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Anthony Ricciardi

@ecoinvasions.bsky.social

4K followers 980 following 860 posts

Ecologist (invasive species, freshwater biodiversity, bioinvasions, aquatic ecosystems) | Professor of Biology, McGill University | Director of the Bieler School of Environment | My lab account: @ricciardilab.bsky.social

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Environmental science 69%

Geography 17%

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Anthony Ricciardi @ecoinvasions.bsky.social · 17h

www.earth.com/news/seeds-o...

Seeds of change: How invasive animals are replanting islands

When native island animals vanish, plants lose their seed carriers. This shift weakens forests, water systems, and local cultures.

www.earth.com

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Anthony Ricciardi @ecoinvasions.bsky.social · 17h

A question is raised in this thread about how long after its human introduction should a species be considered native. It's not a question of 'citizenship' but rather evolutionary relationships -which change over time. Carthey & Banks propose a thoughtful criterion:
journals.plos.org/plosone/arti...

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Anthony Ricciardi @ecoinvasions.bsky.social · 1d

10/ Finally, the 2023 IPBES report is the most comprehensive global assessment of non-native species ever conducted. It gives unequivocal evidence that invasions threaten biodiversity & ecosystems - thus contradicting claims that concern over invasions is unwarranted.
www.nature.com/articles/s41...

Curbing the major and growing threats from invasive alien species is urgent and achievable - Nature Ecology & Evolution

This Perspective highlights the global consensus on the urgency and growing threat of invasive alien species, and management needs, as found by the 2023 report on invasive alien species conducted by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).

www.nature.com

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Anthony Ricciardi @ecoinvasions.bsky.social · 1d

9/ The global rate of species introductions has shown no sign of saturation. Under human influence, species are moving exponentially faster, farther, & in greater numbers than at any other time in Earth's history, creating novel evolutionary pressures on naive biotas. www.nature.com/articles/nco...

No saturation in the accumulation of alien species worldwide - Nature Communications

Alien species of animals and plants can invade new regions of the earth. This study performs a global analysis of temporal dynamics and spatial patterns of alien species introductions over the past 200 years, and reports no saturation in the rate at which these invasion are increasing.

www.nature.com

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Anthony Ricciardi @ecoinvasions.bsky.social · 1d

8/ Invasions interact with other global stressors (climate change, organic pollution, land use) in unpredictable, synergistic ways. Stressors may trigger even benign nonnative spp to become disruptive. Such interactions pose major challenges for ecosystem management.
academic.oup.com/bioscience/a...

The Invasion Ecology of Sleeper Populations: Prevalence, Persistence, and Abrupt Shifts

ABSTRACT. It is well established that nonnative species are a key driver of global environmental change, but much less is known about the underlying driver

academic.oup.com

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Anthony Ricciardi @ecoinvasions.bsky.social · 1d

7/ Due to proliferating human vectors, increasing numbers of novel predators, pathogens & ecosystem engineers are being introduced to insular systems (lakes, islands) and to regions whose communities have no evolutionary experience with such species and are therefore vulnerable to disruption.

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Anthony Ricciardi @ecoinvasions.bsky.social · 1d

6/ Although some native species can also become superabundant & damaging (but only when triggered by disturbance), non-native species are far more likely to be implicated as a cause of global extinction:
t.co/9NUoV81a54

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Anthony Ricciardi @ecoinvasions.bsky.social · 1d

5/ Paleontological evidence also links invasions to mass extinction - and suggests that modern human-assisted invasions may similarly result in the “extinction of geographically restricted ecological specialists and suppression of vicariant speciation of new species".
www.cbc.ca/news/science...

Invasive species play role in mass extinctions | CBC News

The arrival of invasive species can prevent the formation of new species and help to trigger mass extinctions, according to a study published Thursday.

www.cbc.ca

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Anthony Ricciardi @ecoinvasions.bsky.social · 1d

4/ An analysis of the IUCN Red List (described as "the world's most comprehensive inventory of the global conservation status of biological species") implicates invasions as a major cause of extinction over the past 500 years.

royalsocietypublishing.org/doi/10.1098/...

