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A recent review of over 312 studies has identified dozens of unique uses of roadkill in scientific research. The review, published in Biology Letters, discusses the advantages of using roadkill instead of live wildlife and encourages researchers to consider this option more frequently.

Refinement, replacement, reduction

There are many reasons for using animals in research. In many cases, this involves studying the species itself, or effects from its environment. Other research may involve disease surveillance, diet analysis, genetic studies, or obtaining specimens for use in training veterinarians. Still, there are rules and regulations surrounding the use of wildlife in research.

One set of ethical standards was put in place by The Organization for Economic Co-operation and Development and World Health Organization, along with several countries. This framework is referred to as the "3Rs" (refinement, replacement, reduction) and aims to promote more humane science by replacing animals with non-animal alternatives when possible, reducing the number of animals used to the minimum needed, and refining procedures to minimize pain, suffering and distress for animals that are used.

Using roadkill, when possible, is an ethical alternative to live animals in research. It is easily obtained in many regions of the world and, the study authors argue it has other benefits as well.

"Furthermore, the use of roadkill represents a potential time savings, as it does not require researchers and committees to spend limited time on ethics applications. Thus, any study that requires a sample from the body of the animal for further analysis could be partially or completely achieved using roadkill samples, assuming they are in sufficient numbers (or supplement sampling if not)," the researchers write.

The many scientific applications of roadkill

To gather a list of potential uses for roadkill in research, the team conducted a systematic literature review in the Web of Science and Scopus for studies conducted between 1900 and 2025. Out of the 312 studies that fit their criteria of uses of roadkill for purposes beyond roadkill mitigation, at least 650 species were studied, with mammals most represented, followed by reptiles, birds, amphibians and invertebrates.

After sorting and categorizing the papers by the way they used roadkill in their study, the researchers separated uses into two main categories: broad-use and specific-use. Of all the studies, 26 broad-use and 91 specific-use categories were found. Broad use categories included uses like anatomy, microbiome, species ecology, parasites and teaching.

Many of the specific uses surprised even the study team. These included things like demonstrating aspects of fossilization—a process similar to the way roadkill gets flattened over time, use as a food source for captive animals in reintroduction programs and identifying high-priority areas for conservation.

"In addition to alternate uses of roadkill that might seem intuitive, as touched on above, we found several examples that seemed particularly novel. Two studies used roadkilled white-tailed deer (Odocoileus virginianus) as bait to attract the actual study species (golden eagle, Aquila chrysaetos).

"In another study, roadkilled snakes (Iberian adder, Vipera seoanei) have been used to investigate evolution in this species; samples were used for molecular analysis. In the context of veterinary science, an examination of the location and frequency of bone fractures in roadkilled mammals (northern tamandua, Tamandua mexicana) has been used to aid decisions for veterinary treatment of such animals that survive being hit by vehicles," the study authors write.

Caveats and considerations

While roadkill presents an opportunity in many areas of science, it does have its limitations. Obviously, decomposition and scavenging can limit sample quality and availability in many cases. Studies that require newer specimens may have to find ways of detecting them before too much damage occurs. As most regions require a permit for taking away either living or deceased wildlife, this will need to be taken into account, along with many safety precautions.

The team also notes the potential for sampling bias when using roadkill. They write, "True random sampling is not possible when using roadkill as a source of samples, for at least two reasons: roads are built in specific areas according to human needs rather than with wildlife sampling in mind, and species will differ in vulnerability, and even individuals within species, due to driver behavior and animal behavior."

To help limit this bias, the team suggests researchers make efforts to sample from a range of road types and speed limits, which might affect the species composition or behavioral and life history type composition of the animals. They also note that other researchers should consider returning unused portions of roadkill farther away from the roadside to maintain a food source for scavengers, while reducing their risk of being hit.

Written for you by our author Krystal Kasal, edited by Gaby Clark, and fact-checked and reviewed by Robert Egan—this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive. If this reporting matters to you, please consider a donation (especially monthly). You’ll get an ad-free account as a thank-you.

Publication details

Christa Beckmann et al, Roadkill reimagined: a review of innovative scientific use and value of animals killed by vehicular traffic, Biology Letters (2026). DOI: 10.1098/rsbl.2025.0471

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Citation: Roadkill offers an ethical alternative to live wildlife in scientific research (2026, January 28) retrieved 28 January 2026 from https://phys.org/news/2026-01-roadkill-ethical-alternative-wildlife-scientific.html

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