In the right place, they’re familiar — meaning, part of the family. Feral cats, however, are a different animal. The word feral is defined as “in a wild state,” but in the wild, they can become a nuisance, even a danger to some other species.

They are often fed and tended to by volunteer caretakers, with the result that colonies can grow to the point that they affect residential neighborhoods.

Even when they’re beyond human habitats, they can be predators to native and threatened species that the state is trying to protect. Most recently, Hawaiian monk seals, among the most endangered marine mammals, have been infected with toxoplasmosis, a disease caused by parasites in cat feces.

And it’s been a particular concern on Kauai, where a fledgling petrel chick was killed by a feral cat, an episode that was caught on tracking cameras.

Having that evidence brings no real satisfaction to conservation officials such as Josh Atwood, invasive species coordinator for the state Department of Land and Natural Resources.

“Cats should not be part of the landscape in Hawaii in any free-roaming way,” Atwood said.

Hawaii’s feral animal count also includes a booming population of chickens wandering about. But it’s the cats that have the attention of Anna Neubauer, the president and CEO of the Hawaiian Humane Society.

Stepping up the Oahu nonprofit’s partnership with the caretaking community — healing relationships that had become strained — is among Neubauer’s top priorities. She hopes to amplify work that began 18 months ago, a collaboration with the caretakers to bring the feral cats in to be spayed or neutered and then return them to the colony, so that the population will shrink through attrition.

This approach, usually called trap-neuter-release (TNR), is not without controversy. Some nature organizations, such as the American Bird Conservancy, point to limits to the effectiveness of TNR as it’s often practiced.

Among the reports it cites is one from the University of Southern California and UCLA, which concludes that too many of these TNR programs spay and neuter too few of the cats to reduce its population. It refers to a 2004 study indicating that it takes the neutering of 71-94% of a population to cause a decline, and that’s assuming no new migration into the colony.

Other studies acknowledge that this problem — in-migration to the colony — can counter TNR efforts. One was published in 2003 in the Journal of the American Veterinary Medical Association.

However, the study also concluded that “long-term reduction of free-roaming cat numbers is feasible by TNR.” In particular, it determined that effectiveness gets a boost when paired with an aggressive program of adoption of cats from the colony that are socialized.

Neubauer maintains that TNR is what has worked for other cities and can work well here, in collaboration with other agencies and organizations.

Support from the city for spay-neuter programs go back many years, but the collaboration with caretakers in reducing feral cat colonies has been a more recent emphasis.

Taking what is considered a more humane approach to feral cats is a path of alignment between HHS and the colony caretakers and no-kill shelter advocates, often at odds with the humane society over its animal euthanasia services.

More recently, there was discord over an ordinance passed by the Honolulu City Council, changing regulations around the holding and treatment of lost or abandoned cats that are on record as having a registered owner.

But Neubauer thinks all the local groups can realign on TNR, and she plans to push for doubling the number of cats spayed or neutered from 5,000 to 10,000 a year. That is what’s required to make a difference, she said.

“I am a huge proponent of collaboration. We can’t do anything alone. We have to work together as a community,” she said. “Any kind of nonprofit work, but in particular animal welfare, is so dynamic and complex that it really takes the entire community to get it done.

“The more people and organizations we collaborate with, the more impact we’re going to have,” she said. “It’s important in particular for us to focus on cats in particular.

“Cats are a problem everywhere, just in regards to being out, the numbers on the streets, overpopulation, that sort of thing,” Neubauer added. “It’s very prevalent here … it reminds me of where a lot of communities were 20 years ago.”

Getting where Oahu needs to be is taking an investment. By the city’s accounting, it’s cost about $565,000 on the TNR services in its contract with the humane society for the feral cat population on Oahu, since the fourth quarter of 2018.

Randy Leong, deputy director of the city Department of Customer Services, said the focus on free- roaming cats began with a pilot program for 90 days. That $35,000 contract with the humane society handled an estimated 700 free- roaming cats.

This was followed by a $265,000 contract for 2019, resulting in the trapping, neutering and return of 3,500 cats to colonies. An equal allotment for the current year has the aim of handling 5,000 cats.

The approach being used is a model used in cities such as San Antonio and New York, Leong said. He thinks it can work, too.

“The volunteer care for the cats, feeding them, monitoring the size of the colony,” he added. “They know that environment, they know the colony, they’re probably living in the area, right?”

To boost the effort further and make her own 10,000-cat goal, Neubauer is looking for community fundraising support and leveraging resources through partnerships.

One of these partnerships is likely to be with DLNR, although, Atwood acknowledged, the agency has been taking a harder-edged approach lately where feral cats are concerned. The cats’ toxoplasmosis infections can affect humans — pregnant women and their unborn children, and people who are immunosuppressed. But it’s the protection of natural resources that is the department’s mission, he said.

The Hawaii Invasive Species Council, which is advisory to DLNR, last year adopted a resolution opposing the TNR approach to feral cat management, citing the danger of infection to endangered species such as the Hawaiian monk seal, the alala and the nene, as well as spinner dolphins and the red-footed booby.

DLNR itself also adopted a rule making it a violation to feed feral animals within harbors or other state properties the agency manages.

Although the department’s priority is the preservation of endangered wildlife, not the feral cats, Atwood said the department aligns with the humane society in its planned campaigns, urging pet lovers to keep their cats indoors.

Once they’re part of the free-roaming population, he said, they’re part of the problem.

“Right now we are focusing on our common areas of interest with the Humane Society, encouraging residents to keep cats indoors or contained on their property through educational campaigns,” he said.