It started with black bears.

It was 1999, and University of Minnesota researcher Paul Iaizzo connected with Tim Laske, now vice president of research in Medtronic's cardiac ablation products business.

The two started talking and realized that Medtronic monitoring devices could help Iaizzo's research that focuses on black bear behavior and health, especially during hibernation. Iaizzo, who runs the U's Visible Heart Laboratories, estimates that he has implanted 300 to 400 cardiac monitors into bears over the years.

Iaizzo wants to see if how bears hibernate can be applied to human medicine, for example in an intensive care unit.

"If you could hibernate a human like a bear does, it would be amazing," Iaizzo said.

Since then, wildlife conservationists from across the U.S. and the globe — from Norway to Greenland and Brazil to Kenya — have approached Medtronic to inquire about the Linq monitors.

Hundreds of animals now have implanted devices made by Medtronic, which has operational headquarters in Fridley. Nearly two dozen species — including gorillas, giraffes, moose, jaguars, orangutans and mule deer — are being monitored through the devices. Those include wolves and other animals at the Wildlife Science Center in Stacy, Minn.

A first-ever project with elephants in Thailand is slated to start this fall. A project involving wolverines will likely start in 2024.

"The project has evolved pretty significantly over time," said Laske, who leads the wildlife projects.

While many of the monitors are used for research purposes, the Great Ape Heart Project, based at the Detroit Zoo, is using them to track cardiac health. Heart disease is a major cause of mortality in great apes, especially as they live longer with better veterinary care, according to the project.

Medtronic has worked with the project since its inception in 2010. Six great apes at the Columbus (Ohio) Zoo and Aquarium — including bonobos for the first time — received Linq monitors in 2022.

The monitors can measure heart rate, body temperature and an animal's activity.

Male bonobos Jimmy, 42, and Maiko, 38; orangutans Dumplin, 48, and Sulango, 29; and silverback gorillas Mac, 38, and Ktembe, 25, received the monitors because they had the same type of health problems humans face, such as high blood pressure.

"It's remarkable how similar the hearts of these species are to those of human patients," said human cardiologist Dr. Ilana Kutinsky, who works with the Great Ape Heart Project, in a statement for the Columbus Zoo. "It means we can use similar treatments we apply to our human patients. Tracking the heart rhythms of these orangutans, bonobos and gorillas will provide the zoo's veterinarians critical information about how to best manage any cardiac issues that arise."

The devices track the apes' heart activity for signs of irregular heartbeats, called arrhythmias. Zoo caretakers regularly move the animals toward monitors that pick up and transmit data from the devices. The Great Ape Heart Project then monitors the data and alerts Columbus Zoo veterinarians to any abnormalities.

Dr. Priya Bapodra-Villaverde, senior veterinarian at the zoo and an adviser for the Association of Zoos and Aquariums' Bonobo Species Survival Plan, said using monitors will advance veterinary care for their species.

Now that the cardiac monitors are implanted, the animal care team will ensure that the six apes routinely move near a receiver that will upload the data via cellphone signals to the Great Ape Heart Project. Experts will monitor the information in real time and send a clinical alert to the Columbus Zoo team if they see anomalies. The zoo's veterinarians can then adjust medications or provide other treatment as needed.

Just as in humans, cardiac health problems often go undetected in earlier stages, said Marietta Danforth, the Great Ape Heart Project director.

The Linq is the size of several matchsticks, so it can be inserted with a scalpel instead of full surgery and requires only a few stitches afterward. A researcher with the Smithsonian's National Zoo & Conservation Biology Institute compares it to inserting a microchip in a dog or cat, although the monitors for the great apes are inserted when they are under anesthesia for exams.

The institute in 2017 started using the monitors to study endangered maned wolves, including a 2021 field study in Brazil. Maned wolves are sometimes called foxes on stilts but are neither wolves nor foxes but a unique species.

Found only in South American savannas, the animal is considered a keystone species because its habits — hunting small rodents, which keeps pest populations down, and eating native plants, which spreads seeds through its waste — are essential to the ecosystem.

But the animals are secretive in the wild, so it is hard to observe them and figure out what causes them stress, according to the institute's Rhythm of Life Project.

Researchers discovered surprising information through the monitors — for example, maned wolves' heart rates can be below 30 at rest but at 330 when most stressed. The project also studies mating patterns and how to foster more generations of the species, and how human interaction affects conservation.

As research papers are published on animals with heart monitors, Laske is fielding increasing numbers of inquiries about other potential projects. The demand is starting to outpace the supply of available monitors; Laske is selective about the project partners he chooses. He said that many of the projects are focused on conservation physiology.

Monitoring with the devices "gives you a much fuller picture of the reaction of an animal to its environment," said Laske.

Focused on research and education, the Wildlife Science Center in Stacy has about 90 wolves on its 210-acre grounds. Executive director Peggy Callahan said that 12 of its wolves currently have heart monitors.

Callahan said that the heart rate information can tell them how wolves are responding to their environment.

"We see wolves have a certain response to people. Sometimes it's aggressive, sometimes it's excitement, sometimes it's fear," said Callahan.

The goal is to understand their behavior so the animals can have the best life possible.

Wolves have varied reactions to visitors or to people cleaning their enclosures. Based on the heart rate data, Callahan said that they can, for example, make changes to cleaning schedules to help the wolves.

"We try to reduce that stress," she said "It kind of gives us an idea of how to make their lives better."

Four mountain lions and three black bears at the center also have cardiac monitors.

The wildlife work is not related to Medtronic's extensive portfolio of animal veterinary products, which include brain monitoring, pulse oximetry and surgical instruments.

It also is not a money-making venture for Medtronic. The company donates the heart monitors, typically devices that are beyond their shelf life and can no longer be used in humans.

The work is personally important to Laske, who originally aspired to be a wildlife biologist. He works with Iaizzo as an adjunct assistant professor at the University of Minnesota.

"For me it's essentially a second job. I'm incredibly passionate about the wildlife work," said Laske.

Iaizzo's team follows about 20 black bears tracked by the Minnesota Department of Natural Resources that have heart monitors.

"The bears have really been the foundation of the work," Laske said.