NEW YORK (AdAge.com) -- They were once stars. After a rough start in life -- taken from their mothers during infancy -- they found themselves on the national stage, making millions laugh during the Super Bowl. Their careers were short, two or three years at most, and now they've been shunted aside. But they're the lucky ones. Sent to finish out their lives in Florida, the four chimpanzees from the original CareerBuilder Super Bowl ads share a home with Michael Jackson's former pet, Bubbles, at the Center for Great Apes in Wauchula. They could have ended up in cages in roadside attractions, or on the nightly news, put down after going on a rampage.

Before this year's Super Bowl, it had likely been years since most Americans had seen a national TV spot featuring an ape. That's because chimpus commercialus and its kin, thanks to pressure put on marketers and ad agencies by animal-rights groups, are on the verge of extinction.

But there are still reminders. After moving away from the use of chimpanzees in its Big Game commercials, CareerBuilder has sparked a minor controversy by reviving interest in the animals that have long been a staple of big-budget TV advertising. CareerBuilder ads in last night's game returned to the theme from the company's memorable efforts in 2005 and 2006: chimpanzees as obstinate, time-wasting cubicle-mates who demonstrate the need for CareerBuilder's online job listings.

Last night's spot could mark the last for this close relative of the monkey that has ridden on Madison Avenue's back for decades.

Eighteen different ad agencies have agreed in the last few years to stop using great apes in the commercials they produce, the result of an ongoing effort started in 2008 by People for the Ethical Treatment of Animals.

Among the big firms involved are Omnicom Group's BBDO, GSD&M and Merkley & Partners; Interpublic Group of Cos.' McCann Erickson, DraftFCB and RPA; Havas' Arnold and Euro RSCG; WPP's Grey Group, Ogilvy & Mather, Young & Rubicam and JWT; and Publicis Groupe's Saatchi & Saatchi and Leo Burnett.

"The list is only going to grow," said Julia Galluci, a primatologist with PETA who studies the use of apes in commercials.

Indeed, Omnicom's DDB and TBWA/Chiat/Day, two agencies that work for marketers that have made memorable ads with chimps in the past -- Anheuser-Busch InBev and PepsiCo -- are not yet on the list.

PETA also successfully lobbied several major advertisers to modify or pull ads in 2010 when apes were featured. Pfizer edited out an orangutan used in a commercial crafted by Grey Group for its Robitussin, and decided instead to incorporate a digital image of a chimp. Dodge, AT&T and Travelers Insurance made similar moves after PETA's approach.

For its part, CareerBuilder, which created its ad in-house, said it has treated the animals involved in this year's Super Bowl plans well. "During the production of our ad, we followed the strictest guidelines to ensure our chimpanzee stars were treated well and not harmed in any way. We hired top trainers known to provide the highest standard of care for their animals. We also had a member of an animal rights group, the American Humane Association, on set during the entire filming to ensure the chimpanzees were treated with respect," the company said in a statement. "This was very important to us."

But it's not the treatment of the animals on set that is the main concern from animal-rights groups. Rather, it's the procurement and disposal of apes for acting.

Apes in the wild stay with their mothers for nearly the first decade of life, and typically nurse for the first five or six years, said Patti Ragan, founder and director of the Center for Great Apes, the private sanctuary that hosts those four CareerBuilder chimps as well as Bubbles. But to work on an ad, movie or TV program, a chimp or orangutan needs to be under the age of 8. When they pass that age, she said, "they are too dangerous and strong to work around humans" and are therefore retired. Caring for the animals after they can no longer work on shoots can require something in the neighborhood of $20,000 a year, she estimated.

Heartstring-plucking details such as these are likely not immediately clear to the consumers who thrill to monkeyshines in TV pitches. And even those who protect the chimps admit that there has been no consumer outrage. If it did, the animals wouldn't show up year after year in the Super Bowl, the nation's broadest advertising showcase.

Great apes have appeared in 10 different ads tailored for the Big Game since 2000, according to research from students of Chuck Tomkovick, a professor of marketing at University of Wisconsin-Eau Claire, who has studied Super Bowl ads for years. There's good reason: Mr. Tomkovick's recent research suggests that placing any sort of an animal in an ad increases its likability.

The ad industry's eagerness to distance itself from chimps and their cousins comes even though capturing consumer attention with TV ads has become increasingly difficult. And it arrives despite the fact consumers are more likely to stop and notice chimps and apes when spotted on the TV screen. Chimps and apes have particular appeal, said Barbara J. King, an anthropology professor at the College of William and Mary, who has studied apes and monkeys in the wild and in U.S. zoos for 30 years.

"They are like us, but they're not like us," she said. "It's exactly that strange paradox that grabs people."

Further, when it comes to convincing consumers that apes need protecting, there is a perception problem. "It looks to me like these commercials are making these animals seem cute and perfectly well-cared for," said Ms. King, the anthropology professor. "It's not clear to me from the surface of it why consumers would necessarily be concerned unless someone tells them the back story."

And PETA has been relaying that story to ad-agency executives to some effect. "The cruelty of separating baby apes from their mothers, the brutal training, and the tragic 'retirement' provide a real incentive not to use them," said Andrew Robertson, president-CEO of BBDO Worldwide.

"They are cute. They behave like humans. They are cuddly," said Tony Granger, global chief creative officer at Young & Rubicam. "But what really does it for me is understanding that the apes are taken away from their mothers. We honestly didn't know any of this."

PETA expects to press its case, Ms. Galluci said. The organization is in early talks with BBDO to create an ad campaign aimed at ad-industry employees and make them aware of the problems with using live apes in ad shoots. "It's the agencies that are writing the stories, writing the scripts for these ads," she said. Once agency executives hear the details about the simians, she added, "they are really quick to agree" not to use them any longer. Whether the entire industry apes the move remains to be seen.