Despite visions of quaint coops, happy birds and cheap eggs, the growing trend of raising backyard chickens in urban settings is backfiring, critics say, as disillusioned city dwellers dump unwanted fowl on animal shelters and sanctuaries.

Hundreds of chickens, sometimes dozens at a time, are being abandoned each year at the nation’s shelters from California to New York as some hipster farmers discover that hens lay eggs for two years, but can live for a good decade longer, and that actually raising the birds can be noisy, messy, labor-intensive and expensive.

“Many areas with legalized hen-keeping are experiencing more and more of these birds coming in when they’re no longer wanted,” said Paul Shapiro, spokesman for the Humane Society of the United States. “You get some chicks and they’re very cute, but it’s not as though you can throw them out in the yard and not care for them.”

That accusation is disputed by advocates of home-grown chickens, who say that a few negative incidents shouldn’t give a bad name to a practice that encourages both self-sufficiency and the consumption of sustainable food grown in a humane manner.

“We’ve experienced smell, noise, pests, etc., way more from improperly cared for dogs and cats than we have from backyard chickens,” said Rob Ludlow, owner of the fast-growing website, BackYardChickens.com, which started with 50 members in 2007 and now boasts 200,000 members. He is the author of three books, including “Raising Chickens for Dummies.”

“Hundreds of thousands of people are realizing the wonderful benefits of raising a small flock of backyard chickens, the pets that make you breakfast,” he said, noting that cities nationwide have agreed, passing ordinances making it legal to keep small flocks of urban chickens.

However, at the Farm Sanctuary headquartered in Watkins Glen, N.Y. -- which operates three shelters on two coasts -- some 225 former backyard chickens are waiting now for new homes, said National Shelter Director Susie Coston. They’re among at least 400 to 500 abandoned chickens that show up every year, including many suffering from maltreatment or illness.

“They’re put on Craigslist all the time when they don’t lay any more,” said Coston, 48. “They’re dumped all the time.”

It’s the same scenario at the Chicken Run Rescue in Minneapolis, Minn., where owner Mary Britton Clouse has tracked a steady climb in surrendered birds from fewer than 50 in 2001 to nearly 500 in 2012.

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She traces that rise to the so-called “locavore” movement, which spiked in popularity in 2008 as advocates urged people to eat more food grown and processed close to home.

“It’s the stupid foodies,” said Britton Clouse, 60, who admits she speaks frankly. “We’re just sick to death of it.”

People entranced by a “misplaced rural nostalgia” are buying chickens from the same hatcheries that supply the nation's largest poultry producers and rearing them without proper space, food or veterinary care, she said.

The most commonly available hens have been bred to be good egg layers. At the same time, backyard farmers often use enhanced feed, light or other tools to prompt hens to lay constantly. After keeping up that pace for 18 months to two years, however, hens often develop reproductive problems including oviduct diseases that can kill them, veterinarians say. However, healthy hens can live for years longer, up to a decade after they stop laying.

Because chickens are notoriously hard to sex, some backyard farmers wind up with roosters, which are often culled and killed because they can be noisy, aggressive and illegal, and, of course, they don’t lay eggs at all.

In addition to the noise, many urban farmers are surprised that chickens attract pests like rats, and predators including foxes, raccoons, hawks, and even neighborhood dogs.

When they get sick or hurt, they need care that can run into the hundreds of dollars, boosting the price of that home-grown egg far beyond even the most expensive grocery store brand.

Enthusiasts who start out with good intentions frequently wind up posting messages like this one delivered to Britton-Clouse last month:

“One of our hens grew up into a rooster and our neighbors are starting to complain. Do you know someone who might take him?”

“People don’t know what they’re doing,” Britton Clouse said. “And you’ve got this whole culture of people who don’t know what the hell they’re doing teaching every other idiot out there.”

But Ludlow, the backyard chicken enthusiast, said that “it’s very rare” that people make such mistakes or underestimate how difficult it is to raise chickens.

“While we definitely want to see more education around the lifespan and laying lifespan of chickens, we find that most people become so attached to their hens as pets, that even though they planned to eat or cull their hens at the end of their laying life, they decide to keep their girls around even without laying eggs,” he said.

Coston, the Farm Sanctuary shelter director, said she wished that were true. Most people don’t realize that chickens are funny, with quirky habits and affectionate personalities as distinct as any other pet’s.

“Oh, my god, they’re amazing,” said Coston, who frequently cuddles her chickens. “We have some of the sweetest ones here. They just sit beside you and they let you pet them. And they’re big and dumpy.”

She hopes the enthusiasm for raising backyard chickens will fade and that consumers will take a second look at their appetite for eggs and poultry.

“To go back in time sounds wonderful,” she said. “But there is not enough land on this earth to sustain the amount of meat, dairy and milk that people want.”