“Bobcats are disease defenders,” Zara McDonald, founder of the U.S.-based conservation nonprofit Felidae Conservation Fund, tells host Mike DiGirolamo on Mongabay’s weekly podcast Newscast in February.

Today, bobcats (Lynx rufus) are North America’s most common small wildcat. But this wasn’t always the case: At the start of the 20th century, the bobcat population was close to zero in North America, DiGirolamo says, but by 2011, there were around 3.5 million bobcats in the U.S. alone.

McDonald calls bobcats “silent public health guardians” that provide an “invaluable ecological service” as they regulate the population of rodents, raccoons and rabbits that are reservoirs for disease through parasites, bacteria or viruses. For example, she says, bobcats help curb Lyme disease by preying on white-footed mice (Peromyscus leucopus), which are considered the primary animal reservoir of the Borrelia burgdorferi bacteria that causes Lyme disease, transmitted through tick bites.

“By eating the rodents, they directly reduce the tick population,” McDonald says. “Bobcats are dead-end hosts, so they don’t serve as efficient hosts for certain pathogens.”

While the population of bobcats has grown in the U.S., McDonald says she would consider the population “healthy” but not really to have “rebounded tremendously.”

In the state of California, regulation prohibiting bobcat hunting has helped, but McDonald says she’s concerned about officials considering reinstating hunting in the state.

“There’s so many benefits that bobcats bring to an ecosystem that I think it’s important for people to … understand that,” McDonald says.

She explains that bobcats are “very benign mesocarnivores” that do not attack humans, especially since they are not comfortable around people, even in urban landscapes. “I think you do have this misinformation that circulates around any kind of predator and … bobcats get roped into that,” McDonald says.

At the same time, human expansion into territories that bobcats are present in has impacted the species’ health. While bobcats help curb diseases, they are also seeing an increased risk of diseases from domestic pets like cats.

“So, toxoplasmosis is one that we’re looking closely at,” McDonald says, referring to her organization Felidae Conservation Fund. “Toxoplasmosis is quite interesting and important because it raises dopamine levels and changes behavior of those infected. So, in the case of a bobcat or a mountain lion, it will make them take riskier behaviors. So that means more likely to potentially take a pet or get into trouble in human urban environments.”

The Felidae Conservation Fund has started a pilot study called the “Wild Cat Health Project,” which uses noninvasive methods such as camera traps, fecal surveys and hair surveys to establish baseline health data of wildcats like bobcats.

To learn more, listen to the episode “Bobcats benefit both human and ecological health, but their growing populations are often misunderstood.”

Banner image of a bobcat by Rhett A. Butler/Mongabay.com