Alien species as a driver of recent extinctions | Biology Letters

We assessed the prevalence of alien species as a driver of recent extinctions in five major taxa (plants, amphibians, reptiles, birds and mammals), using data from the IUCN Red List. Our results show ...

royalsocietypublishing.org

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Anthony Ricciardi @ecoinvasions.bsky.social · 1d

3/ Evidence from various studies (some shown below) & taxonomic groups have implicated invasions as the sole or contributing cause of a large proportion of global animal extinctions.

An additional line of evidence comes from recoveries of native species following invasive species eradications.

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Anthony Ricciardi @ecoinvasions.bsky.social · 1d

2/ The impacts of the vast majority of #bioinvasions have not been studied.

Most non-native species are assumed to be benign. A small fraction (but an increasing total number) of invaders are shown to have substantially altered ecosystems and caused local, regional, and global extinctions.

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Reposted by Ingolf Kühn, Graeme S. Cumming, Julie L. Lockwood

Anthony Ricciardi @ecoinvasions.bsky.social · 1d

1/🧵 Over the past decade, misinformation in the popular media & the opinion pages of some journals has promoted the claim that concern over species invasions is overblown, because "most invasions do not cause extinctions".

Here is a brief reminder of what scientific evidence shows...
#bioinvasions

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Anthony Ricciardi @ecoinvasions.bsky.social · 1d

Quote: "Introductions of plants and animals have subverted island ecosystems and, as a consequence, endemic island species represent a disproportionately high number of the world’s extinctions."
theconversation.com/and-then-the...

And then there were none: Australia’s only shrew declared extinct

Australia’s only known shrew has been declared extinct. Its loss emphasises the need for national protection of Australia’s rare and unique wildlife.

theconversation.com

Anthony Ricciardi @ecoinvasions.bsky.social · 2d

In the Acknowledgements, the authors thanked "the three thoughtful reviewers that provided comments".

I wonder how many invited reviewers declined?

Anthony Ricciardi @ecoinvasions.bsky.social · 2d

The reviewer crisis: data from the journal Biological Invasions:

"Reviewer acceptance rates dropped steadily over the past two decades. Early-career researchers had the highest acceptance rates, while senior scholars were least likely to accept review invitations."
link.springer.com/article/10.1...

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Anthony Ricciardi @ecoinvasions.bsky.social · 3d

So do I.

Astrobiology @astrobiology.bsky.social · 3d

Reposted by Julie L. Lockwood

Anthony Ricciardi @ecoinvasions.bsky.social · 3d

Beautiful.

William (Bill) Sutherland @billsutherland.bsky.social · 3d

At end of excellent CCI meeting about future plans we remembered Jane Goodall (who did her PhD in Zoology). Instead of a minute silence we opted for a minute noise - full of clapping and hooting. Much more suitable!

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Anthony Ricciardi @ecoinvasions.bsky.social · 3d

This recent study is important enough to post again.

Quote: "We advise caution regarding the intentional introduction of large mammalian herbivores for conservation purposes (rewilding, assisted colonization) without rigorous assessment of their impacts on native communities."

Anthony Ricciardi @ecoinvasions.bsky.social · 25d

New study comparing positive & negative impacts of nonnative large herbivores on native species. #bioinvasions

"Negative impacts are more common, and of higher magnitude than positive impacts. Reported impact magnitudes decline over time only for positive impacts."
www.nature.com/articles/s41...

Harms of introduced large herbivores outweigh benefits to native biodiversity - Nature Communications

Using impact assessment frameworks, this study shows that the introduction of large mammalian herbivores outside their native range has predominantly caused negative impacts on native biodiversity glo...

www.nature.com

Anthony Ricciardi @ecoinvasions.bsky.social · 3d

Non-native omnivorous mammals (pigs & rats) have often replaced native frugivorous birds, bats & tortoises. These replacements have different physical traits that affect the size of seeds they can carry. Consequently, the long-term survival of native plants is threatened.
phys.org/news/2025-10...

Introduced animals change how island plants spread, global study finds

On islands, many plants rely on animals such as birds, bats and reptiles to disperse their seeds and help them grow in new places. When native animals go extinct, this naturally reduces seed dispersal...

phys.org

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