How non-native species are saving themselves from extinction

Next time you spot a Norway rat scurrying around in Central Europe, remember, it’s not technically a local. Non-native species, often introduced by humans, are causing a significant decline in indigenous species, globally.

They have been implicated in a colossal 60 percent of worldwide species extinctions in recent years. A new study shows that some non-native species are now endangered in their homeland, and would benefit from conservation measures to protect them.

Effect of globalization on species distribution

This intriguing find comes from a collaboration of biologists from the University of Vienna and La Sapienza University in Rome.

The study, published in the journal Conservation Letters, examines the paradoxical conservation predicaments posed by non-native species.

Our increasingly interconnected world has caused many animal and plant species to migrate to new areas. These invasive species can endanger local species by introducing competition or new diseases. Interestingly, though, some of these invasive species are facing extinction in their native homes.

This presents a compelling paradox, and prompts questions about whether we should protect or control non-native populations of endangered species.

Extent of the paradox

The recent study explores how widespread this conservation paradox is among non-native mammal species. Worldwide, humans have introduced 230 mammal species to new regions.

“We were very surprised by this high number, as we assumed that invasive species are also common in their area of origin,” noted study lead author Lisa Tedeschi from La Sapienza University and the University of Vienna.

Unexpected saviors: Foreign territories

The study details interesting instances where invasive species have flourished outside their native lands.

For example, the crested macaque and wild rabbit both face severe declines in their original habitats whereas, in new territories, their numbers have remained stable or even increased. This finding implies that invasive populations could potentially rescue these endangered species from extinction in their homelands.

Role of globalization in nature conservation

The study raises valid questions about the current methods for assessing global extinction risks. Often, non-native populations are not considered in these assessments.

However, the researchers argue that including these populations could improve the threat assessment for some species.

Franz Essl, a biodiversity researcher from the University of Vienna, states that this could decrease the global extinction risk for 22 percent of the analyzed species.

Protection efforts for non-native species

While recognizing the value of non-native populations in species conservation, the study also warns of potential downsides. Diverting attention towards such populations could reduce protection efforts for native ranges which may be more threatened.

Plus, these species could negatively impact the local flora and fauna of their new range. Franz Essl concludes that the future may see more species threatened in their native ranges but thriving in new areas.

Thus, the tricky task of striking a balance between the benefits and risks of non-native populations needs to be addressed.

Non-native species are not always invasive

Non-native species are not always considered invasive. In some cases, they integrate into ecosystems without causing significant harm.

For example, certain plants and animals introduced centuries ago have become naturalized, contributing to biodiversity and even serving as critical resources for local wildlife. The distinction between invasive and non-invasive alien species is vital for targeted conservation efforts.

Additionally, non-native species are often unintentionally introduced through human activities such as trade, tourism, and transportation.

For instance, the zebra mussel, native to Eastern Europe, spread across North America by hitching rides on ships. Once such species are established, controlling them can be costly and challenging, often requiring coordinated international efforts.

Different types of non-native species

While many discussions focus on mammals, non-native species include a wide range of organisms such as birds, insects, and plants.

Non-native plants like kudzu in the United States can outcompete native flora, while insect species, such as the emerald ash borer, have devastated tree populations in North America. These examples highlight the need for comprehensive management strategies across multiple species and ecosystems.

Climate change further complicates the issue, as shifting temperatures and habitats can make regions more hospitable to different types of non-native species.

This can exacerbate their spread, introducing new risks to ecosystems that are already under stress. Understanding the interplay between climate change and non-native species is critical for future conservation policies.

The study is published in the journal Conservation Letters.

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