Several chickens entered into the livestock competition of the Martha’s Vineyard Agricultural Society Fair were stolen from their cages, shattering for many the old-fashioned sense of innocence of the event while prompting officials to consider increased security measures when the fair resumes next year.

A total of four chickens were stolen last weekend, several of which had already won blue ribbons in the annual livestock competition. Fair officials believe the birds were stolen late Saturday night or early Sunday morning, although they are unsure whether someone took them during the day while the fair was in progress, or slipped into the barn at night to take them.

Eleanor Neubert, fair manager for the past 25 years, said she could not recall another year when animals were stolen. She said the heartless nature of the crime has left fair officials reeling.

“I never thought this could happen . . . this is a county fair, for crying out loud,” she said. “I think about all the time and care that went into raising those animals, only to have them stolen during the livestock competition . . . it’s such a disappointment.”

When fair officials were first alerted about the missing birds Sunday morning, they initially thought someone had brought the wrong birds home with them mistakenly, she said. But on closer inspection it seemed this was no mistake.

Only certain birds — all with white feathers — were taken from the cages while others were left behind. And the prize ribbons hanging from the cages also were left behind.

Then came a report from a 12-year-old girl working as a volunteer at the fair who said she saw a woman the day before trying to put two baby chicks into her pocketbook. The young girl told the woman she wasn’t allowed to do that; the unknown woman who may have been the thief then put the birds back and disappeared.

Three chickens owned by Samantha and Katy Smith of Chilmark were stolen, including one bird that won the Emma T. Parker Special Award for best overall bantam hen. A fourth chicken owned by the Capece family of West Tisbury was also taken.

In a letter to the editor published on Aug. 25, Heather Capece said she and her two daughters were shocked and hurt by the theft of the birds.

“We live on the Vineyard . . . why steal chickens from kids? I’d like to hope it was some misunderstanding. But the reality is someone took one of our hens out of a cage with three other chickens in it. And of course, someone tried to take baby chickens in her purse. Unbelievable,” Ms. Capece said.

Father Bill Smith said he was also at a loss to explain why someone would steal a young person’s bantam hens from the fair.

“Is this the world we live in now, where someone steals livestock from the fairgrounds? We’re talking about a child’s pet here . . . it disgusts me,” he said.

Mr. Smith was hard-pressed to understand why someone would want the bantam hens; they are relatively small, he noted, and are not great for eating, and they produce much smaller eggs than a regular chicken. Showing them in next year’s fair also seems unlikely, he said, as the birds are equipped with a metal leg band for identification. All poultry must go through a rigorous inspection from the state department of public health before it is entered into the livestock contest.

“I guess you could cut off the leg band, if you want to go through all that trouble, but then you have to go through all that work to get it inspected . . . and somebody could still recognize them as their own during the fair,” he said.

Mr. Smith said he does not blame the fair staff for the theft. “They’ve got bigger fish to fry; they don’t need to spend time looking for a chicken thief. That barn has horses that need to be fed, they have cows giving birth . . . it’s a busy place,” he said.

Ms. Neubert said officials alerted police to the thefts during the fair, although there is no open investigation or incident report on file at the West Tisbury police department. She said fair officials plan to step up security next year, although they will do it with a heavy heart.

“I wish we didn’t have to, but I guess that’s the reality,” she said. “It seems to go against what the fair is all about . . . these kids get excited every year to share their animals and educate people, and now we have to tell them to be careful; their animals might be stolen. It’s sad, really.”