Search is on for 3 escaped monkeys after truck overturns on Mississippi highway

People wearing protective clothing search along a highway in Heidelberg, Miss., on Wednesday, Oct. 29, 2025, near the site of an overturned truck that was carrying research monkeys. (AP Photo/Sophie Bates)

HEIDELBERG, Miss. — Three monkeys remained on the loose Wednesday as searchers in masks, face shields and other protective gear scoured fields along a rural Mississippi highway where a truck carrying the primates overturned a day earlier.

It remained unclear who owns the monkeys, who was transporting them and where they were being taken when the truck crashed on Interstate 59 north of Heidelberg. Authorities have said most of the 21 monkeys were killed but haven’t elaborated on just what occurred.

The Jasper County Sheriff’s Department has said animal experts from Tulane University examined the trailer Tuesday evening and determined three monkeys had escaped.

The truck was carrying Rhesus monkeys, which typically weigh about 16 pounds (8 kilograms) and are among the most medically studied animals on the planet. Video recorded after the crash showed monkeys crawling through tall grass beside the interstate, where wooden crates labeled “live animals” were crumpled and strewn about.

The truck was no longer at the scene Wednesday, but the searchers in gear including white coats, gloves and hair nets were checking fields, aided by law enforcement officers.

Jasper County Sheriff Randy Johnson said Tulane officials reported the monkeys were not infectious, despite initial reports by the truck’s occupants warning that the monkeys were dangerous and harboring various diseases. Nonetheless, Johnson said the monkeys still needed to be “neutralized” because of their aggressive nature.

The monkeys were being housed at the Tulane University National Biomedical Research Center, which routinely provides primates to scientific research organizations, according to the New Orleans school. The research center is located in Covington, Louisiana, about 40 miles (65 kilometres) north of New Orleans.

The 21 monkeys had recently received checkups confirming they were pathogen-free, Tulane said in a statement Wednesday. The university said it wasn’t transporting the monkeys and didn’t own them, but sent a team of animal experts to help with their care.

All other monkeys were being transported back to Louisiana.

About 10 years ago, three macaques in the breeding colony of the Tulane National Primate Research Center were euthanized after a “biosecurity breach,” federal inspectors wrote in a 2015 report. The breach involved at least one staff member failing to adhere to biosafety and infection control procedures, it said. The facility made changes in its procedures and retrained staff after that happened, according to the report from the U.S. Animal and Plant Health Inspection Service.

The Mississippi Highway Patrol said Wednesday that it was investigating the cause of the crash, which occurred about 100 miles (160 kilometres) from the state capital, Jackson.

Dr. James Watson, Mississippi’s state veterinarian, verified that the animals had the proper documents and “certificate of veterinary inspection” for legal transport across state lines, he said in an email to The Associated Press. The state’s Board of Animal Health wasn’t involved in the response to the crash, and additional information would need to come from Tulane, he said.

If anyone sees monkeys, they should call the authorities and shouldn’t approach the animals, the sheriff’s office has warned.

Rhesus macaques “are known to be aggressive,” according to the Mississippi Department of Wildlife, Fisheries and Parks. It said the agency’s conservation workers were working with sheriff’s officials in the search for the animals.

The search comes about one year after 43 Rhesus macaques escaped from a South Carolina compound that breeds them for medical research because an employee didn’t fully lock an enclosure. Employees from the Alpha Genesis facility in Yemassee, South Carolina, had set up traps to capture them.

Sophie Bates, The Associated Press