Yellow crazy ants (Anoplolepis gracilipes)
Image Credit: luooyuoo at iNaturalist
(CC BY-NC 4.0)
Scientific Frontline: Extended "At a Glance" Summary: Animal Welfare Impacts of Biological Invasions
The Core Concept: Biological invasions inflict significant, measurable suffering—including injury, stress, and behavioral disruption—on individual native and introduced animals globally.
Key Distinction/Mechanism: Unlike traditional invasion science, which focuses primarily on ecological biodiversity loss and economic damage, this methodology uses a structured assessment to specifically quantify the individual suffering and physical toll caused by invasive species.
Major Frameworks/Components:
- Animal Welfare Impact Classification for Invasion Science (AWICIS): A standardized, publicly available tool developed to categorize and compare the severity of animal welfare impacts.
- Behavioral and Physical Markers: The use of specific biological indicators, such as stereotypic self-damaging preening and injurious aggression, to infer poor welfare in the wild.
- Integration of Existing Data: Repurposing current biodiversity and ecological studies to extract physiological data, stress markers, and immune responses for wild animal populations.
Branch of Science: Invasion Biology, Animal Welfare Science, Conservation Biology, Zoology, and Veterinary Science.
Future Application: Guiding environmental policymakers to integrate welfare assessments into global biosecurity measures, and identifying vulnerable wild animal populations that require targeted, immediate protection from invasive species.
Why It Matters: The findings expose a largely hidden global crisis, demonstrating that invasive species (such as highly disruptive invasive ants) cause severe suffering wherever they are introduced. This reframes biological invasions as an urgent ethical priority, rather than strictly an ecological one.
It is well known that biological invasions can be severely harmful to native biodiversity—preventing the damage they cause is a global conservation priority. A new study by the University of Bristol has highlighted a different type of impact that they cause—the often-overlooked animal welfare consequences of biological invasions. The research, published in Nature Communications on May 5, reveals that invasive species can cause significant suffering to both native and introduced animals worldwide.
Biological invasions occur when organisms, such as animals and plants, are introduced to regions of the world where they do not naturally occur. It is already known that they can be severely harmful to biodiversity, for example, by causing the extinction of native species, and they can also affect human health and well-being by spreading diseases to people or by hindering agricultural activities. In fact, the impacts of biological invasions on biodiversity and people have been studied for many years.
In this study, the researchers have developed a new framework to assess how biological invasions affect the welfare of individual animals, providing a structured way to identify and compare impacts such as injury, stress, and behavioral disruption.
The framework, called the Animal Welfare Impact Classification for Invasion Science (AWICIS), was applied to existing studies of invasions involving birds and ants, two globally widespread groups with very different types of impacts.
The study found that invasive ant species frequently cause severe welfare impacts wherever they establish, while introduced bird species have less severe effects. However, the researchers caution that many impacts are underreported, particularly those affecting introduced animals themselves.
Tom Evans, a research fellow in biodiversity and animal welfare at the Bristol Veterinary School and a coauthor of the study, said: “Using AWICIS, we show that the animal welfare impacts of biological invasions are a global phenomenon—they can cause the widespread suffering of animals, and in some cases, this suffering is severe. Indeed, some ant species tend to cause severe welfare impacts on animals wherever they are introduced.”
Mike Mendl, a professor of animal behavior and welfare at the Bristol Veterinary School and a coauthor, added: “Poor welfare and suffering, including in wild animals, can be inferred from changes in certain physical and behavioral signs. Examples include injuries, stereotypic self-damaging preening behavior, and injurious aggressive behavior.
“While physiological data, such as immune markers and stress hormone levels, are less commonly collected in studies of wild animals, they could provide valuable additional insight into the severity of welfare impacts.”
The researchers suggest that existing studies on biodiversity impacts represent an untapped resource for understanding animal welfare consequences. By integrating welfare assessments into invasion biology, the framework could help conservationists, policymakers, and animal welfare scientists better evaluate the full costs of invasive species.
The findings could be used to identify vulnerable animals that require protection from the welfare impacts caused by biological invasions. The research suggests that improving global biosecurity is crucial to prevent biological invasions and the animal suffering they cause.
The researchers hope the study will encourage greater consideration of animal welfare in environmental management decisions and encourage further research into the hidden suffering caused by biological invasions. AWICIS is a publicly available tool that can be used by research scientists who wish to assess the animal welfare impacts of biological invasions.
Reference material: What Is: Invasive Species
Published in journal: Nature Communications
Title: Quantifying and categorising the animal welfare impacts caused by biological invasions
Authors: Thomas Evans, and Michael Mendl
Source/Credit: University of Bristol
Reference Number: bio050526_01
.png)
.jpg)