Anyone who works in animal control will tell you a shelter system—no matter how functional and compassionate—cannot solve the problems of stray animals and overpopulation by itself.

Several other components are considered to be equally important, especially in New York City. They include trap-neuter-release (TNR), affordable and accessible spay/neuter programs (S/N), and education.

The city has had an increasing problem with feral cat colonies that pose a health risk to other animals and people. Susan Richmond, executive director of Neighborhood Cats (NC), estimates there are 10,000 to 100,000 ferals living "underground" in a minimum of 13,000 colonies across the five boroughs.

For a long time, animal control officials believed just exterminating feral cats would put an end to the problem. In fact, even today, because a feral is unlikely to be adopted, if it’s brought to NYC Animal Care & Control, its chances of survival are virtually nil.

Over time a grassroots movement developed organically, with Neighborhood Cats at the center. On their own initiative, volunteers began TNR, which involves trapping and neutering as many cats as possible, and then releasing them back to their colonies. Eventually, TNR was considered so effective, NC began offering training workshops, and has served as a model for similar groups both in New York and across the country. Richmond said a group "must have community involvement" for a program to be successful.

Mainstream animal organizations now recognize the importance of TNR—both the American Society for the Prevention of Cruelty to Animals (ASPCA) and the Humane Society currently offer affordable or even free spay/neutering, rabies shots and ear-tipping for ferals. Ear-tipping is a symbol a feral cat has been neutered, but is somewhat controversial because it actually involves removing a piece of the cat’s left ear.

Dr. Andrew Kaplan, a private Manhattan veterinarian, is the founder and president of The Toby Project, which received a one-year contract from the city Department of Health and Mental Hygiene to provide free S/N for feral cats. In an email, Kaplan wrote that, while the grant is for a year, "at the rate we perform [S/N], and the increase in service, we will probably use the money in six months".

The Mayor's Alliance, a nonprofit liaison between city agencies, major animal protection organizations and smaller neighborhood groups, has a program called the NYC Feral Cat Initiative providing information, education and some services, like transport and traps. One has to be a certified caretaker to carry out certain activities involving ferals.

The nonprofit Maddie’s Fund has given the Alliance millions towards S/N programs, including a recent one-year grant dedicated for private vets to sterilize ferals. That money ran out early, in the spring. Over the years, Maddie’s Fund has also provided millions for low-cost S/N as part of the grant to help the city reach No-Kill now by 2015. That grant ended last year, but Alliance president Jane Hoffman said the ASPCA is picking up the slack with five mobile vans that run seven days a week.

"Between spay/neuter surgeries done at the ASPCA's Bergh Memorial Animal Hospital and those performed by the ASPCA Spay/Neuter Operations team, the ASPCA has spayed and neutered approximately 20,000 cats and dogs so far in 2012," ASPCA spokeswoman Anita Edson wrote. "Nearly 36,000 procedures were done in 2011."

Humane education programs would be highly beneficial at addressing issues related to feral animals, proponents say. Despite state laws mandating such programs in all elementary schools under state control, dating back decades, they are rarely if ever provided.

"It's never too early to start teaching children compassion and responsibility toward animals," The New York Humane Society says. "It's also never too early to start teaching kindness, whether to animals or people, and how connected both aspects are. Unfortunately, we lose great opportunities every day in our schools, where humane education is an unfunded and overlooked mandate."