Nissan’s new car alarm is silent to humans but scary to rabbits. It could save their lives

Every year, American cars hit a staggering 1 million large animals like deer and elk. In California—a roadkill hot spot—vehicle collisions with animals cost more than $200 million every year.

To address the problem, experts have long advocated for wildlife crossings that either span over high-speed freeways or burrow under them to help animals cross over safely. (The world’s largest wildlife crossing is set to open in 2026 in California, where it will help reconnect habitats bisected by the 10-lane 101 Freeway.) Other strategies involve reducing traffic or closing roads altogether at peak animal crossing times. Now, a new solution might be on the horizon, and it is mounted on the culprits themselves: cars.

December 2024 marked the beginning of an ambitious experiment on the Japanese island of Amami Oshima. The island is known for its beautiful beaches, its handwoven silk, and a particularly dark-furred species of rabbit known as the Amami rabbit. Since 2004, the Amami rabbit has been an endangered species because logging and urban development have reduced its forest habitat, but also because the animals are often hit and killed by cars. According to Japan’s Ministry of the Environment, incidents involving Amami rabbits have increased for seven consecutive years, culminating in 147 deaths in 2023 alone.

Three years ago, a team comprised of designers, government officials, researchers from three different universities in Japan, plus one automaker, set out to find a solution. The automaker? Nissan. The solution? A high-frequency alarm that is mounted at the front of the car to warn animals of its presence. The project, which was funded by Nissan, has been dubbed Animalert, and it is the brainchild of Tokyo-based ad agency studio TBWA\Hakuhodo.

An alert is born

The story began while TBWA\Hakuhodo was working on a marketing campaign to promote the sound that Nissan’s EV cars make to alert pedestrians. (Stripped of the loud engines that come with their fuel-powered counterparts, electric vehicles are twice as likely to hit pedestrians.) Back in 2010, Nissan was one of the first automakers to introduce this kind of alert, which is known as a Vehicle Sound for Pedestrians, or VSP. But as Shuichiro Tsuchiya, project lead at TBWA\Hakuhodo, notes, not many people know they exist (hence the marketing campaign).

The team was brainstorming ideas when the news came out that Amami rabbits were being killed by cars at unprecedented rates. Almost immediately, they thought: could the vehicle sound for pedestrians be adapted to warn not just humans but animals, too?

To find the answer, the team embarked on a journey that would end up taking more than three years. If the experiment proves successful—and enough automakers jump on the bandwagon—the technology could be expanded to work on other animals, and help reduce roadkill worldwide.

A double-whammy marketing campaign

According to Japanʼs Ministry of Land, Infrastructure, Transport and Tourism, more than 120,000 animals were killed on Japanese roads in 2022. The most commonly affected species were dogs and cats, closely followed by raccoon dogs, birds, and deer.

Rabbits, in particularly those who live on Amami Oshima, were not on the list. Nonetheless, they were the perfect species for a pilot. Deer and other animals are scattered all over Japan, which would have made testing a new alarm with them difficult. “We would need devices for hundreds of thousands of cars,” Tsuchiya told me. The team only had one car at their disposal: a Nissan Sakura.

Instead of launching a nationwide experiment, they narrowed down their focus on Amami Oshima, which covers about 275 square miles. The contained environment helped increase the team’s chances of encountering rabbits. And because—let’s not forget—the project still doubled as a marketing campaign, it helped them weave a compelling story. That of a conscientious automaker working to save rabbits lives.

Fine-tuning the sound

From the very beginning, TBWA\Hakuhodo partnered with the Ministry of Environment and the Amami City Government, which helped speed up government approvals. They also partnered with three universities, particularly Masachika Tsuji from Okayama University of Sciences, who has previously studied sound as an animal deterrent. (Most recently, his team helped install speakers at three major airports in Japan, where each speaker emits high-frequency waves designed to deter birds from flying near the runways.)

Together, the team worked to find the right range of high-frequency sounds. The exact frequency remains undisclosed, but the resulting sound is one that rabbits have never heard before because it doesn’t exist in the natural world. “It’s almost like they encounter a ghost,” Tsuchiya says.

The team performed two initial tests. First, they ran tests at Nissan’s R&D lab, to determine the most suitable position for the speaker that would emit the sound. Then, they traveled the island, where they placed a speaker in a field where rabbits are known to live to gauge their initial response.

The first experiment worked and the rabbits that were there left the field almost immediately. So, the team installed the speaker on the car, and took to the roads. Amami rabbits are nocturnal, so the team ran tests at night. So far, they have tested the speaker over the course of five nights, driving the car at 6 miles per hour between 10 p.m. and midnight. Each time they drove, they recorded the view in front of the car with a drive recorder, so they could analyze it later.

The ripple effect

So far, they have encountered about 100 rabbits. Tsuji, the professor, explains that the team also tested the sound on other animals including deer, wild boars, and birds. He says that the car-mounted alarm only lasts for a fleeting moment (as long as it takes for a car to pass by). That time is long enough to deter animals, but not long enough to harm them. And since sound gets absorbed by trees and grass, it only affects animals on or near the road.

So far, the results are promising, but more research is necessary before they can make concrete claims or publish a paper. The team is yet to identify the exact radius within which Animalert would be most effective. (In the artificial conditions of a lab, they say it can go as far as 160 to 200 feet.) Also, they are yet to test the technology while driving at the local speed limit, which is about three times the speed they used during testing.

For an animal alert like this to be effective, critical mass is key. Eventually, the team is hoping to develop various high-frequency sounds that can force other animals, like deer, to flee the road as a car approaches. These sounds could be switched on by the driver based on the animals that live in the area. Or more aspirationally, they could be automatically adjusted by the car’s GPS.

But for the technology to really make a dent and reduce roadkill worldwide, it would have to be implemented by as many automakers as possible. Like so many problems plaguing the world today, this is a problem that can only be addressed if competitors band together to solve the same goal.

Still, Animalert is a promising start to a solution that could easily ripple across the industry. It would save many lives—and many dollars, too.

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