When homeless cats aren’t spayed or neutered, they can multiply quickly — a few stray cats can turn into dozens in just a year. Like urban areas across the country, Oakland has struggled with a surge in the number of feral cats in recent years, which can overwhelm neighborhoods and create unsafe conditions for the felines. Fortunately for Oakland and its free-roaming cats, a group of passionate volunteers has made it their mission to humanely tackle this seemingly intractable problem. In 2013, Sarah Rogers, a longtime animal advocate, founded Feral Change, an Oakland-based volunteer group dedicated to a technique called “trap-neuter-release,” or TNR, in which cat lovers trap feral cats, spay or neuter them, then release them back to their original location or help get them adopted when possible. It’s challenging work. Few homeless cats are eager to be trapped, which means the volunteers must demonstrate extreme patience and skill, often wandering the streets of Oakland at night targeting particularly large colonies that have taken over abandoned backyards. Though the job is tough, animal advocates and experts agree that it’s the most humane and effective way to help manage stray populations. After all, the alternative is “trap and kill” — an outcome Feral Change volunteers can’t bear to accept.