmic). I am especially interested in the history of invasion biology and the conjunction with fascism and othering in relation to human-human relations ships and human-nature relationships (invasive/ native/ alien) which is especially relevant in current political climates :))) let me know what you think and any of your book recs :) 🌷
Thanks Emma -- I should give it a read -- the to-read pile is a bit overflowing though! Re: book recommendations, I don't have any that spring to mind for biological invasions. I've only read papers.
Well, if you're interested in those things, you might find this back and forth interesting between a bunch of prominent folks in invasion biology. Original paper: https://onlinelibrary.wiley.com/doi/full/10.1111/brv.70004. Response: https://academic.oup.com/bioscience/advance-article-abstract/doi/10.1093/biosci/biaf073/8158522?redirectedFrom=fulltext
Thank you for the link! :) I would then specify the chapter ‘Nativism in the Garden of Eden’ which is roughly 20 pages. I think it’s important when publishing about a topic to understand where the topic comes from and the oppositions to it (pls look into the foundation of invasion biology). I can’t possibly express the nuance of the book in this reply but it defo gave me hope in the mounting challenges we all face in our changing landscapes :) sorry for my insistence and keep slaying your Substack !!
😊 -- Thanks Emma. I'll try to get hold of the book. Cheers!
Yes, I’ve seen the articles on Substack arguing that invasive species shouldn’t be a big concern. As someone who also lives in an area heavily impacted by this issue, they disturbed me. Thanks for setting the record straight
My pleasure! I'll never get my head around that perspective. To be honest, my take is that it's dangerous to spread such messages when you have a relatively large audience.
Totally agreed
I confess I’m shocked anyone could think invasive species are beneficial bc… “invasive”. It’s amazing how one can choose words so carefully and yet…
Anyway, love the expansion on impacts—I’m sure this work will help broaden and deepen the understanding of invasive species, and help keep the narrative more accurate.
Thanks Tara! Yes, it makes no sense to me either.
Feral cat feeders are the worst. Hawaii is my childhood home and they are experiencing many of the same things as New Zealand. I was shocked on a recent visit to see a woman pull up with cartloads of food to feed the feral cats at the bottom of a beautiful canyon. The justification is that feeding them prevents them from hunting local wildlife, but any cat I've known eats their food and kills birds and rodents out of instinct. Meanwhile, at the local bird sanctuary, a volunteer was very forthright: "We kill the cats." Kudos!
There's also a feral cat feeding society of Google employees that have helped decimate burrowing owl populations in the Bay Area. It's astounding. https://www.nytimes.com/2018/05/26/technology/google-cats-owls.html
I was also surprised to find the invasive species defenders here on Substack. What a strange lot! You throw them a bone by saying, "Don't demonize" species. But hey, some really need to be demonized!
There are some great channels on YouTube showing people hunting lion fish by the hundreds in the Caribbean. They are sold to local restaurants for fish tacos. Win win!
Feeding those cats is about as silly as it gets. All it’s doing is growing the population and causing spillover effects on the natives.
Yes, I don’t understand why folks would try to say we should shift our default mindset to thinking of them as having positive impacts. This includes environmental writers with more than 10k readers. The posts I’ve seen focus on a few cherry picked examples and build a case using them for all invasives being harmless. 🤷♂️
Then dingo was introduced into Australia 4000y ago and man arrived with fire 65000 years ago both have had a tremendous impact but both are seen now as indigenous. Where is the line drawn? in time or in impact?
I do believe we now have the technology to genetically sterilize the invasive species through hereditary genetic modification but if this then returns to the country of origin one assumes we could reverse it?
Once you start meddling in such ways, things can get very complicated. Hard to reverse such things. In NZ, we brought in predators to control invasive herbivores, which went onto decimate birds.
Re: where the line is drawn -- that's a very tricky one. There's no right answer here. But obviously the focus should be on the ones with the clearest impacts.
Brilliant paper, brilliantly explained 🙏
Thanks so much, Kate! :)
really interesting and important work! Thanks for sharing this.
Thanks Emily!