When an escaped tiger killed a San Francisco zoo visitor on Christmas, it was the biggest blow yet to an industry that has been working hard to improve its reputation.

The problem: Some animals aren’t cooperating.

In 2007, at least 10 animal escapes from U.S. zoos generated press coverage. Fugitives include a cheetah that scaled a fence at the St. Louis Zoo, a peacock that walked out of the Denver Zoo and took up residence on the front porch of a nearby house, and a geriatric spider monkey named Rena who jimmied open her cage door at the Dallas Zoo before being recaptured.

Still at large: an African white-backed vulture with a nine-foot wing span that squeezed through a fence in Dallas. “The general feeling was that she could survive out in the wild,” says Karen Hamilton, a spokeswoman for the zoo, adding that the search is ongoing.

Most animal escapes don’t result in injuries to people, and the critters are usually captured and returned home. But zoo officials say recent breakouts have forced them to talk about safety at a time when they would rather discuss topics like improved facilities and efforts to save endangered species.

The nation’s largest zoos are in the midst of a public-relations campaign led by the Association of Zoos and Aquariums — a trade group that accredits zoos — to counter recent accusations by animal-rights groups that captive creatures are mistreated. They’re launching educational campaigns about the animal aging process, for example, to show that when an animal dies it is often due to natural causes. They’re also talking publicly about incidents, including escapes, that they might not have disclosed in the past.

When an alligator named Reggie scaled a wall at the Los Angeles Zoo last August, spokesman Jason Jacobs says he decided to go public, even though the event occurred before the zoo opened. He invited reporters to come see Reggie, telling the Associated Press, “it proves to us that he’s a very smart, healthy gator.”

The AZA has also beefed up its crisis-management system. In 2006, it hired Steve Feldman from Powell Tate, a Washington PR firm, where he handled responses to plane crashes and helped environmental groups beset by scandal. Crisis-management courses are now taught at the AZA’s training program in Wheeling, W. Va.

When tests determined the May death of an eight-year-old hooded capuchin monkey at the Denver Zoo was caused by bubonic plague, spokeswoman Anna Bowie says she “put out a press release and did hold a press conference with our veterinarian” to inform the public. “You hear bubonic plague and people think, ‘oh my god, black plague, bring out your dead,'” says Ms. Bowie. She says the zoo worked with the U.S. Centers for Disease Control to tell reporters that the monkey got plague by eating an infected squirrel, and that humans are not at risk.

Ironically, many image-rattling events can be partly traced to zoos’ past attempts to improve their images. Pressured by animal-rights activists, zoos shifted over the past few decades to naturalistic habitats that are seen as more humane. Sparsely furnished cages were replaced with vegetated outdoor areas featuring few barriers beyond a trench at the perimeter.

Fewer fetters means more opportunity to flap, climb or jump away. It also tends to mean higher insurance premiums. “The more natural you make an exhibit, the more natural behaviors the animal shows,” says David Orndorff, director of the Mill Mountain Zoo in Roanoke, Va., where a giant Burmese mountain tortoise escaped in August. That was one year after Oops, a Japanese macaque monkey, went on the lam for a week.

Zookeepers say they learn through trial and error what enclosures are effective. When escapes do occur, zoo officials say the public and the media can be overly harsh. In 2003, a 300-lb gorilla named Little Joe fled Boston’s Franklin Park Zoo and accosted a child before he was apprehended at a bus stop. John Linehan, the CEO of Franklin Park’s parent organization, Zoo New England, says a TV reporter pressured him to euthanize the gorilla; he declined. “It’s not the animal’s fault,” Mr. Linehan says.

Zoos’ latest PR push emerged in 2003, following a series of Washington Post stories blaming poor care at the National Zoo in Washington for more than 20 animal deaths. Bad press continued when a gorilla named Jabari escaped from the Dallas Zoo in 2004, attacking at least one pedestrian before being shot to death; at the time, he was carrying a pair of white children’s sandals. Around that time, groups including People for the Ethical Treatment of Animals began pointing to several elephant deaths as evidence that zoos mistreated the animals.

Zoos counterattacked, saying the elephants were dying from old age, not poor care. The AZA hired an outside PR firm to head the campaign and commissioned polls to show that the public supports zoos’ elephant programs. Elephant keepers were given media training and encouraged to speak with reporters.

The AZA considers the effort a success: Legislation to ban elephants from zoos in Chicago failed in 2006, as did attempts to restrict elephant keeping in California and El Paso, Texas.

In late 2006, the AZA hired Mr. Feldman, the crisis public-relations veteran. “What you want in this PR world is someone who’s on 24/7,” says Roger Germann, who chairs the AZA’s PR committee.

Mr. Feldman says he was leaving his inlaws’ house in Alexandria, Va., after Christmas dinner when San Francisco Zoo spokesman Paul Garcia called him at about 9:15 EST, an hour after the fatal tiger attack. Mr. Feldman says he immediately began planning a response, deciding that San Francisco Zoo officials would speak about the mauling while Mr. Feldman would field general questions about feline care and safety.

On New Years Eve, the zoo hired a San Francisco-based crisis PR expert named Sam Singer. Last year, Mr. Singer represented Steve Schulman, a former Milberg Weiss partner who pleaded guilty of fraud in federal court.

Mr. Singer says the public response did not begin smoothly, and that overwhelmed zoo PR people were initially unable to counter press reports that the zoo’s response to the attack was too slow. Zoo director Manuel Mollinedo has since said he believes the tiger was provoked by the victims.

The escape is still being investigated, though the zoo has acknowledged that the tiger’s enclosure was too low. Mr. Feldman says the incident is the first time an escape resulted in fatal consequences for a visitor since the group’s accreditation program began in 1974.

He says “anti-zoo extremists” are using the tiger incident to further their attack on the industry, and says “escapes are so rare and of such a minor nature that we don’t keep statistics.”

Write to The Wall Street Journal c/o Justin Scheck at justin.scheck@wsj.com¹ and Ben Worthen at ben.worthen@wsj.com